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antigen-specific and concanavalin a-induced lymphocyte blastogenesis responses during the course of plasmodium berghei infection in rats.antigen specific and concanavalin a (con a)-induced lymphocyte blastogenesis responses were monitored in the spleens of rats infected with plasmodium berghei. con a responses were depressed only at the time of peak parasitaemia. the antigen specific blastogenesis response was either not in evidence, or at a low level during the periods of patent or subpatent infection (up to 8 weeks after infection). higher levels of blastogenesis were seen from 8 to 12 weeks after infection, which correlates wi ...19846390300
characterization of macrophage dysfunction in rodent malaria.immunosuppression in malaria has been attributed, in part, to alterations in macrophage function. the present study was undertaken in an attempt to characterize the dysfunction and to determine if it is regional or if it occurs in different populations of macrophages. the resting o2 consumption of either hepatic, splenic, or peritoneal macrophages or polymorphonuclear neutrophils (pmns) was unaltered by the malaria infection. however, the respiratory burst was significantly enhanced in the three ...19846389742
fine structure of plasmodium berghei exoerythrocytic forms in cultured primary rat hepatocytes.sporozoites of the rodent malaria parasite plasmodium berghei have been grown in primary cultures of hepatocytes from brown norway rats. the ultrastructure of in vitro grown exoerythrocytic forms was compared with that of parasites in vivo. peculiar vesicles, previously not described in vivo, were identified and their possible origin is discussed. otherwise, the fine structure of the hepatocytic stages grown in vitro was shown to be grossly similar to those in vivo. therefore, electron microscop ...19846388852
blood changes and enhanced thromboxane and 6-keto prostaglandin f1 alpha production in experimental acute plasmodium bergei infection in hamsters.golden hamsters inoculated intraperitoneally with plasmodium bergei infected mouse blood regularly developed p. bergei parasitaemia. this was associated with progressive thrombocytopenia and leucocytosis as the degree of parasitaemia increased with time. when infected whole blood was stimulated with collagen, significantly enhanced thromboxane b2 (txb2) production per platelet was seen. 6-keto prostaglandin (pg) f1 alpha formation in the same system increased from the sixth infection day onwards ...19846388013
early lymphocyte trapping in malaria infections: a particulate antigen mediated phenomenon.during the course of rodent malaria a marked decrease in the numbers of circulating lymphocytes within the peripheral blood occurred 2-4 days post-infection. monocytes and polymorphs did not show the same degree of decline. for both avirulent plasmodium yoelii and lethal plasmodium berghei infections lymphocyte numbers returned to control levels by day 6-8 post-infection. while these levels were maintained until clearance of p. yoelii infection, a sustained and abnormal increase occurred during ...19846387079
increased phagocytosis of non-parasitized red cells in plasmodium berghei malaria. 19846385888
evidence for major differences in ribosomal subunit proteins from plasmodium berghei and rat liver.purified polysomes were isolated in high yield from the erythrocytic stages of the rodent malaria parasite, plasmodium berghei, and from rat liver. proteins extracted from the ribosomal subunits derived from these polysomes were fractionated and their number and molecular weights were estimated by two-dimensional polyacrylamide gel electrophoresis. plasmodial small ribosomal subunits contained 30 proteins ranging in apparent molecular size from 11.7 to 40.7 kda, while large subunits contained 35 ...19846384776
[mathematical model of the dynamics of parasitemia in mice infected with p. berghei]. 19846384757
h-2 dependent differential course of experimental plasmodium berghei infections. 19836382900
evolutionary relatedness of plasmodium species as determined by the structure of dna.malaria parasites can be grouped evolutionarily by analysis of dna composition and genome arrangement. those that vary widely with regard to host range, morphology, and biological characteristics fit into only a small number of distinctive groups. the dna of the human parasite plasmodium falciparum fits into a group that includes rodent and avian malarias and is unlike the dna of other primate malaria parasites. the dna of plasmodium vivax, which is also a human parasite, fits into a distinctly ...19846382604
