Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| arthropod-borne disease in canada: a clinician's perspective from the 'cold zone'. | arthropod-borne diseases do not occur commonly in canada. nevertheless, canadians run the risk of contracting certain infections within the country during arthropod season, as well as when travelling abroad. therefore, it is important that clinicians are aware of the possible occurrence of arthropod-borne diseases, and consider them in their differential diagnoses. the present review is divided into two sections: arthropod-borne diseases or disease agents documented in canada, and imported arthr ... | 0 | 20177520 |
| is transfusion-transmitted dengue fever a potential public health threat? | dengue is an arboviruses due to single-stranded enveloped ribonucleic acid viruses, named dengue viruses (denv), that include four serotypes and are mainly transmitted via the bite of mosquitoes of the genus aedes (a. aegypti and a. albopictus). the distribution of the disease was historically limited to intertropical areas; however, during the last thirty years, the perimeter of the disease extended considerably and temperate areas are now at risk of outbreaks. the present global burden of deng ... | 0 | 25964876 |
| update on tick-borne rickettsioses around the world: a geographic approach. | tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus rickettsia. these zoonoses are among the oldest known vector-borne diseases. however, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. several species of tick-borne rickettsiae that wer ... | 0 | 24092850 |
| importance of ticks and their chemical and immunological control in livestock. | the medical and economic importance of ticks has long been recognized due to their ability to transmit diseases to humans and animals. ticks cause great economic losses to livestock, and adversely affect livestock hosts in several ways. loss of blood is a direct effect of ticks acting as potential vector for haemo-protozoa and helminth parasites. blood sucking by large numbers of ticks causes reduction in live weight and anemia among domestic animals, while their bites also reduce the quality of ... | 0 | 17048307 |
| arthropod surveillance programs: basic components, strategies, and analysis. | effective entomological surveillance planning stresses a careful consideration of methodology, trapping technologies, and analysis techniques. herein, the basic principles and technological components of arthropod surveillance plans are described, as promoted in the symposium "advancements in arthropod monitoring technology, techniques, and analysis" presented at the 58th annual meeting of the entomological society of america in san diego, ca. interdisciplinary examples of arthropod monitoring f ... | 0 | 26543242 |
| feeding period required by amblyomma aureolatum ticks for transmission of rickettsia rickettsii to vertebrate hosts. | rocky mountain spotted fever is endemic to the são paulo metropolitan area, brazil, where the etiologic agent, rickettsia rickettsii, is transmitted to humans by adult amblyomma aureolatum ticks. we determined the minimal feeding period required by a. aureolatum nymphs and adults to transmit r. rickettsii to guinea pigs. unfed nymphs and unfed adult ticks had to be attached to the host for >10 hours to transmit r. rickettsii. in contrast, fed ticks needed a minimum of 10 minutes of attachment to ... | 0 | 25148391 |
| tick-borne lymphadenopathy-like condition in an african woman in kenya. | a 30-year-old african woman in kenya succumbed to severe swollen regional lymph nodes, development of painful boils and ulcer formation and rashes at specific tick-biting sites together with an intermittent fever and headache following repeated tick bites of rhipicephalus pulchellus. she later developed nuchal lymphadenopathy-like condition and an eschar with edematous margins at bitten sites. a sustained high fever and fatigue then followed. she became well after treatment with antibiotics and ... | 0 | 24497868 |
| an insight into the microbiome of the amblyomma maculatum (acari: ixodidae). | the aim of this study was to survey the bacterial diversity of amblyomma maculatum koch, 1844, and characterize its infection with rickettsia parkeri. pyrosequencing of the bacterial 16s rrna was used to determine the total bacterial population in a. maculatum. pyrosequencing analysis identified rickettsia in a. maculatum midguts, salivary glands, and saliva, which indicates successful trafficking in the arthropod vector. the identity of rickettsia spp. was determined based on sequencing the ric ... | 0 | 24605461 |
