Publications

penicillin-induced unstable intracellular formation of spheroplasts by rickettsiae.	penicillin g (greater than or equal to 20 micrograms/ml) is rapidly rickettsiacidal for intracellular rickettsia prowazekii. light and electron microscopic examinations revealed that penicillin g in culture medium induced a predictable transformation into typical enlarging spheroplasts deficient in the internal, putative peptidoglycan layer of the outer membrane. under certain conditions, spheroplasts ruptured to discharge contents into host cell cytoplasm and to leave empty shells of defective ...	1982	6809842
serological analysis of rickettsia tsutsugamushi isolates from north queensland.	fifty-two rickettsia tsutsugamushi isolates from humans, rodents and chiggers in north queensland were serologically characterized by the direct immunofluorescence test. a majority (71%) of the isolates was a mixture of two or more strains. the most frequently detected strains in the 52 isolates were ta716 (84%), ta763 (42%), ta686 (33%), and karp (31%). the gilliam strain was detected in only 4% of the isolates.	1982	6810861
intranuclear rickettsia tsutsugamushi in cultured mouse fibroblasts (l cells).		1982	6811840
entry of rickettsia tsutsugamushi into polymorphonuclear leukocytes.	factors involved in the phagocytosis and entry into polymorphonuclear leukocytes (pmns) of rickettsia tsutsugamushi were studied by electron microscopy. r. tsutsugamushi propagated in baby hamster kidney cell cultures was incubated with guinea pig peritoneal pmns in vitro at 35 degrees c. structurally intact and degenerating rickettsiae were found in phagosomes, but only intact rickettsiae escaped phagosomes and specifically entered the glycogen-rich cytoplasm. the extraphagosomal cytoplasmic ri ...	1982	6815091
doxycycline propylaxis for human scrub typhus.	the use of doxycycline, as a prophylactic antibiotic against scrub typhus was investigated in a prospective, randomized, double-blind study. twenty volunteers were divided into two similar groups. beginning three days before exposure to leptotrombidium fletcheri chiggers infected with rickettsia tsutsugamushi, and continuing for six weeks after exposure, one group received weekly 200-mg oral doses of doxycycline and the other group received a placebo. nine of 10 doxycycline-treated subjects rema ...	1982	6815282
[epidemiological, immunological and etiological study on tsutsugamushi disease in miyazaki district].		1982	6818301
[growth of rickettsia tsutsugamushi, isolated in miyazaki district, in bsc-1 cell].		1982	6818302
the effect of mouse age on the determination of rickettsia tsutsugamushi virulence.	the effect of age on the susceptibility of icr mice to lethal intraperitoneal (ip), rickettsia tsutsugamushi infections was tested with five virulent strains--karp, kato, gilliam, ta763, and th1817--and three strains of reduced virulence--ta678, ta686, and ta716. susceptibility differences were noted only in the icr mice inoculated with two of the strains of reduced virulence, ta716 and ta678. with both strains, mice in the 12-weeks and younger age groups had lower death rates than did mice in t ...	1982	6819371
serologic analysis of scrub typhus isolates from the pescadores and philippine islands.		1982	6819372
host defenses in experimental scrub typhus: delayed-type hypersensitivity responses of inbred mice.	delayed-type hypersensitivity responses of inbred mice during the course of lethal and chronic infections with strains of rickettsia tsutsugamushi were evaluated by using the influx of radiolabeled cells into antigen-injected ears. congenic strains of c3h mice, which previously have been shown to be resistant (c3h/rv) or sensitive (c3h/hedub) to lethal intraperitoneal infection with the gilliam strain of rickettsiae, both expressed delayed-type hypersensitivity early in the course of infection ( ...	1982	6797944
effect of immune serum on infectivity of rickettsia tsutsugamushi.	hyperimmune antirickettsial serum was shown to prevent the attachment/penetration stage of rickettsia tsutsugamushi infection of suspended chicken cells. the extent of the inhibition depended on the serum concentration but not on the presence of complement. the neutralizing activity was reduced by prior adsorption of immune serum with staphylococcal protein a or with intact rickettsiae but was not affected by adsorption with target cells. in the neutralization tests, there was no cross-reactivit ...	1983	6137458
role of t-lymphocytes in production of antibody to antigens of rickettsia tsutsugamushi and other rickettsia species.	the requirement of thymus-dependent lymphocytes for antibody production to rickettsia tsutsugamushi, rickettsia akari, rickettsia conorii, and rickettsia typhi was investigated by comparing antibody production in athymic (nu/nu) or thymus-bearing balb/c mice. athymic balb/c mice produced antibody after infection with r. akari, r. conorii, and r. typhi as measured by indirect fluorescent antibody titration or radioimmunoassay. antibody production in these mice was a great or greater than in the t ...	1983	6223883