chloroquine resistance and host cell hemoglobin catabolism in plasmodium berghei. 19846382314
host superoxide dismutase incorporation by intraerythrocytic plasmodia. 19846382311
ferriprotoporphyrin ix: a mediator of the antimalarial action of oxidants and 4-aminoquinoline drugs.ferriprotoporphyrin ix (fp) is released from hemoglobin by oxidative denaturation or by proteolytic degradation. fp added exogenously to cells or released intracellularly is a lytic toxin. chloroquine enhances the accumulation of exogenous fp in cellular membranes and potentiates its lytic effect. menadione is an example of an oxidant drug that denatures hemoglobin, releases fp intracellularly, and thereby lyses cells. chloroquine increases the accumulation of fp in the membranes of menadione-tr ...19846382310
glutathione metabolism in malaria infected erythrocytes. 19846382309
long-term in vitro cultures of plasmodium berghei and preliminary observations on gametocytogenesis. 19846381348
plasmodium berghei: the effects of suppressor factor on vaccination. 19846381347
relation between haemoglobin degradation and maturity of the red blood cell infected by p. berghei.the action on haemoglobin of p. berghei growing in mature red cells, p. berghei growing in reticulocytes and p. berghei r.c. (which grows almost exclusively in reticulocytes) was compared. p. berghei growing in reticulocytes had a much higher level of proteolytic activity on haemoglobin than that of p. berghei growing in mature red cells. the amount of residual hematin was considerably reduced. in p. berghei r.c. and p. berghei growing in reticulocytes, the pigment seems to be exocyted as it is ...19846380913
[growth and decline of parasitemia in trophozoite-induced plasmodium berghei and plasmodium yoelii infection in mice]. 19836380802
plasmodium berghei infection in mice: effect of low-level ozone exposure. 19846380627
[action of chloroquine on glutathione metabolism in erythrocytes parasitized by plasmodium berghei].chloroquine acts on erythrocytes parasitized by a p. berghei sensitive strain, inducing a dramatic decrease of the intra erythrocytic reduced glutathione. this reduction follows a decrease of the glutathione reductase activity. contrarily when erythrocytes are parasitized by a p. berghei resistant strain neither the intra erythrocytic reduced glutathione nor the glutathione reductase activity are modified by the action of chloroquine. glutathione metabolism could be the main target of action of ...19846380377
a simple method for isolating plasmodium berghei-infected erythrocytes from experimentally infected animals. 19846380033
establishment of ancylostoma ceylanicum adult infection in plasmodium berghei-infected albino mice(mus musculus) 19846380028
[study of anemia and thrombopenia in plasmodium berghei malaria]. 19846379829
two major sequence classes of ribosomal rna genes in plasmodium berghei.primary sequence differences have been found between two different ribosomal dna (rdna) units of the rodent malaria parasite, plasmodium berghei, within the coding areas of both the small and large ribosomal rnas (rrna). the coding regions of rdna unit a are protected from nuclease s1 digestion by rrna isolated from asexual blood stage parasites. under the same conditions of analysis, the comparable coding regions from unit c are cut into small pieces by nuclease s1, the largest being 1.1 kb. an ...19846379606
identification of 5 s and 5.8 s ribosomal rna molecules and their genes in plasmodium berghei.the ribosomes of plasmodium berghei contain two small rna molecules approximately 150 and 120 bases long. these correspond in size to 5.8 and 5 s rna molecules found in the cytoplasmic ribosomes of eukaryotic cells. segments homologous to the 5.8 s rna are present in each of the four ribosomal rna gene units. restriction fragments which span the region between the coding areas of the two major ribosomal rna molecules hybridize to 5.8 s rna, indicating that the gene is located between the small a ...19846379449
antigenic analysis of soluble extract of plasmodium berghei using sodium dodecyl sulphate polyacrylamide gel electrophoresis. 19846378779
interrelationship of age of host, immunity & plasmodium berghei infection. 19846378778
lipid antigens derived from erythrocytes infected with plasmodium berghei.lipids were extracted from red blood cells infected with plasmodium berghei, from the membranes of infected red cells and from free parasites. a radioimmunoassay was used to detect antibodies to these lipids in sera from convalescent and immune rats. most of the antigenic activity could be attributed to the parasite although some activity was found in lipids isolated from the membranes of infected red blood cells. absorption studies showed that the binding was specific for malarial lipid antigen ...19846377726