| high prevalence of rickettsia africae variants in amblyomma variegatum ticks from domestic mammals in rural western kenya: implications for human health. | tick-borne spotted fever group (sfg) rickettsioses are emerging human diseases caused by obligate intracellular gram-negative bacteria of the genus rickettsia. despite being important causes of systemic febrile illnesses in travelers returning from sub-saharan africa, little is known about the reservoir hosts of these pathogens. we conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western kenya. of the 100 serum specimens tested from each species of domestic r ... | 0 | 25325312 |
| what's left in asymmetry? | left-right patterning is a fascinating problem of morphogenesis, linking evolutionary and cellular signaling mechanisms across many levels of organization. in the past 15 years, enormous progress has been made in elucidating the molecular details of this process in embryos of several model species. while many outside the field seem to believe that the fundamental aspects of this pathway are now solved, workers on asymmetry are faced with considerable uncertainties over the details of specific me ... | 0 | 18488999 |
| findings of scientific misconduct. | 0 | 27737130 | |
| findings of scientific misconduct. | 0 | 12666658 | |
| peripheral neuropathy due to vitamin deficiency, toxins, and medications. | peripheral neuropathies secondary to vitamin deficiencies, medications, or toxins are frequently considered but can be difficult to definitively diagnose. accurate diagnosis is important since these conditions are often treatable and preventable. this article reviews the key features of different types of neuropathies caused by these etiologies and provides a comprehensive list of specific agents that must be kept in mind. | 0 | 25299283 |
| gene expression of tissue-specific molecules in ex vivo dermacentor variabilis (acari: ixodidae) during rickettsial exposure. | ticks serve as both vectors and the reservoir hosts capable of transmitting spotted fever group rickettsia by horizontal and vertical transmission. persistent maintenance of rickettsia species in tick populations is dependent on the specificity of the tick and rickettsia relationship that limits vertical transmission of particular rickettsia species, suggesting host-derived mechanisms of control. tick-derived molecules are differentially expressed in a tissue-specific manner in response to ricke ... | 0 | 24180114 |
| asymptomatic petechial eruption on the lower legs. | the authors report an unusual case of rocky mountain spotted fever that presented as an asymptomatic petechial eruption on the lower legs. rocky mountain spotted fever is rare in new england and, as such, is typically not on the differential diagnosis when presented with such patients. what began as an asymptomatic eruption progressed to more classic signs of the disease, including a positive rocky mountain spotted fever titer. the patient was successfully treated with doxycydine and within a sh ... | 0 | 24062875 |
| reinstatement of dermacentor kamshadalus neumann (acari: ixodidae) as a valid species parasitizing mountain goats and sheep in the united states, canada, and russia. | reexamination of dermacentor albipictus (packard, 1869) holdings stored in the united states national tick collection revealed several collections of a morphologically distinct dermacentor species. comparison of these specimens with other dermacentor taxa showed that they are identical to an old taxon originally described as dermacentor variegatus kamshadalus neumann, 1908. for more than a century, this taxon was known only from the male holotype specimen collected in russia, and the name was co ... | 0 | 23926766 |
| phylogenetic analysis of myobia musculi (schranck, 1781) by using the 18s small ribosomal subunit sequence. | we used high-fidelity pcr to amplify 2 overlapping regions of the ribosomal gene complex from the rodent fur mite myobia musculi. the amplicons encompassed a large portion of the mite's ribosomal gene complex spanning 3128 nucleotides containing the entire 18s rrna, internal transcribed spacer (its) 1,5.8s rrna, its2, and a portion of the 5'-end of the 28s rrna. m. musculi's 179-nucleotide 5.8s rrna nucleotide sequence was not conserved, so this region was identified by conservation of rrna seco ... | 0 | 22330574 |