gamma-irradiated scrub typhus immunogens: development of cell-mediated immunity after vaccination of inbred mice.	mice immunized with three injections of gamma-irradiated karp strain of rickettsia tsutsugamushi were evaluated for the presence of cell-mediated immunity by using delayed-type hypersensitivity, antigen-induced lymphocyte proliferation, and antigen-induced lymphokine production. these animals also were evaluated for levels of circulating antibody after immunization as well as for the presence of rickettsemia after intraperitoneal challenge with viable karp rickettsiae. after immunization with ir ...	1983	6185433
development of specific and cross-reactive lymphocyte proliferative responses during chronic immunizing infections with rickettsia tsutsugamushi.	the development of antigen-responsive lymphocytes was followed in mice immunized with the gilliam, karp, or kato strains of rickettsia tsutsugamushi by utilizing an in vitro lymphocyte proliferation assay. subcutaneous immunization with viable rickettsiae of all three strains resulted in the appearance of lymphocytes in the spleen responding to irradiated tissue culture-grown rickettsiae used as stimulating antigens. although all animals demonstrated antigen-induced proliferation elicited by hom ...	1983	6187688
effect of antibody on entry of rickettsia tsutsugamushi into polymorphonuclear leukocyte cytoplasm.	the effects of rickettsial antibodies on the entry of rickettsia tsutsugamushi, gilliam strain, into guinea pig polymorphonuclear leukocyte cytoplasm were studied by electron microscopy. immunoglobulin g fractions were obtained from four rabbit antisera against: yolk sac-propagated rickettsiae; baby hamster kidney cell (bhk-21)-propagated rickettsiae; formaldehyde-fixed, bhk-21 cell-propagated rickettsiae; and glutaraldehyde-fixed, bhk-21 cell-propagated rickettsiae. a fuzzy coating was observed ...	1983	6403463
growth pattern of rickettsia tsutsugamushi in irradiated l cells.	irradiated l cells infected with rickettsia tsutsugamushi were studied under the electron microscope to define the morphological growth pattern of the organism. for 2 days after inoculation, no rickettsiae were found either extra- or intracellularly; after 2 days multiple rickettsiae appeared within the host cells without morphological evidence of their entry. these observations showed that the rickettsiae within the cell were assembled in situ by segregation of portions of the granular cytoplas ...	1983	6404890
assembly of rickettsia tsutsugamushi progeny in irradiated l cells.	in the assembly of rickettsia tsutsugamushi progeny in irradiated l cells, nascent forms first appear as undemarcated foci in the host cell granular cytoplasm, in which electron-lucent filamentous (f) and electron-dense granular (g) areas differentiate. morphological observations indicated that the assembly involves formation of a filamentous network in the f area, manufacture of rickettsial ribosomes in the g area, and formation of mildly electron-dense fuzzy zones, along which a double membran ...	1983	6404892
development of antibody to rickettsia tsutsugamushi in soldiers in malaysia.	malaysian, british and new zealand soldiers were tested for evidence of infection with rickettsia tsutsugamushi after several weeks' exposure to the infection during field exercises in malaysia. 39 (5.0%) of 787 british and new zealand soldiers developed immunofluorescent antibody (ifa) to r. tsutsugamushi to a titre of 1:50 and two (0.3%) to a titre of 1:100. 11 (1.5%) of 751 malaysian soldiers also developed low titres less than or equal to 1:100. these low antibody levels were not correlated ...	1983	6408770
activation of macrophages for killing of rickettsiae: analysis of macrophage effector function after rickettsial inoculation of inbred mouse strains.		1983	6408905
parameters of cellular immunity in acute and chronic rickettsia tsutsugamushi infections of inbred mice.		1983	6408906
penetration of rickettsia tsutsugamushi into cultured mouse fibroblasts (l cells): an electron microscopic observation.	the mechanism of penetration of purified rickettsia tsutsugamushi (gilliam strain) into cultured mouse fibroblasts (l cells) was examined by electron microscopy. after 10-40 min of infection, rickettsiae in the process of being phagocytized were often seen on the cell surface. these were restricted to the rickettsiae which seemed to be intact in morphology, while heavy plasmolyzed ones were never phagocytized. additionally, rickettsiae were taken up individually into a phagosome, and phagocytosi ...	1983	6410159
diagnostic criteria for scrub typhus: probability values for immunofluorescent antibody and proteus oxk agglutinin titers.	the sensitivities and specificities of the indirect microimmunofluorescent antibody (ifa) and weil-felix (oxk) tests for scrub typhus were established for a range of titers using groups of diseased and control (other febrile illnesses) patients diagnosed by other methods. at a cut-off point of greater than or equal to 1:400, the ifa test was 0.96 specific, and at greater than or equal to 1:320, the oxk was 0.97 specific. using either these highly specific levels of antibody or other rigorous dia ...	1983	6414321