lipoprotein lipase suppression in 3t3-l1 cells by a haematoprotozoan-induced mediator from peritoneal exudate cells.lysates of the haematoprotozoa trypanosoma brucei or plasmodium berghei stimulated murine peritoneal exudate cells to release a mediator, which suppressed lipoprotein lipase activity in differentiating 3t3-l1 preadipocytes. the parasite-induced mediator suppressed the activity of cell surface lipoprotein lipase up to 39% in a dose dependent manner. by impairing the activity of cell surface lipoprotein lipase, this mediator acts to inhibit the uptake of fatty acid, and ultimately the accumulation ...19846377200
riboflavin deficiency inhibits multiplication of malarial parasites. 19846377134
susceptibility of anopheles punctipennis and other florida mosquitoes to plasmodium berghei. 19846376750
the malarial pigment in rat infected erythrocytes and its interaction with chloroquine. a mössbauer effect study.mössbauer studies of rat erythrocytes infected by plasmodium berghei malaria parasites, using 57fe-enriched rat red blood cells, were carried out in order to determine the physical parameters which characterize the malarial pigment iron and to test the effect of the widely used antimalaria drug, chloroquine, on these parameters. the iron in the malarial pigment which is derived from hemoglobin digestion by the intracellular parasite was found to be trivalent, high spin, with mössbauer parameters ...19846376502
host defenses in murine malaria: humoral immunity to plasmodium berghei in mice.humoral immunity to plasmodium berghei infection of f1 hybrid b6d2 (c57b1/6 x dba/2) mice was investigated using an immune serum prepared from mice which survived a lethal challenge of erythrocytic stage p. berghei because of previous vaccination with formalin-killed p. berghei. immune serum, but not normal serum, if injected intraperitoneally or intravenously soon after infection, during rapidly increasing parasitemia, transiently inhibited the progress of infection in a pattern which was direc ...19846375406
action of a new floxacrine derivative (s 82 5455) on asexual stages of plasmodium berghei: a light and electron microscopical study.the floxacrine derivative s 82 5455, 7-chloro-1-( 4n - methylpiperazino -1n-imino)-10-hydroxy-1, 2, 3, 4-tetrahydro-3-(4-trifluoromethylphenyl)-9(10 h)- acridone , shows a high activity against blood induced infection of a drug-sensitive line of plasmodium berghei in mice and rats. the dosis curativa minima/ dosis tolerata maxima values against the drug-sensitive p. berghei strain ascertained in the '28-day test' in mice, were 1.56 (x 5)/400 (x 1) mg/kg after the oral route 3.12(x 5)/400(x 1) mg ...19846375212
effect of salinomycin-na on malaria parasites (plasmodium falciparum and p. berghei).in vitro exposure of plasmodium falciparum and p. berghei to salinomycin-na showed that 10 min incubation in rpmi 1640 medium containing 100 micrograms/ml of the polyether antibiotic led to complete destruction of most parasites; in media containing 10 or 1 microgram/ml salinomycin-na some young developmental stages seemed to survive, apparently due to the protection of the mostly intact host cell. in vitro treatment of rats infected with p. berghei revealed that a single subcutaneous (oral) dos ...19846375210
role of macrophages in malaria: o2 metabolite production and phagocytosis by splenic macrophages during lethal plasmodium berghei and self-limiting plasmodium yoelii infection in mice.the role of splenic macrophages in resistance to lethal plasmodium berghei or self-limiting plasmodium yoelii was studied by testing their rate of phagocytosis and their production of o2 metabolites (h2o2 and o2-) upon nonspecific stimulation with zymosan. it was found that, compared with p. berghei, infection of mice with p. yoelii resulted in an earlier appearance and in higher numbers of adherent cells in the spleen. furthermore, the capacity of macrophages to generate o2 metabolites was sign ...19846373617
isolation of a single messenger rna and of the corresponding gene in plasmodium berghei.a genomic library of plasmodium berghei dna was constructed using lambda 47.i as a vector. it represents 90% of plasmodium genome. genes expressed during the intraerythrocytic stage of p. berghei were isolated among the recombinant clones of the library using labelled cdna complementary to the polya + plasmodium mrna extracted during this stage. the purified coding strand of an expressed clone was utilized to catch the corresponding mrna(s). the hybridized mrna fraction was eluted and in vitro t ...19846373026