| the survival of leptospira (spirochaeta) icterohaemorrhagiae in nature; observations concerning microchemical reactions and intermediary hosts. | 1. leptospira icterohaemorrhagiae is unable to grow in the urine, either with or without the addition of suitable culture ingredients, the acidity of the urine being detrimental to the growth. it survives less than 24 hours, unless the urine is neutralized or slightly alkalized, when the period of survival is somewhat longer. if suitable nutrient ingredients are added to the neutralized or slightly alkalized urine, the organism is able to grow for about 10 days, after which multiplication ceases ... | 1918 | 19868229 |
| cultivation of rickettsia-like microorganisms from the rocky mountain spotted fever tick, dermacentor andersoni. | a systematic study of 74 ticks, the infectivity or non-infectivity of which was determined by biting experiments, inoculation of emulsions, and specific immunity tests, showed the presence in some instances of several types of microorganisms morphologically resembling the inciting microorganism of spotted fever. the most frequently isolated was b. rickettsiformis, n. sp., those less commonly encountered were b. pseudoxerosis, n. sp., and b. equidistans, n. sp. these organisms are non-pathogenic ... | 1926 | 19869142 |
| a filter-passing virus obtained from dermacentor andersoni. | an invisible, filter-passing virus, pathogenic for the guinea pig, and capable of cultivation on special media for at least seven generations, has been isolated from a tick of the species dermacentor andersoni. one of two monkeys (macacus rhesus) inoculated became infected, and in one rabbit the result was negative. the virus has been transmitted from infected guinea pigs to ticks as also in one instance by tick feeding from an infected tick to a guinea pig the presence of the virus in the tick ... | 1926 | 19869167 |
| etiology of oroya fever : v. the experimental transmission of bartonella bacilliformis by ticks (dermacentor andersoni). | experiments are reported in which bartonella bacilliformis was transmitted from infected to normal rhesus monkeys by the bite of the tick, dermacentor andersoni. a long period of feeding, both on the infected animal and on the normal animal subjected to infection, was required in order to secure positive results. the infection transmitted by the ticks was mild, but definite, as shown by the recovery of bartonella bacilliformis from the lymph nodes and blood. | 1926 | 19869219 |
| experimental infection of dermacentor andersoni stiles with the virus of lymphocytic choriomeningitis. | 1939 | 18015117 | |
| hereditary transmission of the western type of equine encephalomyelitis virus in the wood tick, dermacentor andersoni stiles. | the western type of equine encephalomyelitis virus can be passed as an hereditary infection in a tick of the family ixodidae, dermacentor andersoni stiles. under experimental conditions, this virus has been carried in this tick for two successive generations, possibly for a third, passing certainly once, and possibly twice, from the female through the eggs to the larvae. the virus-carrying larval, nymphal, and adult stages of this tick, furthermore, are capable of infecting susceptible hosts whe ... | 1941 | 19871094 |
| the microbial flora of the rocky mountain wood tick, dermacentor andersoni stiles. | 1942 | 16560577 | |
| the experimental transmission of colorado tick fever. | 1. the symptoms, history of tick bite, characteristic fever curve, and white blood cell picture should enable the physician to make a diagnosis of colorado tick fever in nearly every case. 2. the typical white blood cell picture is a depression of the total leucocytes with a shift to the left of the granulocytes. basophilic cytoplasmic bodies appear occasionally in lymphocytes 3 to 4 days after clinical recovery. 3. the disease can be transmitted serially in human beings by parenteral injection ... | 1944 | 19871406 |
| tick paralysis in beef cattle due to dermacentor andersoni. | 1945 | 21009481 | |
| the possible role of ticks as vectors of leptospire. ii. infection of the ixodid ticks, dermacentor andersoni and amblyomma maculatum, with leptospira pomona. | 1959 | 13806052 | |
| development of colorado tick fever virus in the rocky mountain wood tick, dermacentor andersoni. | 1959 | 13626953 | |
| identification of rickettsia rickettsii in the wood tick, dermacentor andersoni, by means of fluorescent antibody. | 1960 | 13688983 | |
| isolation of a virus closely related to powassan virus from dermacentor andersoni collected along north cache la poudre river, colo. | 1960 | 13838002 | |
| morphology and functioning of the mouthparts of dermacentor andersoni stiles. | 1960 | 13851716 | |
