| persistence of drug-resistant malaria parasites. | mixtures of drug-resistant and sensitive forms of plasmodium chabaudi were used to infect mice, and the resulting infections were maintained in the absence of drug. both chloroquine-resistant and pyrimethamine-resistant mutans were able to survive in such mixed infections. the results of experiments on chloroquine resistance indicated an apparent selective advantage of the resistant over the sensitive form. | 1978 | 74609 |
| plasmodium chabaudi-infection of mice: specific activities of erythrocyte membrane-associated enzymes and patterns of proteins and glycoproteins of erythrocyte membrane preparations. | membrane preparations of erythrocytes from normal and p. chabaudi-infected mice and membrane preparations of p. chabaudi-infected and uninfected erythrocytes from infected mice and separated by zonal centrifugation were characterized by the pattern of proteins and extracted glycoproteins obtained by sds-polyacrylamide gel electrophoresis and by the specific activities of membrane associated enzymes. the protein pattern of the membrane preparation of infected erythrocytes showed similar differenc ... | 1977 | 193221 |
| isolation of malaria merozoites: release of plasmodium chabaudi merozoites from schizonts bound to immobilized concanavalin a. | the ability of concanavalin a to bind erythrocytes but not malarial parasites was used for the development of a method of merozoite isolation: cells from infected blood were allowed to bind to a column of concanavalin a linked to sepharose beads and merozoites naturally released by maturation of the schizonts bound to the gel were collected. the principle of this method allows its application to several plasmodium species. the kinetics of merozoite production and the quality of the preparations ... | 1978 | 283417 |
| purification of intracellular forms of plasmodium chabaudi and their interactions with the erythrocyte membrane and with serum albumin. | a procedure using bovine serum albumin gradients was developed for the separation of p. chabaudi-infected mouse erythrocytes from uninfected cells. this procedure can be used for the purification of erythrocytes containing different developmental stages of the parasite. the purified parasites were able to synthesize in vitro all the proteins that they are capable of synthesizing in vivo. the intracellular forms of p. chabaudi were found to be associated with erythrocyte membrane components and t ... | 1977 | 303951 |
| interactions of rodent malarial parasites with friend erythroleukemia cells in vitro. | the ability of plasmodium chabaudi and p. yoelii to bind to friend erythroleukemia cells in vitro was examined. extensive binding of p. yoelii and weaker binding of p. chabaudi was observed. binding to mouse fibroblasts was not seen, although there was some binding to cells of a mouse mastocytoma. the binding of p. yoelii to friend cells was sensitive to specific antiserum. the development of p. berghei and p. yoelii in friend cells was followed by microscopic examination and measurement of the ... | 1977 | 303954 |
| plasmodium chabaudi in mice. adoptive transfer of immunity with enriched populations of spleen t and b lymphocytes. | thymectomized nih and c57bl mice were more susceptible to plasmodium chabaudi than controls, indicating a role for t cells in acquired immunity to the parasite. enriched populations of t and b cells were prepared from the spleens of immune mice using nylon-wool columns, and were adoptively transferred to syngeneic non-irradiated mice or mice irradiated with 600 or 800 rad. some immunity could usually be transferred with immune t, b and glass-wool (g.w.) filtered spleen cell populations. in the h ... | 1978 | 306962 |
| malaria infections in different strains of mice and their correlation with natural killer activity. | different mouse strains show marked variation in susceptibility to murine malaria parasites. of those studied, strain a mice showed the highest susceptibility, most animals dying from plasmodium chabaudi infections. in contrast, c57bl and cba mice all recovered from p. chabaudi infections and were then resistant to challenge with a virulent strain of p. yoelii. balb/c mice recovered from p. chabaudi infections but were not uniformly resistant to p. yoelii challenge. b10.a mice, which share haplo ... | 1979 | 317441 |
| [malaria plasmodia in the mouse. parasitization of mature and immature erythrocytes by plasmodium berghei, plasmodium yoelii and plasmodium chabaudi (author's transl)]. | plasmodium berghei parasites (strain k173) in mice with developing immunity changed to a variant type with increased resistance against antibodies and enhanced invasion of mature erythrocytes; on passages in normal mice this variant type retransformed to the normal type (kretschmar 1964). on detailed study, parasites of the variant type showed a markedly decreased predilection for polychromatophilic erythrocytes, leading to slowed multiplication during prepatency, increased invasion of mature er ... | 1979 | 384629 |
| glutamate dehydrogenase and aspartate aminotransferase in trypanosoma cruzi. | 1. the cultured, epimastigote-form of trypanosoma cruzi contains nadp-linked glutamate dehydrogenase (ec 1.4.1.4), with a molecular weight of about 280,000, similar to the enzyme from plasmodium chabaudi and different from the enzymes from higher animal sources. 2. t. cruzi also contains aspartate aminotransferase (ec 2.6.1.1), with properties similar to those of the enzyme from mammals. 3. the concerted action of the transaminase and glutamate dehydrogenase might be responsible for the producti ... | 1977 | 400947 |
| antibody to fibrinogen/fibrin products (anti-f) in malaria, babesiosis, and trypanosomiasis of rodents. | antibody to fibrinogen/fibrin related products (anti-f) was stimulated during the course of plasmodium chabaudi, babesia rodhaini, and trypanosoma lewisi infections in rats. titers of this autoantibody remained elevated in serum from rats that had recovered from each of the infections. column chromatographic studies indicated that anti-f was a 19s globulin, possibly igm. during acute infections high titers of anti-f were associated with elevated titers of cold-active hemagglutinin (cah) and immu ... | 1979 | 480072 |
| [plasmodium chabaudi: changes in the surface sialic acids of red blood cells during infection (author's transl)]. | surface sialic acids of mice red blood cells infected with the malarial parasite plasmodium chabaudi are increased as compared to extracts of red cells from normal mice. this increase occurs coincidentally when reticulocytes increase in the peripheral blood. the same increase of surface sialic acids is shown by studies of reticulocytes from phenylhydrazine treated mice. similarly, neutral hexoses, fucose, were found in greater quantities in surface glycopeptides obtained after incubation with tr ... | 1979 | 485035 |
| experimental infection with plasmodium chabaudi in rats: antigen and antibody associated with anemia and glomerulonephritis of acute infection. | rat-adapted plasmodium chabaudi caused a syndrome characterized by hemolytic anemia, splenomegaly, and glomerulonephritis. all rats recovered and appeared normal after 4 weeks despite persistence of proteinuria. serologic studies on the malarious rats revealed that the infection was associated with a soluble antigen which was present concurrently with antibody in plasma, in material eluted from blood cells, in extracts of kidney tissues, and in the urine. this antigen appeared to be identical wi ... | 1977 | 592039 |