metabolism of erythrocyte infected with malaria parasite and the action of antimalarial drugs. 19836372794
lysosomal enzymes in the spleen of albino rats, mice and mastomys natalensis during plasmodium berghei infection.activities of certain acid hydrolases of the spleen were followed in three different rodents during the course of plasmodium berghei infection. in albino rats where sterile immunity against the infection develops, the specific activities of a few acid hydrolases first declined then increased from day 7 and showed a several-fold increase over control values when there were no detectable parasites in peripheral circulation. in contrast, in mastomys natalensis and albino mice which succumb to infec ...19836372771
comparison of in vitro and in vivo antimalarial activities of 9-phenanthrenecarbinols.analysis of the antimalarial activity of a selected series of 17 9-phenanthrenecarbinols against cultured strains of plasmodium falciparum and against p. berghei in mice following oral administration indicated that the rankings of activities within the series were influenced by substituents on the 9-carbinol and the route of administration. compounds with alkylamino-alkyl groups were ranked as most active by an in vitro screening system which assayed activity against chloroquine-sensitive and ch ...19846372713
[sensitivity of the erythrocytes of mice infected with plasmodium berghei to saponin and a hypotonic solution]. 19846371469
anti-intermediate filament antibody in mice infected with plasmodium berghei.fifteen mice (cba) were infected with lethal plasmodium berghei and the development of anti-intermediate filament antibody (anti-if) studied. sera from all the infected animals reacted with the cytoplasmic network of intermediate filaments (if) in the human epidermal laryngeal carcinoma (hep2) cell line, as demonstrated by indirect immunofluorescence. sera from 5 control animals injected with 10(4) unparasitized red cells showed no anti-if reactivity. anti-if of igm class was first detectable at ...19846371238
enhancement of phagocytosis of parasitized and nonparasitized red cells in acute plasmodium berghei malaria.the phagocytosis by mouse peritoneal macrophages of parasitized red cells (prcs) and nonparasitized red cells (nonprcs) separated from plasmodium berghei infected blood was studied in vitro. peritoneal macrophages from acutely infected mice and normal mice were cultured on coverslips. prcs and nonprcs were fractionated by ficoll density gradient centrifugation from plasmodium berghei infected blood. prcs were fed in triplicate cultures to normal macrophages in normal serum, normal macrophages in ...19846371136
malaria parasites do not contain or synthesize sialic acids.the capacity of plasmodia to synthesize sialic acids was investigated by adding radioactive acetate to short-term in vitro cultures of the intraerythrocytic asexual forms of three malaria parasites (the human malaria plasmodium falciparum in aotus trivirgatus erythrocytes; the simian malaria p. knowlesi in rhesus monkey erythrocytes; the rodent malaria p. berghei in mouse erythrocytes) and to cultures of extracellular zygotes of the avian malaria p. gallinaceum. radioactive acetate was added to ...19846370820
hepatic superoxide dismutase activity in the mouse infected with plasmodium berghei.the effects of malarial infection, induced by infecting the mouse with plasmodium berghei (30-40% parasitemia), on hepatic superoxide dismutase (sods) were studied. total sod and cu-zn sod activities were found to be significantly reduced. mn sod activity, however, was not found to be altered.19846370802
[effects of anti-infectious immunomodulators in leprosy and malaria in the mouse].immunomodulators, whether natural (polysaccharides) or industrial (non-hemolytic detergents) proved active by themselves, in preventive or curative schemes of experimental leprosy and malaria. however, their activity was most often increased, through joint administration with chemotherapeutic agents.19836370479
differential susceptibility of rodent malaria parasites to nonspecific immunity.nonspecific immunity to rodent malaria parasites can be produced by immunising mice with heterologous parasites or pretreating them with bcg, corynebacterium parvum or brucella abortus. nonspecific immunity is easily produced against plasmodium vinckei but not p. berghei. this is due to the difference between the cells occupied by the parasites, young red blood cells in the case of p. berghei and mature red blood cells in the case of p. vinckei.19836370475