association of an inflammatory i region-associated antigen-positive macrophage influx and genetic resistance of inbred mice to rickettsia tsutsugamushi.	strains of c3h mice differing in susceptibility to intraperitoneal infection with the gilliam strain of rickettsia tsutsugamushi were used to investigate the role of the i region-associated (ia) antigen-bearing macrophage in the genetic resistance of mice to this organism. resistant mice (c3h/rv) were found to produce a quantitatively greater ia antigen-positive macrophage response after infection compared to mice (c3h/hedub) which underwent a lethal infection. the macrophage influx produced in ...	1983	6417017
observations on the ultrastructure and distribution of rickettsia tsutsugamushi in naturally infected leptotrombidium (leptotrombidium) arenicola (acari: trombiculidae).		1984	6420571
lack of transplacental infection with scrub typhus organisms in laboratory mice.	female mice were inoculated with either a virulent or avirulent strain of rickettsia tsutsugamushi before (1 month and 1 week) or after (approximately 10 days) impregnation. from each group, two pregnant mothers were killed on day 20 post-impregnation, and fetuses and placentas were examined for rickettsiae. organisms were isolated from 80% of placentas but not from the fetuses. immediately following parturition, litters from 50% of the infected mothers were exchanged with litters from uninfecte ...	1984	6424486
rickettsial diseases of the far east: new perspectives.	the rickettsial disease of man found only in asia is mite-borne (scrub) typhus, caused by rickettsia tsutsugamushi. unique to southern japan is a little-known human mononucleosis-like disease caused by rickettsia sennetsu. in 1981 and 1982, there was a remarkable resurgence in the number of reported cases of mite-borne typhus in japan after some years of virtual absence. recent studies of r sennetsu have resulted in its reclassification to the genus ehrlichia, members of which until now have bee ...	1984	6425420
[tsutsugamushi disease--on the recent multiple incidences of a new type].		1984	6433079
gamma interferon production in response to homologous and heterologous strain antigens in mice chronically infected with rickettsia tsutsugamushi.	the ability of antigen-responsive, thymus-derived lymphocytes to produce immune (gamma) interferon was investigated during the development and expression of cellular immunity to rickettsia tsutsugamushi. c3h/hedub mice infected subcutaneously with the gilliam strain developed the ability to produce serum interferon in response to intravenously inoculated antigen which correlated with the development of resistance to intraperitoneal rechallenge. antigen-responsive lymphocytes, measured by interfe ...	1984	6434427
isolation of rickettsia tsutsugamushi antigenically different from kato, karp, and gilliam strains from patients.	rickettsia tsutsugamushi strains from three recent patients of tsutsugamushi disease in niigata prefecture were isolated primarily in mice and then in l cell cultures. by this procedure, low virulent strains to mice, as well as high virulent ones, could be isolated and cultivated serially in l cell cultures, suggesting the usefulness of l cells for isolation of this species of rickettsia. each newly isolated strain was identified as a member of r. tsutsugamushi from the results of cross immunolo ...	1984	6438448
[use of the low virulent strain antigens in serological diagnosis of tsutsugamushi disease].		1984	6439785
[immunological studies of rickettsial infection--experimental rickettsia tsutsugamushi infection in nude mice].		1984	6439791
electron microscopic studies on intracellular multiplication of rickettsia tsutsugamushi in l cells.	the mechanism and kinetics of intracellular growth of rickettsia tsutsugamushi were investigated by electron microscopic observations, parallel with quantitative analysis by counting the rickettsiae seen in electron micrographs and by plaque assay for infectivity of the culture. the observations demonstrated the existence of electron-less dense and -dense types of rickettsiae in the early stage of infection, binary fission and the process of release of the microorganisms in the host cell cytopla ...	1984	6441107
scrub typhus and chiggers in northern thailand.	it was reconfirmed that l. deliense was the most dominant chigger during the rainy season in northern thailand. overall prevalence of igg antibody against r. tsutsugamushi among the rural villagers in the northern most part of thailand was nearly 60% at the level over 1 : 10 by an indirect immunofluorescent test. the level of igg and igm antibody titers was considerably high as greater than or equal to 1 : 2560 in some sera, but did not markedly vary by age groups or sexes. based on detection of ...	1984	6441267
[epidemiology of tsutsugamushi disease in hokuriku district, japan. 1. prevalence of antibody to rickettsia tsutsugamushi].		1984	6442722
[use of the rickettsia tsutsugamushi tissue culture antigen in serological investigation].		1984	6443072
production of gamma interferon in mice immune to rickettsia tsutsugamushi.	c3h/he mice immunized by subcutaneous infection with rickettsia tsutsugamushi gilliam were examined for the production of immune interferon after intravenous administration of irradiated strain gilliam antigen, in supernatants of immune lymphocytes stimulated with specific antigen, and after a secondary challenge with viable rickettsiae. mice administered various doses of irradiated whole-organism antigen 28 days after immunization showed circulating levels of interferon which peaked 4 h after i ...	1984	6317573