| increase in non-specific antibody mediated cytotoxicity in malarious mice. | the k cell activity in the spleens of mice infected with plasmodium chabaudi has been investigated. chicken red cells coated with antibody were the target cells used. increased k cell activity was found 6 to 15 days, but not 3 days, after infection with the malaria parasites. | 1978 | 737899 |
| malaria parasites of rodents of the congo (brazzaville): plasmodium chabaudi adami subsp. nov. and plasmodium vinckei lentum landau, michel, adam and boulard, 1970. | descriptions are given of the blood forms, sporogonic stages and enzyme forms of plasmodium chabaudi adami subsp.-nov. and p. vinckei lentum, malaria parasites of the thicket-rat thamnomys rutilans of the brazzaville region. the two species differ from each other in both morphological and enzymic characters. p.c. adami and p. v. lentum differ from the other subspecies of p. chabaudi and p. vinckei principally by their enzyme forms. | 1976 | 800328 |
| plasmodium chabaudi: host lymphocyte-macrophage interaction in vitro. | | 1977 | 862706 |
| experimental infection with plasmodium chabaudi in rats. observations on adaptation and the immune responses to infection. | plasmodium chabaudi was adapted to rats after some initial refractoriness. progressive adaptation was indicated by shortening of the prepatent period and increases in peak parasitemia with successive passages. rats infected with parasites of early passages resisted the infection, and even splenectomized rats quickly recovered. however, the parasites appeared to become more virulent with successive passages and after the 45th passage, all adult rats inoculated with the parasite died with severe h ... | 1977 | 864563 |
| genetic studies on plasmodium chabaudi: recombination between enzyme markers. | two lines of plasmodium chabaudi differing in three characters have been crossed, using a technique previously described for p. yoelii. one line, termed 47as, was characterized by an electrophoretic form of 6-hosphogluconate dehydrogenase, denoted 6pgd-2, a form of lactate dehydrogenase, denoted ldh-3, and was pyrimethanime-resistant. the second line, termed 10aj, possessed enzyme forms of 6pgd-3 and ldh-2 and was pyrimethamine-sensitive. the cross was made by permitting mosquitoes to feed on a ... | 1975 | 1118185 |
| new observations on the malaria parasites of rodents of the central african republic - plasmodium vinckei petteri subsp. nov. and plasmodium chabaudi landau, 1965. | the morphology and enzyme forms of malaria parasites isolated from 50 wild caught specimens of thamnomys rutilans from the central african republic have been studied and three distinct species of plasmodium identified. one species has been confirmed as plasmodium yoelii yoelii. morphological features of both the remaining species correspond to those given by landau (1965) in her original description of plasmodium chabaudi. for one of these species the name p. chabaudi has been retained; the othe ... | 1975 | 1155987 |
| macrophage activation during plasmodium chabaudi as infection in resistant c57bl/6 and susceptible a/j mice. | macrophage activation was examined in resistant c57bl/6 and susceptible a/j mice during the course of blood-stage infection with plasmodium chabaudi as. three parameters of macrophage activation (lipopolysaccharide [lps]- and malaria antigen-induced tumor necrosis factor [tnf] production in vitro, phorbol myristate acetate [pma]-induced production of oxygen metabolites in vitro, and ia antigen expression) were assessed during infection in populations of peritoneal and splenic macrophages recover ... | 1992 | 1311705 |
| plasmodium falciparum and plasmodium chabaudi: characterization of glycosylphosphatidylinositol-degrading activities. | merozoites of malaria parasites have a membrane-bound serine protease whose solubilization and subsequent activity depend on a parasite-derived glycosylphosphatidylinositol-phospholipase c (gpi-plc). the gpi-degrading activities from both plasmodium falciparum and plasmodium chabaudi have been characterized and partially purified by phenylboronate chromatography. they are membrane-bound, developmentally regulated, calcium-independent enzymes and as such they resemble gpi-plc of trypanosoma bruce ... | 1992 | 1317298 |
| functional characterization of protective cd4+ t-cell clones reactive to the murine malaria parasite plasmodium chabaudi. | protective immunity to asexual malaria parasites appears to be mediated predominantly by the cd4+ subset of t lymphocytes. to examine the role of this t-cell population in the immune response to the murine malaria parasite plasmodium chabaudi, cd4+ clones derived from infected mice were raised and propagated in vitro. analysis of the reactivity of clones responsive to parasite antigen demonstrated that the cd4+ cell response is heterogeneous and is consistent with the idea of two functionally di ... | 1992 | 1356918 |
| identification and quantification of rodent malaria strains and species using gene probes. | a dna probe pcsv4 and a subclone thereof pcsv4.1, hybridize specifically to rodent malaria dna. dna purified from a small volume (10 microliters) of infected mouse blood was used to determine the composition of the parasite population present. the hybridization signal following pcsv4 probing of slot-blotted dna correlated directly with parasitaemia. the hybridization pattern and intensity, resulting from probing restriction enzyme digested and southern-blotted genomic dna, determined the identit ... | 1992 | 1359498 |
| structure and expression of the gene for pv200, a major blood-stage surface antigen of plasmodium vivax. | molecular cloning and structure analysis of the gene encoding the pv200 protein of the sal-1 strain of plasmodium vivax revealed an overall identity of 34-37% when the deduced amino acid sequence was compared with the sequences of various major merozoite surface antigens of plasmodium falciparum, plasmodium yoelii and plasmodium chabaudi. when the sal-1 pv200 sequence was compared with the corresponding sequence from the belèm strain of p. vivax, it was found that the two merozoite surface antig ... | 1992 | 1371329 |
| cell cycle analysis of asexual stages of erythrocytic malaria parasites. | intra-erythrocytic plasmodium species can be stained with the dna binding dye, hoechst 33342, and the distribution of dna content determined for parasite populations by flow cytometric measurement of fluorescence. analysis of this distribution will determine the parasitaemia (percentage of erythrocytes infected), and the percentages of trophozoite infected red blood cells, polyparasitized (trophozoite) red blood cells, and schizont/segmenter infected red blood cells. this analysis is based on th ... | 1992 | 1391230 |
| plasmodium chabaudi p68 serine protease activity required for merozoite entry into mouse erythrocytes. | to define the role of malaria parasite enzymes during the process of erythrocyte invasion, we have developed an in vitro serum-free invasion assay of mouse erythrocytes by purified plasmodium chabaudi merozoites. the sensitivity of a merozoite-specific serine protease (p68) to various inhibitors and the effect of these inhibitors on invasion indicate a crucial role for p68. the substrate specificity of the purified enzyme has been partially defined using fluorogenic peptides. consistent with thi ... | 1992 | 1409678 |