malarial immunity in pregnant mice, in relation to total and unbound plasma corticosterone.a pregnancy dependent loss of malarial immunity is accompanied by an (excessive) increase of total as well as free plasma corticosterone. this loss of immunity was largely prevented by adrenalectomy. moreover, malarial immunity was more sensitive to dexamethasone immunosuppression during pregnancy. primary infections are more virulent during pregnancy and like in recrudescent mice, cause excessive total and free plasma corticosterone levels. corticosterone may be considered an immuno-regulatory ...19836370474
identification of malaria-infected mosquitoes by a two-site enzyme-linked immunosorbent assay.a micro enzyme-linked immunosorbent assay (elisa) for identifying malaria sporozoites in mosquitoes is described. using an extract of dried infected mosquitoes as antigen, a two-site elisa was sensitive enough to detect one infected mosquito in a pool of 20. the species specificity, sensitivity and ease of performance of this assay, as well as the stability of the reagent, should make it a useful epidemiological tool.19846370003
effect of 60co-irradiation on the development and immunogenicity of plasmodium berghei sporozoites in anopheles stephensi mosquitoes.protection conferred to mice by plasmodium berghei sporozoites increased significantly when the time interval between 60co-irradiation of the infected mosquitoes and harvest of sporozoites increased. one thousand sporozoites conferred no protection against challenge if harvested on the day of irradiation, but protected 60% of recipient mice when harvested 28 days postirradiation. when the time between feeding of mosquitoes and irradiation was varied, sporozoites from mosquitoes irradiated 3 days ...19836368786
differences in plasmodium berghei development in nude and normal mice. 19846368438
murine malaria: immune complexes inhibit fc receptor-mediated phagocytosis.immune complexes have been partially purified from the serum of plasmodium berghei-infected mice by ultracentrifugation on 10 to 40% linear sucrose gradients, by precipitation with polyethylene glycol, and by gel filtration through sephacryl s-300. the complexes contain gamma 1, gamma 2a, gamma 2b, and gamma 3 subclasses of mouse immunoglobulin g in differing amounts, as well as malarial antigen. complexes isolated by all three methods inhibit fc receptor-mediated phagocytosis by normal mouse pe ...19846368390
pulmonary edema in mice infected with plasmodium berghei. involvement of catecholamines.mice inoculated with plasmodium berghei developed a drastic and significant pulmonary edema. treatment of animals with phenoxybenzamine rendered mice hyporeactive to this physiopathological alteration.19846365585
cell-mediated immunity in rats injected with an antimalaria t-cell line.the aim was to develop a pure t-cell line which would enable the study of some aspects of the cellular immunity of malaria-injected rodents. for this purpose a long-term proliferative antimalaria t-cell line (amtl) was established. the line was developed from splenocytes of rats recovered from a plasmodium berghei infection. after adoptive transfer of the amtl, some protection was demonstrated either by a lower mortality rate after challenge with the parasite or by decreased parasitemia in the t ...19846365332
interaction of antimalarial drugs with hemin.hemin (ferriprotoporphyrin ix) is shown to form complexes with the chloroquine class of antimalarial drugs. the soret band of hemin becomes optically active upon the addition of chiral drugs. results on the hemin-induced quenching of the fluorescence of chloroquine are consistent with the formation of a 2:1 hemin:drug complex with a formation constant of 1.4 x 10(7) at 298 k. also a direct comparison of the drug-treated and drug-free parasites themselves, by the noninvasive photoacoustic spectro ...19836365196
topographical distribution of the cerebral lesions in mice infected with plasmodium berghei.in the mouse p. berghei malaria model systematic studies were carried out on the relationship between the type and the topographical distribution of the brain lesion in cerebral malaria. as previously stated for pernicious p. falciparum malaria in man, petechial haemorrhage was not the sole morphologic lesion. in addition to severe brain oedema, microthrombosis, sludging of mononuclear cells, arteriolar spasms, scattered disturbances of the microcirculation, and the occasional proliferation of g ...19836364514