immunosuppression associated with the development of chronic infections with rickettsia tsutsugamushi: adherent suppressor cell activity and macrophage activation.	measures of general immunocompetency such as lymphocyte responses to mitogens and alloantigens and the ability to produce antibody to t-dependent and t-independent antigens were evaluated during the development of chronic infections with rickettsia tsutsugamushi resulting from subcutaneous infection of balb/c mice. it was found that a transient immunosuppression was demonstrable regardless of the infecting strain of rickettsiae; however, the immunosuppression produced by the karp and kato strain ...	1985	2931378
development of antigen-specific cell-mediated immune responses after infection of cynomolgus monkeys (macaca fascicularis) with rickettsia tsutsugamushi.	cynomolgus monkeys were evaluated for cellular immune responses after infection with the karp strain of rickettsia tsutsugamushi. antibody and clinical signs of localized and systemic infection were also evaluated. animals challenged with homologous or heterologous strains at various times after a primary infection were also followed up. naive monkeys developed eschars, lymphadenopathy, rickettsemia, and elevated body temperatures. antibody in these animals was igm followed by igg. lymphocyte pr ...	1985	2413138
identification and partial characterization of rickettsia tsutsugamushi major protein immunogens.	strains of rickettsia tsutsugamushi so far examined have either three or four quantitatively predominant proteins, which apparently are surface proteins and which range in size between 50 and 63 kilodaltons. these polypeptides also were the major immunogens detected by polyacrylamide gel electrophoresis of extracted rickettsial proteins which had been precipitated by hyperimmune rabbit sera. the major proteins from different rickettsial strains share some epitopes, as evidenced by the lack of st ...	1985	2415453
pathology of toxic death in mice following intravenous injection of rickettsia tsutsugamushi strain gilliam: examination by light and scanning electron microscopy.	the pathologic manifestations of the toxic death elicited by the iv injection of mice with rickettsia tsutsugamushi strain gilliam were examined by light and scanning electron microscopic techniques to ascertain the cause of death. light microscopic examinations of hematoxylin and eosin-stained sections of organs suggested the presence of fluid in the lungs; this was confirmed by an increase in the weight of the lungs of moribund mice. scanning electron microscopy of blood cells demonstrated a m ...	1985	2416973
[antigenic structure of the rickettsiae].		1985	2418607
identification of strain-specific and group-reactive antigenic determinants on the karp, gilliam and kato strains of rickettsia tsutsugamushi.	hybridoma antibodies (hab) were prepared against the karp, gilliam and kato strains of rickettsia tsutsugamushi and were examined for homologous and heterologous reactivity using an indirect immunofluorescence assay. strain-specific hab demonstrated homologous ifa titers ranging from 1/320 to 1/1,280 and did not react (less than 1/10) with the heterologous strains. the cross-reactive hab generally reacted equally with all three strains in the scrub typhus group; however, there were some hab that ...	1985	2422967
[effect of antibiotics on the persistence of rickettsia].		1985	3922156
analysis of polypeptide composition and antigenic components of rickettsia tsutsugamushi by polyacrylamide gel electrophoresis and immunoblotting.	polyacrylamide gel electrophoresis of lysates of purified rickettsia tsutsugamushi revealed as many as 30 polypeptide bands, including major bands corresponding to molecular sizes of 70, 60, 54 to 56, and 46 to 47 kilodaltons. compared with the polypeptide composition of the rickettsiae of gilliam, karp, and kato strains and a newly isolated shimokoshi strain, the major polypeptide in the kato strain (54-56k) and in the karp strain (46-47k) migrated a little faster and slower, respectively, than ...	1985	3922893
immunological studies of experimental tsutsugamushi disease in congenitally athymic (nude) mice.	athymic mice were taken ill and died from infection with the high virulence as well as the low virulence strains of rickettsia tsutsugamushi, and they did not improve in spite of tetracycline therapy. moreover, neither 7s nor igm antibody was detected by immunofluorescent antibody method in serum samples of athymic mice infected with the high virulence strain. although immune serum-transfer exhibited some protective effect in athymic mice infected with the high virulence strain, it was far lower ...	1985	3923854
purification of cell envelopes of rickettsia tsutsugamushi.		1985	3929033
[studies on tsutsugamushi disease in gifu prefecture. i. isolation of rickettsia tsutsugamushi from wild rodents at a new area and epidemiological studies on patients and latent patients in the prefecture].		1985	3932534
[in vitro susceptibility of recent clinical isolates of rickettsia tsutsugamushi to chemotherapeutic agents].		1985	3932536