| plasmodium chabaudi as: erythropoietic responses during infection in resistant and susceptible mice. | the course of anemia and the erythropoietic response in the bone marrow, spleen, and blood were studied during plasmodium chabaudi as infection in resistant c57bl/6 (b6) and susceptible a/j (a) mice. infections in b6 mice were characterized by moderate levels of both parasitemia and anemia and survival. in contrast, a mice experienced high parasitemia, severe anemia, and high mortality rates. during the period of anemia, erythropoiesis, as measured by in vivo 59fe incorporation, was significantl ... | 1992 | 1426136 |
| proteins with molecular masses of 25 to 40 kilodaltons elicit optimal protective responses against plasmodium chabaudi adami infection. | the presence of the cd4+ t cell has been shown to be crucial for resolution of acute infection in the plasmodium chabaudi adami murine malaria model. this model is, therefore, suitable for the isolation of malaria antigens that are capable of activating protective t cells. in light of this, we set out to identify p. chabaudi adami molecules that activate protective responses in this model. denatured p. chabaudi adami proteins were isolated by continuous-flow electrophoresis on the basis of their ... | 1992 | 1452338 |
| plasmodium berghei and plasmodium chabaudi chabaudi: development of simple in vitro erythrocyte invasion assays. | erythrocyte invasion assays are described for two species of rodent malaria, namely plasmodium berghei and p.c. chabaudi. these invasion assays are simple, are carried out using a candle jar and allow a number of assays to be performed simultaneously. our results demonstrate that both rodent malaria species show an in vitro preference for reticulocytes although the preference of p. c. chabaudi for these cells is not as marked as that of p. berghei. the details of our invasion assays and our resu ... | 1992 | 1461676 |
| assessment of parasite population dynamics in mixed infections of rodent plasmodia. | cloned lines of the four rodent plasmodium species can be differentiated by the rflp pattern generated following southern blotting and probing with pcsv4.1, a probe derived from a p. chabaudi chabaudi genomic library. groups of cba/ca mice were inoculated simultaneously with cloned lines from two parasite species or strains. six mixed species and three mixed strain infections using rodent malaria lines were initiated. the composition of the parasite population in each group was determined qualit ... | 1992 | 1461677 |
| structure of a plasmodium chabaudi acidic phosphoprotein that is associated with the host erythrocyte membrane. | we have characterized by molecular cloning and sequencing a plasmodium chabaudi antigen that is associated with the membrane of the infected erythrocyte throughout the entire intraerythrocytic cycle. the protein (pcema1) has a predicted size of 50 kda and contains a major tandem repeat array of 16 octapeptides that constitutes almost 30% of the protein. at its amino-terminus, pcema1 has a string of hydrophobic residues characteristic of a secreted protein, but does not contain a hydrophobic memb ... | 1992 | 1475002 |
| testosterone-induced suppression of self-healing plasmodium chabaudi malaria: an effect not mediated by androgen receptors? | this study investigates whether androgen receptors (ar) mediate the suppressive effect of testosterone on self-healing plasmodium chabaudi malaria. our data show the following. (1) female and castrated male mice of the inbred strain c57bl/10 self-heal and survive infections when challenged with 10(6) p. chabaudi-parasitized erythrocytes. however, self-healing is prevented when circulating testosterone levels are high as in intact males or in females and castrated males pretreated with 0.9 mg tes ... | 1992 | 1487694 |
| plasmodium chabaudi: estradiol suppresses acquiring, but not once-acquired immunity. | this study investigates the effect of estradiol (e) on self-healing of plasmodium chabaudi malaria in mice of the inbred strain c57bl/10. our data show: (1) female mice and male castrates are capable of self-healing infections when challenged with 10(6) p. chabaudi-infected erythrocytes. self-healing is completely suppressed after pretreatment of mice with 12 micrograms e injected sc twice a week for 3 weeks. (2) the suppressive effect of e is prevented by the estrogen receptor blockers tamoxife ... | 1992 | 1516672 |
| plasmodium chabaudi and trypanosoma cruzi infections can reverse igg2ab chronic suppression in mice. | the effects of infections with plasmodium chabaudi or trypanosoma cruzi on chronic cd8+ t cell dependent igg2ab suppression were analyzed in homozygous ighb/b adult mice. these parasites are known to induce a cd4+ t cell dependent polyclonal activation characterized in particular by a considerable increase in igg2a expression. we report here that infection with either parasite reversed the igg2ab suppression in 18 out of 32 mice. however, in mice treated with anti-cd4 mab in parallel to the para ... | 1992 | 1567793 |
| rapid transport of the acidic phosphoproteins of plasmodium berghei and p. chabaudi from the intraerythrocytic parasite to the host membrane using a miniaturized fractionation procedure. | a miniaturized procedure for the separation of the host erythrocyte membrane from malarial parasites based on saponin lysis and density-gradient centrifugation with percoll is described. the procedure requires only 20-35 microliters packed infected erythrocytes, is simple to perform, needs no sophisticated equipment, and can be completed in less than 2 h. analysis of the isolated erythrocyte membranes and parasites using marker enzymes and electron microscopy revealed that both the purity and th ... | 1992 | 1589427 |
| testosterone-unresponsiveness of existing immunity against plasmodium chabaudi malaria. | testosterone (te) is known to suppress immunity and to increase host susceptibility to many parasites. this study investigates the action of te on immunity acquired against blood-stages of the malaria parasite plasmodium chabaudi in female mice of the inbred strain c57bl/10. our data show: (i) about 90% of mice infected with 10(6) p. chabaudi-infected erythrocytes are able to develop protective immune mechanisms which become evident in self-healing the infection. the capability of self-healing i ... | 1992 | 1625907 |
| testosterone-induced diminution of two peptides in spleen cells from testosterone-immunosuppressed b10 mice. | high-performance liquid chromatography (hplc) is used to detect testosterone (t)-sensitive peptides in spleen cells isolated from female c57bl/10 mice immunosuppressed against plasmodium chabaudi malaria by t treatment. two peaks with retention times of about 25 min and 34 min, respectively, were identified to be diminished by about 52% and 47%, respectively, in spleen cells from t-treated mice compared to those from untreated mice. amino acid sequencing revealed that the 24 min peak consisted o ... | 1992 | 1639211 |