circadian temperature rhythm and circadian-circaseptan (about 7-day) aspects of murine death from malaria.about-7-day (circaseptan) and circadian rhythms were sought and found in host-parasite relations of mice infected with plasmodium berghei. five inbred male dba mice, about 18 weeks of age, were implanted with transsensors for temperature telemetry. core temperature, monitored every 10 min for 3 days before the intravenous or intraperitoneal inoculation of 10(5) infected erythrocytes and thereafter until death, was analyzed by cosinor. a statistically highly significant circadian rhythm exhibited ...19846364151
synthesis and antimicrobial activity of clindamycin analogues: pirlimycin, 1,2 a potent antibacterial agent.the preparation of a series of analogues of clindamycin is described in which the naturally occurring five-membered cyclic amino acid amide portion of the molecule is replaced by a four-, six-, or seven-membered cyclic amino acid amide. the most interesting compound is pirlimycin (7e, u-57,930e), in which the (2s-trans)-4-n-propylhygramide portion of clindamycin is replaced by (2s-cis)-4-ethylpipecolamide. this structural modification results in significantly favorable changes in toxicity, metab ...19846363698
plasmodium berghei: eosinophilic depression of infection in mice.the effects of eosinophilia on the course of plasmodium berghei infection in mice were studied. eosinophilia was induced by intravenous injection of ascaris suum body fluid into the mice. results indicated that eosinophils may play a role in the suppression of murine malaria. a significant reduction in parasitemias and increased survival time in eosinophilic mice occurred compared to mice not treated with a. suum body fluid. reduction of parasitemia was effectively achieved when the mice were ch ...19846363116
alkali-extraction of membranes from mouse erythrocytes infected with plasmodium berghei.alkali-extracted membrane material from hypotonically lysed plasmodium berghei-infected mouse erythrocytes has been analyzed by dodecyl sulphate polyacrylamide gel electrophoresis and fractionated by discontinuous sucrose gradient centrifugation. components characteristic for the protein pattern associated with p. berghei infection have been recovered in the alkali-extracted material. parasite components, free of host cell membrane contamination, have been obtained as a high-density fraction fro ...19836362976
anti-lymphocyte autoantibodies in lethal mouse malaria and their absence in an irradiation-induced non-lethal variant. 19846362936
plasmodium berghei: physiopathological changes during infections in mice.using infections of plasmodium berghei in laboratory mice, the following physiopathological changes were observed during the seven days of the infection: reduction in haematocrit, increases in parasitized erythrocytes, pulmonary oedema, hypothermia, formation of prostaglandin-like substances in the central nervous system, increases and decreases in plasma bradykininogen levels and leucocytosis, as evidenced by neutrophilia, lymphocytosis and monocytosis. we found no changes in total plasma prote ...19836362586
[plasmodium berghei-strongyloides ratti interaction: experimental modification and mechanism]. 19836362579
the influence of riboflavin deficiency on plasmodium berghei infection in rats.two experiments were done in which rats in various stages of riboflavin deficiency were infected with plasmodium berghei. various control groups were included to compare the influence of food restriction on the p. berghei infection with that of riboflavin deficiency, namely, pair-fed (pf), weight-matched (wm) and ad libitum-fed (c-al) control groups. riboflavin deficiency depressed maximum parasite counts by comparison with all control groups and the degree of depression was inversely related to ...19836362121
2-acetylpyridine thiosemicarbazones. 9. derivatives of 2-acetylpyridine 1-oxide as potential antimalarial agents.in view of the antimalarial activity in mice of 2-acetylpyridine thiosemicarbazones, a series of analogous 1-oxides was prepared for evaluation. their synthesis was achieved by the reaction of 2-acetylpyridine 1-oxide with methyl hydrazinecarbodithioate to give methyl 3-[1-(2-pyridinyl 1-oxide)ethylidene]hydrazinecarbodithioate (ii). reaction of the latter intermediate with secondary amines afforded the desired 2-acetylpyridine 1-oxide thiosemicarbazones (iii). reduction of the azomethine linkag ...19846361258