[first case of tsutsugamushi disease in fukui prefecture with isolation of rickettsia from its donated blood].		1985	3932538
developmental sequence and surface membrane assembly of rickettsiae.		1985	3933409
a scanning and transmission electron microscopic examination of rickettsia tsutsugamushi-infected human endothelial, mrc-5, and l-929 cells.	monolayers of primary human endothelial cells were infected with the karp strain of rickettsia tsutsugamushi and examined by scanning and transmission electron microscopy. the results were compared with those obtained with similarly infected l-929 and mrc-5 cells and with uninfected cells of all three types. the rickettsiae grew to slightly higher titers in the human endothelial cells. transmission electron microscopy revealed significant changes in the host cell organelles; a reduction in ribos ...	1985	3934435
epidemiological studies on the background of the endemic occurrence of tsutsugamushi disease in toyama prefecture. i. epidemiology of infection with rickettsia tsutsugamuchi among field rodents in endemic and nonendemic areas.	in order to clarify the epidemiological background of the endemic occurrence of tsutsugamushi disease in toyama prefecture, japan, since 1978, comparative surveys have been carried out between endemic and nonendemic areas. rickettsia tsutsugamushi (rt) was isolated at a rate of about 36% (158/439) from field rodents in the endemic area while it was not isolated from any of 280 in nonendemic areas. in all of six stations in the endemic area, a significantly high proportion of rodents were found t ...	1985	3934506
[tsutsugamushi disease, in special relation to the new type disease].		1985	3935745
[trans-ovarian infection of rickettsia tustsugamushi in trombicula kaohuensis (sp. nov.)].		1985	3937601
[studies on tsutsugamushi disease in gifu prefecture. 2. a speculation on the vector].		1985	3938463
[studies on epidemiological and diagnostic problems in tsutsugamushi disease. with special reference to 9 cases occurring in gifu prefecture, japan].		1985	3938471
evidence of spotted fever rickettsial infection in japan as demonstrated by the indirect immunoperoxidase test.		1985	3938518
proliferating sites of rickettsia tsutsugamushi in mice by different routes of inoculation evidenced with immunofluorescence.	the sites of multiplication of rickettsia tsutsugamushi in mice by different routes of inoculation were investigated by means of immunofluorescence. r. tsutsugamushi (kato, karp, gilliam and miyake strains) inoculated by intraperitoneal route multiplied significantly in mesothelial and inflammatory cells of the peritoneal cavity of ddd and balb/c (nu/nu) mice. the rickettsial growth was not detected in parenchymal cells of the liver, spleen, kidneys and lymph nodes of ddd mice, but slightly obse ...	1985	3938824
[trombicula gaohuensis sp.nov.:--a new vector of tsutsugamushi disease].		1985	3939193
a serological survey of scrub, tick, and endemic typhus in sabah, east malaysia.	a seroepidemiological survey of 837 people and 383 febrile patients was performed in rural areas of sabah. we determined that the rickettsial diseases scrub typhus and endemic typhus were uncommon causes of febrile illness, as was tick typhus, except in forest dwelling peoples. the rate of occurrence of sfgr specific antibody was 16.5% among 412 forest dwellers, indicating that tick typhus may be a frequent cause of illness in this population.	1986	3107139
effect of sublethal gamma radiation on host defenses in experimental scrub typhus.	the effect of sublethal gamma radiation on inbred mice chronically infected with scrub typhus rickettsiae was examined. inbred mice which were inoculated with the gilliam or karp strain of rickettsia tsutsugamushi by the subcutaneous route harbored the infection for at least 1 year. irradiation of these animals at 12 or 52 weeks postinoculation with normally sublethal levels induced a significantly higher percentage of rickettsemic mice (recrudescence) than was seen in the unirradiated, similarl ...	1986	3011671
mechanisms of immunity to rickettsial infection: characterization of a cytotoxic effector cell.	rickettsiae, as other intracellular bacteria, are relatively sequestered from the effects of antibody and local antibody-independent responses. considering the obligate intracellular nature of rickettsia, the exact mechanisms by which lymphocytes and macrophages encounter rickettsial antigens and eliminate the infection depends upon the appropriate presentation of antigen to the immune system. we demonstrate here that cells taken from the spleens of rickettsia typhi- or r. tsutsugamushi-infected ...	1986	3080523
production and characterization of monoclonal strain-specific antibodies against prototype strains of rickettsia tsutsugamushi.	we have developed 18 hybridoma cell lines which secrete murine monoclonal strain-specific antibodies to prototype strains of rickettsia tsutsugamushi: nine anti-gilliam, four anti-karp and five anti-kato antibodies. all the monoclonal antibodies reacted only with their homologous strains in direct and indirect immunofluorescence (if), or indirect immunoperoxidase (ip) test. by if and ip tests with the monoclonal antibodies, 22 strains of r. tsutsugamushi, which were newly isolated from mites, fi ...	1986	3095611