| production of superoxide by macrophages from plasmodium chabaudi infected mice. | in vitro superoxide production by spleen and peritoneal macrophages was assessed as a function of plasmodium chabaudi infection in the mouse. within the first 5 days post-infection, as parasitaemia rose, there was an increase in phorbolmyristate acetate-triggered superoxide generation by the spleen macrophages. the ability of the macrophages to produce o2- began to decline as the parasite burden increased and at peak it fell to control (pre-infection) levels. this refractory period may have resu ... | 1991 | 1651216 |
| cd4+ t cells and b cells are necessary for the transfer of protective immunity to plasmodium chabaudi chabaudi. | it is shown here that b cells, in addition to cd4+ t cells, are necessary for the development of protective immunity to plasmodium chabaudi chabaudi (p. chabaudi) in mice. reconstitution of severe combined immunodeficient (scid) mice with immune or normal cd4+ t cells protected the majority of mice against an otherwise lethal challenge but the mice were unable to clear their parasitemias. by contrast, transfer of the same t cell populations into athymic nu/nu mice enabled the recipients to contr ... | 1991 | 1675172 |
| plasmodium chabaudi: polymorphic and nonpolymorphic epitopes of the antigen pch105/resa. | the localization in the erythrocyte membrane of pch105/resa, the ring stage-infected erythrocyte surface antigen of plasmodium chabaudi, the proposed analog to the vaccine candidate pf155/resa in p. falciparum, is here confirmed by the use of the immunogold technique in electron microscopy. furthermore, a number of monoclonal antibodies to other p. chabaudi erythrocyte membrane antigens in the same molecular weight range as pch105 were compared in different test systems. data from immunoblotting ... | 1990 | 1691108 |
| the epitope of a protective monoclonal antibody occurs in a region of microheterogeneity in plasmodium chabaudi. | | 1990 | 1700297 |
| in vivo effects of anti-idiotype on plasmodium chabaudi infection in mice. | a polyclonal anti-idiotype was raised in rabbits following immunization with a murine monoclonal antibody which recognized a 250,000 mw antigen of plasmodium chabaudi-infected erythrocytes. the monoclonal antibody, nimp m23 (clone 3,) has been shown to protect mice against homologous parasite challenge. following purification, the anti-idiotype was shown to bind only the immunizing idiotype and to recognize antigen-binding site-associated anti-idiotype. mice primed with anti-idiotype and challen ... | 1991 | 1718854 |
| t-cell-dependent immunity and thrombocytopenia in rats infected with plasmodium chabaudi. | normal, splenectomized, and athymic fischer rats were infected with plasmodium chabaudi. in normal rat infections, acute-phase infection resolved rapidly and completely. in splenectomized rats, infection resulted in high parasitemia and ultimately death. in nude rats, parasite growth was reduced compared with normal rats, and a persistent parasitemia (between 20 and 45%) was observed for several months. complete resolution of the infection was achieved after adoptive transfer of t lymphocytes, e ... | 1992 | 1729178 |
| plasmodium chabaudi: association of reversal of chloroquine resistance with increased accumulation of chloroquine in resistant parasites. | the effects of tricyclic antidepressants, desipramine and imipramine, and phenothiazines, chlorpromazine and trifluoperazine, on chloroquine (cq)-resistant and cq-sensitive lines of p. chabaudi were examined in vivo. in mice that received daily injections of these drugs the growth of cq-resistant and cq-sensitive parasites was unaffected or affected very slightly, if at all. a combination of cq and each drug suppressed the growth of cq-resistant parasites in a dose-dependent manner. in addition, ... | 1992 | 1740175 |
| ultrastructural changes associated with reversal of chloroquine resistance by verapamil in plasmodium chabaudi. | reversal of chloroquine (cq) resistance by verapamil, a ca2+ antagonist, has been shown in cq-resistant human and rodent malaria parasites. here, we report ultrastructural changes associated with this phenomenon in cq-resistant plasmodium chabaudi (as strain) after infected mice were administered cq and verapamil. at parasitaemias of 5-7%, cq at 6 mg/kg caused little morphological effect on cq-resistant parasites. in contrast, co-administration of cq and verapamil at 50 mg/kg induced swelling of ... | 1991 | 1745546 |
| clonal analysis of b lymphocyte responses to plasmodium chabaudi infection of normal and immunoprotected mice. | parasite infection causes marked perturbations in the host immune system, as shown by hypergammaglobulinemia, autoimmunity and immune depression, but there is little information on the number, specificities and performance of b cell clones activated in the course of infection. we have addressed these questions in a model of murine malaria induced by plasmodium chabaudi, where primary infection results in very marked b cell responses that shift in ig isotype pattern in immunoprotected animals, an ... | 1991 | 1777417 |
| amplification of a cryptosporidium parvum gene fragment encoding thymidylate synthase. | currently, there is no effective therapy for cryptosporidiosis and it is unclear why antifolate drugs which are effective treatments for infections caused by closely related parasites are not also effective against cryptosporidium parvum. in protozoa, the target of these drugs, dihydrofolate reductase (dhfr), exists as a bifunctional enzyme also manifesting thymidylate synthase (ts) activity and is encoded by a fused dhfr-ts gene. in order to prepare a probe to isolate the c. parvum dhfr-ts gene ... | 1991 | 1818199 |
| testosterone-induced susceptibility to plasmodium chabaudi malaria: variant protein expression in functionally changed splenic non-t cells. | this study investigates the effects of the male sex hormone, testosterone (te), on self-healing of plasmodium chabaudi malaria as well as on protein expression and functional properties of total spleen cells and splenic t cells in females of the mouse strain c57bl/10. about 90% of the b10 females survive a challenge with 10(6) p. chabaudi-infected erythrocytes. the percentage of self-healers, however, is reduced to about 60%, 40%, and 0% after pretreatment with te for 1, 2, and 3 weeks, respecti ... | 1991 | 1820973 |
| screening cdna expression libraries in lambda gt11 with a t cell hybridoma. | a t cell hybridoma specific for a protein of plasmodium chabaudi chabaudi has been used to test a system for direct t cell screening of a cdna library of p. chabaudi in the phage lambda gt11. the technique is based upon the rapid separation of the recombinant beta-galactosidase fusion protein from the bacterial mixtures using polystyrene beads coated with anti-beta-galactosidase antibodies. these coated beads are cultured with antigen-presenting cells and the t cell hybridoma. the technique is s ... | 1991 | 1828474 |
| resistance to malaria in ankyrin and spectrin deficient mice. | inbred mice carrying mutations in ankyrin and/or spectrin synthesis and assembly were studied for their ability to support the growth of the rodent malarias, plasmodium chabaudi adami and p. berghei, in vivo. mice carrying the nb/nb (normoblastosis) mutation which do not synthesize ankyrin and therefore also have a deficiency in membrane-bound spectrin, were refractory to p. chabaudi adami, which invades mature erythrocytes and to p. berghei, which invades reticulocytes. similarly, sph/sph mice ... | 1991 | 1832936 |