2-acetylpyridine thiosemicarbazones. 8. derivatives of 1-acetylisoquinoline as potential antimalarial agents.a series of 1-acetylisoquinoline thiosemicarbazones was prepared in order to evaluate their antimalarial properties. this was achieved by the reaction of 1-acetylisoquinoline with methyl hydrazinecarbodithioate to give methyl 3-[1-(1-isoquinolinyl)ethylidene]hydrazinecarbodithioate (ii). displacement of the s-methyl group from this intermediate by various primary and secondary amines afforded the desired 1-acetylisoquinoline thiosemicarbazones (iii). thiosemicarbazides in which the azomethine mo ...19846361257
malaria vaccine antigen(s): detergent solubilization, partial isolation, and recovery of immunoprotective activity.plasmodium berghei-infected erythrocytes were solubilized with the nonionic detergent n-octyl glucoside and membrane-containing p. berghei fragments with either n-octyl glucoside or the ionic detergent sodium deoxycholate. unsolubilized material was separated by centrifugation, and the detergent was removed from the respective supernatants by gel filtration. reaggregated components in the respective void volume eluates acted as a specific vaccine in recipient mice, resulting in a dose-related ac ...19846360908
synthesis and biological activity of some di(nitrothienyl)- and di(acetylaminothienyl)sulfones.some new di(nitrothienyl)- and di(acetylaminothienyl)sulfones were synthesized. compounds (i)-(vi) were active against several gram-positive bacteria, in vitro. di(5-acetylamino-2-thienyl)sulfone (vii) showed a mild antimalarial activity against a drug-sensitive strain of p. berghei in mice.19836360709
[effect of a milk diet on parasitemia suppression and on the development of humoral immunity during the course of malarial infection in mice]. 19836358774
malaria-induced lymphokines: stimulation of macrophages for enhanced phagocytosis.culture supernatants from antigen-pulsed spleen cells of mice infected previously with either bcg or plasmodium chabaudi were used to study macrophage activation as judged by phagocytosis of immunoglobulin g-sensitized erythrocytes and plasmodium berghei- and p. chabaudi-infected erythrocytes. resident peritoneal macrophages were incubated in vitro with spleen cell factor and then assayed for ingestion of immunoglobulin g-sensitized or parasitized erythrocytes. macrophages activated with bcg-ind ...19836358030
failure to induce splenomegaly in balb/c mice using rodent malaria culture supernatants.uninfected male and female balb/c mice were given a twice weekly intraperitoneal injection, of supernatants obtained from 24-h cultures of plasmodium berghei-infected and control mouse red blood cells, for 5 weeks. the mice were then weighed along with uninjected controls. all the animals were sacrificed by chloroform anaesthesia and their spleen weights measured. mice receiving malaria culture supernatants had statistically similar spleen weights to those receiving control culture supernatants. ...19836358008
heterologous immunity in rodent malaria: comparison of the degree of cross-immunity generated by vaccination with that produced by exposure to live infection.the degree of heterologous immunity occurring between the different rodent malarias was examined. mice immunized with a killed vaccine consisting of formalin-fixed blood-stage parasites mixed with saponin, were challenged with homologous or heterologous parasites and the degree of protection assessed by monitoring the number of survivors and the duration and severity of parasitaemia. the results indicated that vaccination conferred strong cross-protection between two different plasmodium yoelii ...19836357121
ultrastructural observations on the infection of rat liver by plasmodium berghei sporozoites in vivo.the invasion of liver parenchymal cells by sporozoites of plasmodium berghei vincke & lips, 1948, was studied in vivo using transmission electron microscopy. livers of brown norway rats were examined 30 and 60 min after intraportal injection of 15 million sporozoites each. sporozoites found after incorporation into vacuoles in hepatocytes were often located near a bile canaliculus at the lateral cell surface, surrounded by hepatocyte lysosomal structures; however, degradation of sporozoites caus ...19836355454
an in vitro assay system for the identification of potential antimalarial drugs.current models for antimalarial drug screening generally measure the survival of drug-treated rodents infected with plasmodium berghei. modifications of existing continuous culture methods for p. falciparum allow the rapid, accurate and economical determination of drug effects directly against the human pathogen. parasite cultures can be maintained in rpmi 1640 medium supplemented with human or rabbit serum or with hypoxanthine-supplemented bovine serum. the antiparasite effects of four drugs, c ...19836355423