immunological properties of rickettsia tsutsugamushi, kawasaki strain, isolated from a patient in kyushu.	nine isolates of rickettsia tsutsugamushi were obtained from patients with tsutsugamushi disease (scrub typhus) in miyazaki prefecture in kyushu. immunological analyses of these patients' sera and the isolates were performed by indirect immunofluorescence, indirect immunoperoxidase or immunoblotting techniques. in the analysis of reactions of the patients' sera with the prototype strains gilliam, karp, and kato and with the isolates, sera from two patients, including kawasaki, showed similar pro ...	1986	3095612
[present status of tsutsugamushi disease, especially its epidemiology, clinical features and etiological diagnosis in japan].		1986	3095984
[a case of tsutsugamushi disease with isolation of rickettsia from peripheral blood and tsutsugamushi disease in japan].		1986	3097353
suppression of lymphocyte responsiveness during acute rickettsia tsutsugamushi infection in mice.	lymphocytes from inbred balb/cyj mice infected subcutaneously with 10(3) mld50 of rickettsia tsutsugamushi karp strain were unresponsive to rickettsial antigens and phytohemagglutinin in the lymphocyte transformation assay between 11 and 28 days post-infection. there was, however, no correlation between this suppressed responsiveness to rickettsial antigens and the immune capacity to resist a normally lethal ip challenge with the karp strain. fourteen days after infection, these mice survived a ...	1986	3097359
detection of surface antigen in rickettsia tsutsugamushi infected mouse reticuloendothelial cells.	antibody produced by immunizing cba/caj mice with re cells from c57b1/6j mice infected 14 days earlier with r. tsutsugamushi gilliam strain bound readily to gilliam strain non-cell associated rickettsiae and less readily to the periphery of infected re cells. conversely, antibody produced by immunizing with re cells infected 21 days earlier did not bind to gilliam rickettsiae but bound to the surface of re cells from mice infected 21 days earlier. this binding was not related to alloantibodies b ...	1986	3097832
two new species of leptotrombidium (acari: actinedida: trombiculidae), probable vectors of scrub typhus in thailand.		1986	3098976
antigens of virulent and attenuated rickettsia tsutsugamushi.	we studied the antigens present in l929 mouse fibroblast or rabbit testicular cells, which had been infected or not with a prototype strain of rickettsia tsutsugamushi, the causal agent of scrub typhus, and its attenuated variant. immunoblotting revealed four antigens, designated 1, 1a, 2 and 3, which appeared to be specifically associated with infection with this organism. antigens 1 and 1a had similar mol. wt of about 60 kd and antigen 2 and 3 had mol. wts of 45 kd and 28 kd respectively. wher ...	1986	3102133
molecular cloning and expression of rickettsia tsutsugamushi genes for two major protein antigens in escherichia coli.	several polypeptide antigens of rickettsia tsutsugamushi are recognized by human or primate convalescent sera and may be important protective immunogens. molecular cloning and expression of the genes encoding the 110k (110 kilodalton) and 56k polypeptide antigens of r. tsutsugamushi karp were accomplished in the lambda gt11 expression vector system. southern blot analysis with the cloned fragments for the 56k polypeptide antigen (0.7 kilobases) and the 110k polypeptide antigen (5.4 kilobases) co ...	1987	3106214
use of conversion adaptors to clone antigen genes in lambda gt11.	a strategy has been devised and tested to employ ecori conversion adaptors for cloning 5' cohesive-ended restriction fragments into the unique ecori site of the lambda gt11 expression vector. five lambda gt11 chromosomal libraries were constructed with rickettsia tsutsugamushi genomic dna digested with restriction enzymes generating five different 5' cohesive ends. recombinant phage yields as high as 10(7) plaque forming units were achieved without amplification of the five libraries. sequences ...	1987	2959169
factors influencing rickettsia tsutsugamushi infection of cultured cells.	several factors which influence rickettsia tsutsugamushi infectivity of, and replication in, cultured cells have been investigated in order to establish standard laboratory conditions for reliable quantitation and maximization of rickettsial yield and to begin to explore the nature of the relationship between the rickettsia and its host cell. the extent of scrub typhus rickettsial association with host cells was dependent on the rickettsial and target cell concentrations and on the medium in whi ...	1987	3107411
improved plaque assay for rickettsia tsutsugamushi.	the assay of rickettsia tsutsugamushi infectivity by plaquing has been improved substantially by a number of changes which were based on our understanding of factors which enhance scrub typhus rickettsial infection of, and replication in, cultured cells. greater numbers of plaques and/or larger plaques resulted from: use of tissue culture medium instead of brain heart infusion broth as the rickettsial diluent; plaquing in a contact-inhibited mouse embryo cell line rather than in growth-inhibited ...	1987	3107412