| comparative and sequential histopathology of plasmodium chabaudi-infected balb/c mice. | 1. rodent experimental models have been useful to study severe malaria but few serial and controlled studies have been conducted. in the present investigation, we describe the histopathology of lethal and non-lethal rodent malaria induced by plasmodium berghei and p. chabaudi. p. berghei malaria shows a uniformly lethal course, while p. chabaudi malaria produces a non-lethal acute infection with recovery and periodical recrudescences. sequential histopathological changes were also characterized ... | 1991 | 1843871 |
| cd4+ and cd8+ t lymphocytes both contribute to acquired immunity to blood-stage plasmodium chabaudi as. | in the present study, the contribution of cd4+ and cd8+ t lymphocytes to acquired immunity to blood-stage infection with the murine malaria species plasmodium chabaudi as was investigated. c57bl/6 mice, which are genetically resistant to infection with this hemoprotozoan parasite and exhibit a transient course of infection, were treated intraperitoneally with monoclonal antibodies to t-cell epitopes, either anti-thy-1, anti-cd4, or anti-cd8. after intraperitoneal infection with 10(6) parasitized ... | 1991 | 1898902 |
| differential t cell responses to plasmodium chabaudi chabaudi in peripheral blood and spleens of c57bl/6 mice during infection. | the definition of the immune status of a person is often taken as the responses obtained from lymphocytes isolated from peripheral blood. we therefore analyzed in a mouse model of plasmodium chabaudi chabaudi the response of t lymphocytes taken from peripheral blood and compared it with the spleen during and after a primary erythrocytic infection. using limiting dilution conditions, no malaria-specific t cell responses could be measured in the peripheral blood for up to 21 days after infection w ... | 1991 | 1901884 |
| cd4+t cell-dependent effector mechanisms important in the immune response to the erythrocytic stages of plasmodium chabaudi chabaudi (as). | the ability to produce ifn-gamma during an erythrocytic infection with p. chabaudi chabaudi is not an indicator of resistance or susceptibility of mice to this infection. however, ifn-gamma may play a transient role in immune control of the parasite. we have shown that after its removal in vivo by antibody treatment the acute phase of infection is clearly exacerbated. after the acute phase of infection the t cell response changes from one characterized by ifn-gamma production to one of a t helpe ... | 1991 | 1904712 |
| gamma interferon production in endotoxin-responder and -nonresponder mice during infection. | the production of gamma interferon (ifn-gamma) in response to infection and to a number of other agents was compared in lpsn (c3h/hen and c57bl/10scsn) and lpsd (c3h/hej and c57bl/10sccr) mouse strains. large differences in ifn-gamma production were observed between c57bl/10sccr mice and the other mouse strains. with the exception of c57bl/10sccr, all mouse strains, including c3h/hej, exhibited transient levels of ifn-gamma during infection with salmonella typhimurium. spleen cells of these mice ... | 1991 | 1910003 |
| analysis of msa-1 diversity in plasmodium chabaudi chabaudi strains. | | 1991 | 1922203 |
| testosterone and other gonadal factor(s) restrict the efficacy of genes controlling resistance to plasmodium chabaudi malaria. | the effect of circulating concentrations of testosterone (te) on resistance to plasmodium chabaudi malaria was investigated in the h-2 congenic mouse strains c57bl/10, b10.a, b10.a(3r), b10.a(4r), and b10.d2. te-levels were determined by radioimmunoassay and resistance was expressed in terms of percent self-healers after challenge with 10(6) p. chabaudi-infected erythrocytes. our data indicate: (i) females and castrated males reveal very similar interstrain variations of resistance. these do not ... | 1991 | 1923561 |
| genetic studies on a major merozoite surface antigen of the malaria parasite of rodents, plasmodium chabaudi. | diversity in a major merozoite surface antigen (msa-1) of plasmodium chabaudi has been examined using a panel of monoclonal antibodies (moabs). the antigen was found to be different in each of twelve cloned isolates, as shown by its reactivity with the moabs in immunofluorescence tests. in genetic crossing experiments, the diverse forms of this antigen were shown to be determined by allelic variation of a single gene. recombination occurred between the msa-1 gene, a second blood stage antigen an ... | 1991 | 1923562 |
| testosterone-induced abrogation of self-healing of plasmodium chabaudi malaria in b10 mice: mediation by spleen cells. | this study investigates the suppressive effect of testosterone (te) on the self-healing of plasmodium chabaudi malaria in female mice of the strain c57bl/10, and, in particular, the possible role of spleen cells in mediating this te effect. our data show the following. (i) about 80% of b10 mice infected with 10(6) p. chabaudi-infected erythrocytes are capable of self-healing the infections. this capability is progressively impaired and finally abrogated after pretreating the b10 mice with te for ... | 1991 | 1937807 |
| role of gamma interferon during infection with plasmodium chabaudi chabaudi. | a role has been proposed for inflammatory mediators such as gamma interferon (ifn-gamma) and reactive oxygen intermediates in the control of the blood stages of plasmodium organisms. it was previously shown that ifn-gamma can be detected in the plasma of mice with a primary infection by plasmodium chabaudi chabaudi (as). we found that susceptible and other resistant mouse strains produced ifn-gamma, suggesting that susceptibility is not due to a defect in ifn-gamma production. administration of ... | 1990 | 1977706 |
| the role of cd4+ t cells in the protective immune response to plasmodium chabaudi in vivo. | cd4+ t cells are an essential component of the protective immune response to plasmodium chabaudi. in order to determine whether the presence of cd4+ t cells is necessary throughout a primary infection for a protective immune response to develop mice were depleted of their cd4+ t cells in vivo by treatment with specific antibodies. removal of cd4+ t cells during the acute phase of infection renders mice incapable of clearing their infection. in contrast, removal of cd4+ t cells after this time di ... | 1990 | 1980906 |
| induction of high levels of igg autoantibodies in mice infected with plasmodium chabaudi. | this study analyzed the effect of infection of mice with a virulent strain of plasmodium chabaudi on natural autoantibodies. mice received appropriate treatments in order to survive and the serum autoantibodies were characterized either by enzyme immunoassays against a panel of self and non-self antigens or by western immunoblots using fibroblast or red blood cell (rbc) extracts. igm and mainly igg antibodies directed against actin, myoglobin, myosin, spectrin, tubulin, and trinitrophenylated-ov ... | 1991 | 2049335 |
| distinct lipid compositions of parasite and host cell plasma membranes from plasmodium chabaudi-infected erythrocytes. | mouse erythrocytes infected with early or late trophozoites of the malaria parasite plasmodium chabaudi were fractionated into free parasites and host cell plasma membranes, and both fractions were analyzed for cholesterol content and the composition of phospholipids and total fatty acids. the major results are: (i) parasites contain only a very low level of cholesterol which is about one-tenth of that of host cell plasma membranes. (ii) parasites also contain less sphingomyelin and phosphatidyl ... | 1991 | 2052027 |