| site and mechanism of tick paralysis. | a neurophysiological investigation indicates that the paralysis produced in the dog by the wood tick, dermacentor andersoni stiles, is due to failure in the liberation of acetylcholine at the neuromuscular junction because of a conduction block in the somatic motor fibers produced by the tick "toxin". | 1960 | 14425361 |
| nonpathogenic rickettsias related to the spotted fever group isolated from ticks, dermacentor variabilis and dermacentor andersoni from eastern montana. | 1963 | 14053295 | |
| anaplasma marginale theiler observed in the gut and excreta of dermacentor andersoni stiles (dermacentor venustus marx). | 1964 | 14204828 | |
| difference of sites of attachment of dermacentor andersoni stiles to cattle in southeastern alberta and in south central british columbia, in relation to possible existence of genetically different strains of ticks. | 1965 | 14328661 | |
| collection of dermacentor andersoni (stiles) with carbon dioxide and its application in studies of colorado tick fever virus. | 1965 | 5841585 | |
| anaplasmosis. xix. a preliminary study of anaplasma marginale in dermacentor andersoni (stiles) by fluorescent antibody technique. | 1966 | 5335865 | |
| 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 |
| 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 | |
| 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 | |
| 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 |
| localization of powassan virus in dermacentor andersoni ticks by immunofluorescence. | 1969 | 4905045 | |
| recognition of anaplasma marginale theiler in dermacentor andersoni stiles (=d. venustus marx) by the fluorescent antibody method. i. smears of nymphal organs. | 1970 | 4189907 | |
| attempts to transmit bovine anaplasmosis with anopheles quadrimaculatus say (diptera: culicidae) and dermacentor andersoni stiles (acarina: ixodidae). | 1970 | 5485390 | |
| 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 | |
| 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 |
| 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 | |
| ovarian intercellular bridges in dermacentor andersoni stiles (acari : ixodidae). | intercellular bridges are present between oogonia and between oocytes of nymphs and newly molted and fasting adult dermacentor andersoni stiles. during these stages there is synchronous development of oogonia and oocytes. these bridges are unique both in their degree of development and in possessing narrow, elongated invaginations of the plasma membrane around both bases. dictyosomes are frequently present in close proximity to bridge bases and vesicles are often noted in bridges between oocytes ... | 1971 | 18631576 |
| sites of attachment of 'prairie' and 'montane' dermacentor andersoni (acarina: ixodidae) on cattle. | 1972 | 5036197 | |
| isolation and characterization of symbiotes from the rocky mountain wood tick, dermacentor andersoni. | 1973 | 4202564 | |
| 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 | |
| a proposed site of fluid secretion in the salivary gland of the ixodid tick dermacentor andersoni. | 1973 | 4127146 | |
| 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 | |
| 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 |
| 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 |
| 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 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| demonstration of anaplasma marginale theiler in ticks by tick transmission, animal inoculation, and fluorescent antibody studies. | cattle were inoculated with a virginia isolate of anaplasma marginale theiler and served as an infective source for laboratory-reared dermacentor andersoni stiles and d variabilis (say) nymphs. transstadial transmission of a marginale was demonstrated by feeding the newly molted adult ticks of both species on susceptible cattle and by inoculation of gut and salivary gland homogenates collected from adult ticks at postattachment days 5 and 7. oral secretions collected from the same group of ticks ... | 1980 | 6989298 |
| ultrastructure of anaplasma marginale theiler in dermacentor andersoni stiles and dermacentor variabilis (say). | cattle were inoculated with a virginia isolate of anaplasma marginale theiler and served as an infective source for laboratory-reared dermacentor andersoni stiles and d variabilis (say) nymphs. anaplasma marginale was demonstrated by electron microscopy in gut tissues of replete nymphal ticks and in unfed, incubated, and feeding adult ticks that were exposed to the organism as nymphs when they fed on an infected cow. the a marginale organism in replete nymphs and adult feeding ticks were morphol ... | 1980 | 7212430 |