deficiency of peptidoglycan and lipopolysaccharide components in rickettsia tsutsugamushi.	analyses of chemical composition in whole cells of rickettsia tsutsugamushi were performed and compared with those of the other rickettsiae and gram-negative bacteria. the results indicated that r. tsutsugamushi does not contain detectable amounts of 3-deoxy-d-mannooctulosonic acid, heptose, muramic acid, or glucosamine (less than 2, less than 2, less than 3, and less than 3 nmol/mg, respectively). the microorganism was found to contain four kinds of fatty acids (16:0, 18:0, 18:1, and 18:2), but ...	1987	3114150
[immunological studies of rickettsial infection establishment and characterization of rickettsia tsutsugamushi antigen-specific t cell line].		1987	3117947
lysis of cells infected with typhus group rickettsiae by a human cytotoxic t cell clone.	cytolytic human t cell clones generated in response to the intracellular bacterium rickettsia typhi were characterized. growing clones were tested for their ability to proliferate specifically in response to antigens derived from typhus group rickettsiae or to lyse targets infected with r. typhi or rickettsia prowazekii. two clones were able to lyse targets infected with typhus group rickettsiae. one of these clones was more fully characterized because of its rapid growth characteristics. this c ...	1987	3121731
study on leptotrombidium gaohuensis sp. nov., newly discovered vector of tsutsugamushi disease.		1987	3123167
[production and characterization of the monoclonal antibodies to rickettsia tsutsugamushi].		1987	3123571
epidemiological studies on the background of the endemic occurrence of tsutsugamushi disease in toyama prefecture. ii. anti-rickettsia tsutsugamushi antibody-positive rate in inhabitants of endemic and nonendemic areas.	with a view to clarifying the actual state of inapparent infection of tsutsugamushi diseases, inhibitants of endemic and nonendemic areas were screened for anti-rickettsia tsutsugamushi antibody (anti-rt antibody) by the indirect immunofluorescence test. the anti-rt antibody-positive rate in the inhabitants of the endemic area (about 50%) was statistically significantly higher than that in the nonendemic area (14.7%). the antibody titer in the inhabitants of the endemic area was 10-160, and the ...	1987	3123897
the diagnosis of scrub typhus: an evaluation.		1987	3123899
[microbiological studies on rickettsia tsutsugamushi].		1987	3126288
establishment and characterization of a t-cell line specific for rickettsia tsutsugamushi.	to study the immunological protective system against rickettsial infection, a t-cell line specific for rickettsia tsutsugamushi antigen was established by long-term culture of splenocytes from mice immunized with live gilliam strain r. tsutsugamushi and then propagated in the presence of homologous rickettsial antigen and syngeneic filler cells. the characteristics of the t-cell line and its capacity to induce antirickettsial protection in vivo were studied. flow cytometric analysis demonstrated ...	1987	2443453
[immunological analysis of newly isolated strains of rickettsia tsutsugamushi using monoclonal antibodies].		1987	2452853
comparative evaluation of the indirect immunoperoxidase test for the serodiagnosis of rickettsial disease.	an indirect immunoperoxidase test was compared with an indirect fluorescent antibody test and the weil-felix oxk test for serodiagnosis of scrub typhus by measuring the rickettsial antigen specific activity of igg, igm, and whole globulin. acute and convalescent sera from 50 rickettsia tsutsugamushi isolate-positive scrub typhus patients and from 45 febrile patients diagnosed as having diseases other than scrub typhus were tested. the receiver operating characteristic for each test showed that t ...	1988	3128129
effect of rickettsial antigen-specific t cell line on the interaction of rickettsia tsutsugamushi with macrophages.	the effect of rickettsial antigen-specific t cell line on macrophages infected with rickettsia tsutsugamushi was studied. it was suggested that the t cells could produce a factor which acts cytotoxically and selectively on infected macrophages.	1988	3134599
recognition of typhus group rickettsia-infected targets by human lymphokine-activated killer cells.	lymphokine-activated killer cells caused significant lysis of target cells infected with typhus group rickettsiae (tgr) but not cells infected with rickettsia tsutsugamushi. monoclonal and polyclonal antibodies against tgr or tgr-infected cells failed to bind specifically to infected targets, as determined by flow cytometry or by immunoprecipitation of radiolabeled cell surface proteins. major unaltered antigenic determinants of tgr therefore cannot be detected on the surface of infected targets ...	1988	3137174
[epidemiology of tsutsugamushi disease in hokuriku district, japan. 2. seasonal observations of vectors and rickettsial pathogens at fixed points, associated with these distributions].		1988	3137292
newly isolated strains of rickettsia tsutsugamushi in japan identified by using monoclonal antibodies to karp, gilliam, and kato strains.	four isolated strains of rickettsia tsutsugamushi from patients in a new endemic area of japan were tested for antigenicities by using 12 monoclonal antibodies to karp, gilliam, and kato strains. it was suggested that one isolate was karp related and that the others were two independent strains.	1988	3141468