| production of soluble inhibitor of erythropoiesis during plasmodium chabaudi as infection in resistant and susceptible mice. | | 1991 | 2069308 |
| molecular cloning and sequence analysis of the gene encoding the major merozoite surface antigen of plasmodium chabaudi chabaudi ip-pc1. | the complete nucleotide sequence of the gene encoding the precursor to the major merozoite surface antigens of plasmodium chabaudi chabaudi strain ip-pc1 has been determined. a single open reading frame was detected, that coded for a protein of 199 kda. the encoded protein (p199) contains putative signal and membrane anchor sequences and shows a clustering of cys residues in the last 120 amino acids. incompletely conserved tandem repeat oligopeptides are present at different positions in the mol ... | 1990 | 2090945 |
| the inhibition of plasmodium falciparum growth in vitro by sera from mice infected with malaria or treated with tnf. | despite some years of enquiry, the mechanism that leads to intra-erythrocytic death of malarial parasites during the host's response to infection has not been elucidated. we report here that serum from mice undergoing a successful immune response to plasmodium chabaudi does not inhibit plasmodium falciparum unless the pl. chabaudi is virulent enough to rise to at least 50% parasitaemia and to cause illness. this appears to be true of the 556 ka and ds strains of pl. chabaudi, and also other muri ... | 1990 | 2092288 |
| dependence on cell-mediated mechanisms for the appearance of crisis forms during plasmodium chabaudi as infection in c57bl/6 mice. | the appearance of crisis forms or degenerate, intraerythrocytic parasites in the peripheral blood of c57bl/6 hosts during the course of plasmodium chabaudi as infection was analysed. following intraperitoneal injection with 10(6) parasitized erythrocytes, c57bl/6 hosts, which are resistant to this species of rodent plasmodium, eliminate the parasite from the peripheral blood by 4 weeks and recover from acute infection. elimination of the parasite coincides with the appearance in the peripheral b ... | 1990 | 2099383 |
| role of endogenous gamma interferon in host response to infection with blood-stage plasmodium chabaudi as. | the role of gamma interferon (ifn-gamma), a pluripotent lymphokine capable of activating macrophages, in acquired immunity to blood-stage malaria was investigated. c57bl-derived, lipopolysaccharide-resistant c57bl/10scn mice, which were found to be resistant to intraperitoneal (i.p.) infection with 10(6) plasmodium chabaudi as parasitized erythrocytes, were treated with monoclonal anti-ifn-gamma antibody (mab). two mabs were used: r4-6a2, a rat anti-mouse, neutralizing immunoglobulin g1, which w ... | 1990 | 2119342 |
| role of interferon-gamma and tumor necrosis factor in host resistance to plasmodium chabaudi as. | the contribution of the t cell- and macrophage-derived cytokines, interferon-gamma (ifn-gamma) and tumor necrosis factor (tnf), respectively, in the cell-mediated mechanisms leading to acquired immunity to blood-stage plasmodium chabaudi as was investigated. to examine the contribution of ifn-gamma, resistant c57bl-derived mice were treated during infection with two different neutralizing, anti-murine ifn-gamma mabs. such treatment impaired the ability of the host to limit parasite multiplicatio ... | 1990 | 2126523 |
| the adoptive transfer of t-cell dependent immunity to plasmodium chabaudi chabaudi in cba/ca mice is achieved only after superinfection of immune spleen cell donors. | the transfer of spleen cells from cba/ca mice recovered from a p. c. chabaudi as primary infection into irradiated syngeneic recipients conferred very poor protection. neither elimination of ly2 cells from immune spleen cells nor reinfection of the donors some days before transfer improved protection significantly. significant protection was transferred with spleen cells from donors which had been infected 7 times prior to cell transfer. transferred protection was reduced or eliminated by pretre ... | 1990 | 2143571 |
| cytokine production in lethal and non-lethal murine malaria. | levels of ifn-gamma, il-2 and il-4 were measured in vitro during the course of non-lethal plasmodium chabaudi adami and lethal p. chabaudi strain 1309 infections in balb/cbyj mice. spleen cells from mice infected with the non-lethal plasmodium had a higher initial response to p. chabaudi antigens than mice infected with p. chabaudi strain 1309, as determined by measuring all three lymphokines. we conclude that both th1 and th2 subsets of t helper lymphocytes are activated during p. chabaudi adam ... | 1990 | 2149359 |
| passive immunization against plasmodium chabaudi malaria with pch 21 merozoite monoclonal antibody. | | 1990 | 2191289 |
| chromosomal rearrangements and point mutations in the dhfr-ts gene of plasmodium chabaudi under antifolate selection. | selection of the rodent malaria plasmodium chabaudi with low levels of the antifolate drug pyrimethamine has previously been shown by us to result in duplication of the dihydrofolate reductase-thymidylate synthase (dhfr-ts) gene by a duplication of chromosome 7 and subsequent rearrangements. we have selected this resultant parasite line with large doses of pyrimethamine and analysed the dhfr-ts gene and chromosomes for any changes. increased drug pressure has resulted in reappearance of a chromo ... | 1990 | 2233898 |
| tnf and inhibition of growth of plasmodium falciparum. | the mechanism of intra-erythrocyte death of plasmodium chabaudi in vivo has not yet been elucidated. here we summarise recent experiments in which serum from mice undergoing a successful immune response to this parasite did not inhibit plasmodium falciparum in vivo unless the p. chabaudi infection and tnf levels were high enough to cause illness in the host. this was true for the 556ka and ds strains of p. chabaudi in intact mice, but not for 556ka in nude mice, which did not generate inhibitory ... | 1990 | 2283147 |
| the parasitology of malaria and the study of protective immunity. | phenotypic antigenic variation within parasite strains and antigenic diversity between strains are important parameters in understanding the development of immunity to malaria. with the plasmodium chabaudi chabaudi model in inbred mice, a combination of serological tests and dna technology can be used to study the specificity of inducer and effector mechanisms in an infection with characteristics similar in many ways to those of p. falciparum in man. | 1990 | 2283164 |
| relationships between sequestration, antigenic variation and chronic parasitism in plasmodium chabaudi chabaudi--a rodent malaria model. | we describe here a rodent malaria model using cloned lines of plasmodium chabaudi chabaudi in inbred cba/ca mice that exhibits both clonal antigenic variation in late stage-specific surface antigens, and deep vascular schizogony in the liver. we show that both these features are modulated by the spleen, and that surface antigen expression is crucially involved in the sequestering phenotype. surface antigens are variant in chronic infection, and host protective immune responses can distinguish be ... | 1990 | 2314922 |