| the role of cottontail rabbits (sylvilagus spp.) in the ecology of rickettsia rickettsii in the united states. | rocky mountain (sylvilagus nuttallii) and eastern (s. floridanus) cottontails were examined for their susceptibility to virulent and avirulent strains of the spotted fever agent, rickettsia rickettsii. both species of rabbits responded to inoculation of yolk sac suspensions containing 500 egg ld50 of either virulent or avirulent rickettsiae, with rickettsemias detectable as early as 3 days after inoculation and lasting up to 7 days. when fed upon by infected ticks, only one of three rocky mounta ... | 1980 | 7406116 |
| the induction of host resistance to tick infestation with a salivary gland antigen. | salivary gland antigen, sga, derived from partially engorged female dermacentor andersoni was shown to be capable of inducing resistance to tick infestation in guinea pigs never previously exposed to ticks. immunization regimens involved the administration of sga by different routes and with or without the use of adjuvants. induced resistance was expressed by significantly fewer larvae engorging, and the weight of larvae which did engorge was reduced. salivary gland antigen has been shown to int ... | 1981 | 7212171 |
| transmission of anaplasma marginale theiler by dermacentor andersoni stiles and dermacentor variabilis (say). | cattle were inoculated with a virginia isolate of anaplasma marginale theiler and served as an infective source for laboratory-reared dermacentor andersoni stiles and d variabilis (say) nymphs. following a molt and subsequent feeding of adult ticks on susceptible cows, transstadial transmission of a marginale occurred from cattle with parasitemias ranging from undetectable (in a carrier cow) to a peak of 27% (in an acutely ill cow). homogenates of gut tissue from unfed, incubated, and feeding ad ... | 1981 | 7224310 |
| bilateral gynandromorphism in dermacentor andersoni (acari: ixodidae): morphologic and cytogenetic analysis. | 1981 | 7288835 | |
| 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 |
| chemoprophylaxis of vector-borne anaplasmosis with sustained-release boluses. | sustained-release oxytetracycline boluses (20%) delivering 145 to 150 mg/bolus/day were administered to complement-fixation test-negative cattle at dosages of 2.0, 2.5, and 3.0 mg/kg of body weight. subsequent challenge exposure of cattle with dermacentor andersoni stiles infected with anaplasma marginale theiler indicated that treatment with the dosage of 2.5 mg/kg prevented clinical anaplasmosis and that treatment with the dosage of 3.0 mg/kg prevented disease infection. | 1981 | 7340579 |
| 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 |
| 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 |
| 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 |
| reactivation of rickettsia rickettsii in dermacentor andersoni ticks: an ultrastructural analysis. | virulent rickettsia in dermacentor andersoni lose their pathogenicity and virulence for guinea pigs when subjected to physiological stresses, such as starvation (overwintering), of its tick vector. however, incubation of infected ticks at an elevated temperature (37 degrees c) for 24 to 48 h or feeding for a time (usually greater than 10 h) induces r. rickettsii to revert to a virulent state, a phenomenon defined as "reactivation." electron microscopy reveals that the microcapsular and slime lay ... | 1982 | 6811439 |
| observations on the behaviour of dermacentor andersoni larvae infesting normal and tick resistant guinea-pigs. | in three separate experiments the behaviour of dermacentor andersoni larvae on normal and tick-resistant guinea-pigs was studied at intervals throughout 5-day infestation periods. fewer larvae survived on resistant hosts and their mean sizes were less than those of larvae on normal hosts, the differences becoming more obvious as time progressed. when measured at 32 degrees c, the peristaltic rates of midgut diverticula of the larvae surviving on resistant hosts were consistently lower than those ... | 1982 | 7070838 |
| morphologic characteristics of colonies of anaplasma marginale theiler in midgut epithelial cells of dermacentor andersoni stiles. | colonies of anaplasma marginale theiler were studied in midgut epithelial cells of adult dermacentor andersoni stiles that were infected as nymphs. colonies were categorized by light microscopy into 5 morphologic types that appear to represent stages in a developmental sequence. the mean diameter of the colony types ranged from 5.64 micrometer to type 1 colonies to 10.49 micrometers of type 5 colonies. representatives of each colony type were selected by light microscopy and were sectioned for e ... | 1982 | 7073078 |