[ecological survey on rickettsia tsutsugamushi in wild rodents in a rural area, tama, in tokyo].		1988	3143788
electron microscopic observations of the embryo leptotrombidium (leptotrombidium) pallidum naturally infected with rickettsia tsutsugamushi.	embryos of leptotrombidium (leptotrombidium) pallidum mites naturally infected with rickettsia tsutsugamushi were examined by electron microscopy. rickettsiae were not found in eggs just after oviposition, but were easily detected in cells at the various parts of the embryos just before hatching, indicating that the rickettsiae are surely vertically transmitted from infected adult mites to the larvae through embryos, and the rickettsiae may multiply in situ during the developing process of the e ...	1988	3145388
[pathogenic agents of rickettsia tsutsugamushi].		1988	3145992
[susceptibilities of recent clinical isolates of rickettsia tsutsugamushi to chemotherapeutic agents in vitro].		1988	3146604
immunoblotting analysis of anti-rickettsial antibodies produced in patients of tsutsugamushi disease.	the reactivity of sera from patients of tsutsugamushi disease (scrub typhus) with the antigenic polypeptides of rickettsia tsutsugamushi was analyzed by the immunoblotting method. the reactivity varied greatly among the sera of individual patients tested. igg and igm antibodies of most patients reacted with the 54-56 kilodalton (54-56k) polypeptide located on the rickettsial surface, suggesting that this polypeptide is a predominant antigen in the infection. other polypeptides of 60k, 50-52k, 46 ...	1988	3146683
evaluation of the whole blood lymphocyte transformation assay for scrub typhus exposure: adaptability to field sample collection.	the optimal conditions for the determination of exposure to scrub typhus by the whole blood lymphocyte transformation assay was 7 days culture of 10% blood in rpmi 1640 medium supplemented with 10% human ab-negative serum and l-glutamine with 50-200 micrograms protein/ml of karp, kato, or gilliam strain membrane antigen. a simple exponentially decaying linear model shows the decrease in lymphocyte viability, the ability of sensitized cells to be stimulated with pha mitogen, and the corresponding ...	1988	3149355
transovarial transmission of rickettsia tsutsugamushi in leptotrombidium pallidum successively reared in the laboratory.	engorged larvae of leptotrombidium pallidum were collected from a wild rodent, apodemus speciosus, and reared in a plastic container fed with fresh eggs of colembolla, sinella curviseta, under moist conditions at 25 degrees c. fully developed adults were separated into individual containers and a proven male was paired with a suspected female. of the pairings, 38 produced larvae and 4 infected colonies were established. females in these colonies were shown to be infected with karp type of ricket ...	1988	3149693
invasion and intracellular growth of rickettsia tsutsugamushi.	intracellular multiplication of rickettsia tsutsugamushi, a causative agent of scrub typhus, was examined by electron microscopy of specimens prepared at various time intervals after infection of in vitro cultured cells. the sequential morphological growth cycle of the microorganism is presented diagrammatically.	1988	3152710
antigenic and genetic relatedness of eight rickettsia tsutsugamushi antigens.	the genetic and antigenic relatedness of eight antigens in three strains of rickettsia tsutsugamushi has been studied by using recombinant organisms expressing epitopes of the 150-, 110-, 72-, 58-, 56-, 49-, 47-, and 20-kilodalton (kda) polypeptide antigens of the karp strain. southern blot analysis of karp, kato, and gilliam strain genomic dna by using probes specific for each antigen class indicated that while strong homology exists between each of the corresponding antigen genes in these thre ...	1989	2476399
purification and partial characterization of a type-specific antigen of rickettsia tsutsugamushi.	a type-specific antigen (54- to 56-kilodalton polypeptide) in the envelope of rickettsia tsutsugamushi was purified from each of three prototype strains (gilliam, karp, and kato) by a combination of mild anionic detergent treatment, gel filtration, and reverse-phase high-performance liquid chromatography. the purified antigens from the three strains were shown to have similar amino acid compositions: primarily aspartic acid, glutamic acid, and glycine, with lesser amounts of cysteine, methionine ...	1989	2496028
characterization of factors determining rickettsia tsutsugamushi pathogenicity for mice.	pathogenicity of rickettsia tsutsugamushi for laboratory mice is known to be influenced by at least three factors: (i) route of inoculation, (ii) antigenic strain, and (iii) natural resistance of the host. by using karp, gilliam, and kato strains of r. tsutsugamushi, we examined the effect of these three pathogenicity factors on the kinetics of infection and the development of immunity in balb/cdub and c3h/hedub mice. the appearance of rickettsemia in the pathogenic infections generally preceded ...	1989	2496030