| early appearance of variant parasites in plasmodium chabaudi infections. | previous studies have shown that the recrudescence parasitaemias seen in mice infected with plasmodium chabaudi as strain are antigenically different from the infecting parent population. antigenic differences between recrudescent and parent populations were demonstrated in a passive transfer assay. in the present study, using the same assay system, it has been shown that in some mice, variant parasites (i.e. different from the parent population) can be detected at a time when the primary parasi ... | 1990 | 2320383 |
| plasmodium chabaudi: in vivo effects of ca2+ antagonists on chloroquine-resistant and chloroquine-sensitive parasites. | the effects of ca2+ antagonists, verapamil, nicardipine, and diltiazem, on susceptibility to chloroquine were examined in mice infected with chloroquine-sensitive and chloroquine-resistant lines of plasmodium chabaudi. in mice that received no chloroquine, daily injections of 50 mg/kg of verapamil, nicardipine, or diltiazem did not affect the growth of both sensitive and resistant parasites. when mice were injected daily with verapamil plus 2 to 3 mg/kg chloroquine, the chloroquine-sensitive par ... | 1990 | 2323395 |
| resolution of acute malarial infections by t cell-dependent non-antibody-mediated mechanisms of immunity. | while it is generally accepted that acute blood stage malarial infections are resolved through the actions of protective antibodies, we observed that resistance to acute infection with plasmodium chabaudi adami was mediated by t cell-dependent cellular immune mechanisms independent of antibody. we now report that acute blood stage infections caused by three additional murine hemoprotozoan parasites, plasmodium vinckei petteri, plasmodium chabaudi chabaudi, and babesia microti, appear to be contr ... | 1990 | 2387628 |
| a second region recognized by the protective monoclonal antibody 5c10/66 in the precursor to the major merozoite surface antigen of plasmodium chabaudi adami. | | 1990 | 2398918 |
| antigen-specific, interleukin 2-propagated t lymphocytes confer resistance to a murine malarial parasite, plasmodium chabaudi adami. | to explore cell-mediated immune mechanisms in host defense against malaria, we utilized a murine model system in which antibody-independent mechanisms of immunity are known to play a major role. splenic t lymphocytes obtained from plasmodium chabaudi adami-immune mice were maintained in vitro by using il 2-containing medium and frequent antigenic stimulation. these il 2-propagated t lymphocytes were characterized for their antigen reactivity, surface phenotype, and ability to confer protection t ... | 1986 | 2423609 |
| cloning of genomic fragment from plasmodium chabaudi expressing a 105 kilodalton antigen epitope. | the 105 kda antigen of plasmodium chabaudi has many characteristics of the p. falciparum pf 155 (resa) molecule. a clone (ppc105e) from a p. chabaudi genomic library was isolated using immune screening with a 105 kda antigen specific monoclonal antibody (b7e10). southern, northern and western blotting analyses provide evidence for a lack of variability at the protein and dna levels. a subclone of the insert in the expression vector pex2, synthesises a fusion peptide which contains the epitope re ... | 1988 | 2452981 |
| plasmodium chabaudi antigen pch105, plasmodium falciparum antigen pf155, and erythrocyte band 3 share cross-reactive epitopes. | by immunoblotting with a number of monoclonal antibodies raised in human and murine malaria systems, we have been able to establish the presence of cross-reactive epitopes on the plasmodium falciparum vaccine candidate antigen pf155/resa and its proposed plasmodium chabaudi analog pch105. these findings were confirmed when the same antibodies were tested in an immunofluorescence assay. by using short synthetic peptides corresponding to repeated sequences in the c terminus of the pf155 and enzyme ... | 1988 | 2453468 |
| cloned t cells provide help for malaria-specific polyclonal antibody responses. | athymic mice grafted with antigen-reactive cloned t cells and challenged with plasmodium chabaudi adami produced antibodies against multiple parasite antigens. antibody reactivities were similar to those seen in infected euthymic mice and contrasted with their absence in infected athymic mice. these results suggest that it will not be possible to determine the antigenic specificity of clonal t cell populations in malarial infections by their capacity to provide help to restricted populations of ... | 1989 | 2468507 |
| a protective monoclonal antibody recognizes a linear epitope in the precursor to the major merozoite antigens of plasmodium chabaudi adami. | the monoclonal antibody 5c10/66 was shown to afford strong protection in mice against fulminating plasmodium chabaudi adami infection. this was remarkable, as immunity to this organism is regarded to be mainly t-cell mediated. this antibody identified a 250-kda molecule in schizonts and an 83-kda fragment in merozoites. a cdna clone selected by 5c10/66 was the homologue of the plasmodium falciparum precursor to the major merozoite surface antigen (pmmsa). comparison with the p. falciparum sequen ... | 1989 | 2471191 |
| cross-reacting antigens to pc96, a protective antigen of plasmodium chabaudi, in p. falciparum, p. vivax, and p. cynomolgi. | mice can be partially protected against plasmodium chabaudi by immunization with the antigen pc96, isolated from the erythrocyte membranes of infected mice. we used a pc96 specific monoclonal antibody to identify antigens which cross-react with pc96 in p. falciparum, p. vivax, and p. cynomologi. the cross-reactive molecules are antigens of mr 155,000 in p. falciparum, mr 220,000 in p. cynomologi. they are located in the surface membranes of infected erythrocytes. pc96 is characterized by immunoe ... | 1989 | 2472747 |
| serine hydroxymethyltransferase from pyrimethamine-sensitive and -resistant strains of plasmodium chabaudi. | serine hydroxymethyltransferase (ec 2.1.2.1) was partially purified from a pyrimethamine sensitive strain of plasmodium chabaudi. km values of 2.91 and 1.08 mm were determined for tetrahydrofolate and serine, respectively. the effects of ph, of temperature and of some potential inhibitors were determined. the enzyme was also partially purified from a pyrimethamine-resistant strain of p. chabaudi and subjected to the same regime. no differences between the enzymes from the two sources could be de ... | 1989 | 2495446 |
| production of interferon-gamma during infection of mice with plasmodium chabaudi chabaudi. | an elisa assay, designed to detect interferon-gamma (ifn-gamma) in the picogram range, was used to study the presence of ifn-gamma in serum and its production by t cells taken from c57bl/6 mice infected with plasmodium chabaudi chabaudi. ifn-gamma was detectable in mouse plasma for two to three days before the peak of parasitaemia. similarly, ifn-gamma production by t cells could be detected in vitro. in limiting dilution cultures, the production of ifn-gamma by as few as 1,000 t cells was detec ... | 1989 | 2515153 |
| frequencies of cd4+ t cells reactive with plasmodium chabaudi chabaudi: distinct response kinetics for cells with th1 and th2 characteristics during infection. | the functional heterogeneity of the cd4+ t cell response to plasmodium chabaudi has been evaluated. using a limiting dilution assay system and a variety of assays to detect gamma-interferon (ifn-gamma), interleukin-2 (il-2), il-3, and t helper (th) cells for malaria-specific antibody production, the precursor frequencies of p. chabaudi-reactive t cells have been calculated. the patterns of lymphokines produced by individual microcultures of the limiting dilution assay generally supported the ide ... | 1989 | 2535135 |
| requirement for lipopolysaccharide for enhanced in vitro superoxide producing competence in macrophages from normal and malaria (plasmodium chabaudi) infected mouse spleen. | nucleated cells from mouse spleens were suspended in rpmi-1640 medium and plated in polystyrene tissue culture dishes with or without lipoplysaccharide (lps, endotoxin) and incubated at 37 degrees c for 3 h in a humid incubator under 5% co2. adherent spleen cells obtained from uninfected control or plasmodium chabaudi-infected mice showed negligible superoxide (o2) production in vitro, in response to triggering with phorbol myristate acetate (pma). however, o2 release increased in a concentratio ... | 1989 | 2553546 |
| reassessment of the role of splenic leukocyte oxidative activity and macrophage activation in expression of immunity to malaria. | the role of splenic leukocyte oxidative activity and macrophage activation in the development of protective immunity was examined during acute plasmodium chabaudi adami malaria. splenic leukocyte oxidative activity was compared in infected balb/c and p/j mice; the latter are known to suffer from defects in macrophage function. phorbol myristate acetate-stimulated chemiluminescence and superoxide anion production by splenic leukocytes from infected balb/c mice were found to be increased dramatica ... | 1989 | 2553611 |
| role of mononuclear phagocytes in elimination of plasmodium chabaudi as infection. | the role of mononuclear phagocytes in acquired immunity resulting in the intraerythrocytic destruction and elimination of malarial parasites was investigated in the murine model of infection with plasmodium chabaudi as. mice were treated 1 day before or 6 days after infection with agents which either result in augmentation or activation of the non-specific, microbicidal effector function of mononuclear phagocytes or in depletion of cells of this lineage. to examine the effect of agents which act ... | 1989 | 2555763 |
| the use of a dna probe for the differentiation of rodent malaria strains and species. | a clone, pcsv4, derived from a partial genomic library of the rodent malaria plasmodium chabaudi chabaudi as strain, contains an insert which when used as a probe at low stringency in southern blotting of genomic dna from a variety of strains, subspecies and species of rodent malaria parasites, results in a pattern of hybridisation which is specific to each of the dna samples used, thus providing an accurate method to define a rodent malaria line. the insert only hybridises to dna derived from m ... | 1989 | 2563146 |
| limiting dilution analysis of the t cell response to plasmodium chabaudi chabaudi in mice. | a limiting dilution assay system was developed in order to measure the in-vitro t cell response to antigens of the erythrocytic stages of plasmodium chabaudi. the conditions of the assay are such that only cd4+ t cells are able to respond. the assay allows the determination of the frequencies of t cells which proliferate and/or which develop into helper cells for antibody production during a primary infection. a specific response from splenic t cells can be measured as early as 7 days after infe ... | 1989 | 2573876 |
| the response of cd4+ t cells to plasmodium chabaudi chabaudi. | we have studied the role of cd4+ t cells in the immune response to plasmodium chabaudi chabaudi. from in vivo experiments in which the different subsets of t cells were depleted, it is clear that cd4+ t cells are essential for the generation of protective immunity. our limiting dilution analysis show that the cd4 t-cell response to p. chabaudi antigens is heterogeneous, in that distinct functions can be performed by different responding t cells, and these responses change during infection. durin ... | 1989 | 2575075 |
| use of a dna probe to analyse the dynamics of infection with rodent malaria parasites confirms that parasite clearance during crisis is predominantly strain- and species-specific. | a dna probe, pcsv4.1, isolated from plasmodium chabaudi chabaudi as, generates in southern blotting experiments restriction fragment length polymorphisms specific to a particular rodent malaria parasite line. it was used to develop an assay which allows identification and semi-quantitative compositional analysis of sample parasite populations in which one or more strains, subspecies or species were present. in experiments where mechanisms effecting parasite clearance during crisis were studied, ... | 1989 | 2575707 |
| invasion of mature and immature erythrocytes of cba/ca mice by a cloned line of plasmodium chabaudi chabaudi. | during the early stages of the primary plasmodium chabaudi chabaudi as parasitaemia in cba/ca mice this parasite invaded normocytes, but as the parasitaemia developed increasing numbers of parasites were seen within reticulocytes. during and just after peak parasitaemia, as further parasite replication was controlled, the 'crisis' phase ensued, mice became increasingly anaemic and reticulocyte numbers were markedly increased. as the parasitaemia was resolved during crisis in excess of 25% of par ... | 1989 | 2594410 |
| antifolate drug selection results in duplication and rearrangement of chromosome 7 in plasmodium chabaudi. | we selected lines of plasmodium chabaudi that are resistant to high levels of the antifolate drug pyrimethamine and have shown that rearrangement and duplication of a portion of chromosome 7 has occurred in the resistant lines. this chromosomal duplication results in an increase in the chromosome number from 14 to 15: two derived chromosomes (450 kilobases and 1.1 megabases) were smaller than the original chromosome 7 (1.3 megabases), so that essentially only a 200-kilobase region was duplicated ... | 1989 | 2601715 |
| structure of the apical membrane antigen i (ama-1) of plasmodium chabaudi. | | 1989 | 2608101 |
| acute virulent infection with plasmodium chabaudi does not impair the generation of a protective immune response. | we have investigated whether a protective immune response occurred in mice infected with a virulent cloned strain of plasmodium chabaudi. animals inoculated intravenously with 10(7) parasitized erythrocytes (pe) showed an exponentially increasing parasitaemia and died by day 6 of the infection, presenting a pronounced anaemia. smaller inocula produced a longer pre-patent period but did not change the lethal course of infection, since mice injected with 100 parasites died on day 12. when anaemia ... | 1989 | 2616190 |
| protective effect of severe magnesium deficiency on plasmodium chabaudi infection. | mice were fed for 30 days on purified diets containing 50 (severely mg deficient diet), 100 (moderately mg deficient diet) and 1300 mg/kg (control diet). an additional group raised on stock uar diet was also used for the experiment. the mice were maintained on the experimental diets for 12 days before being inoculated with p. chabaudi. infection evolved similarly in mice fed the control purified diet, moderately mg deficient diet and the stock diet whereas the severely mg deficient diet induced ... | 1989 | 2640902 |