effect of trauma on malaria infection. 19836353779
cloning and characterization of a ribosomal rna gene from plasmodium berghei.the ribosomal rna (rrna) of plasmodium berghei strain nyu2 was characterized with respect to size and used to identify molecular clones of ribosomal rna genes (rdna) from this organism. the intact large rrna species (mr 1.40 x 10(6] is intermediate in size between prokaryotic and eukaryotic large rrnas. it is specifically cleaved in vivo near the 5'-end yielding one large component (mr 1.10 x 10(6] and one small component (mr 0.30 x 10(6]. the small rrna species (mr 0.75 x 10(6] is larger than i ...19836353227
plasmodium berghei: influence on granulopoiesis and macrophage production in balb/c mice.granulocyte and macrophage progenitor cells forming colonies in vitro (gm-cfc) from bone marrow, spleen, and peripheral blood of balb/c mice infected with plasmodium berghei were cultured at various times postinfection in a viscous, 0.8% methylcellulose system. the numbers of gm-cfcs from bone marrow increased gradually during the first week of infection, reaching a maximum around the tenth day of the disease. subsequently, a rise of gm-cfcs in cultures of nucleated cells from the peripheral blo ...19836352322
enhanced ca2+ uptake by mouse erythrocytes in malarial (plasmodium berghei) infection.erythrocytes from plasmodium berghei-infected mice on incubation either in plasma or artificial isotonic media showed an increase in uptake of 45ca2+ compared with erythrocytes from uninfected mice. infected cells (55% parasitaemia) incubated in plasma from normal or infected mice gave uptake rates of 9.8 and 8.1 nmol h-1 per 10(10) cells, assuming equilibrium between added 45ca2+ and plasma ca2+. uptake rates of erythrocytes from infected mice were increased in the presence of glucose, with a r ...19836350870
isolation and characterization of membrane proteins of plasmodium berghei sporozoites.two immunologically significant proteins, sp53 and sp110, have been isolated from the sporozoites of plasmodium berghei anka strain using different extraction procedures. in gel filtration studies the physicochemical characteristics of sp53 and sp110 appeared to be somewhat different. both polypeptides could be purified using sephacryl s300 column chromatography. the possible relationship of both sp53 and sp110 with sporozoite proteins described by other investigators is discussed.19836350869
arylmethanol and thiosemicarbazone influence of plasmodial macromolecular synthesis and cell stability.the influence of mefloquine and additional antimalarial drugs on (3h)adenosine uptake, macromolecular synthesis, and cell stability was determined in rodent red cells parasitized with plasmodium berghei. high arylmethanol to cell ratios induced lysis, whereas inhibition of macromolecular synthesis occurred at lower drug/cell ratios. a 2-acetylpyridine thiosemicarbazone rapidly suppressed (3h)adenosine uptake, and also blocked macromolecular synthesis by parasitized cells.19836350781
antibody-independent immunity to reinfection malaria in b-cell-deficient mice.immunity to "reinfection malaria" or "premunition" was studied in b-cell-deficient mice which had previously experienced acute malaria caused by the avirulent plasmodia plasmodium yoelii or p. chabaudi or by the lethal p. vinckei. such mice resisted challenge infection with large numbers of homologous parasites but differed in their capacity to resist challenge with heterologous species. mice immune to p. yoelii resisted infection with p. chabaudi but developed acute-type, albeit nonlethal, infe ...19836350181
immune phagocytosis of plasmodium berghei parasites by mononuclear phagocytes. 19836349830
conversion of glucose of lactate by intraerythrocytic plasmodium berghei.there have been many reports that intraerythrocytic plasmodium berghei does not metabolize glucose completely to lactate. however, it appears that in some circumstances there can be interference with the assay of lactate. correction by a dilution method suggests that in reality conversion is essentially complete.19836349559
entry of plasmodium berghei sporozoites into cultured cells, and their transformation into trophozoites.the attachment and entry of plasmodium berghei sporozoites to cultured human lung fibroblast (wi38) or hepatoma (hepg2-a16) cells in vitro has been visualized using an immunoperoxidase technique coupled with light microscopy. attachment and entry was substantially more frequent with hepg2-a16 cells, and appeared to be mediated by the pb44 sporozoite surface protective antigen. when sporozoites were incubated with intact monoclonal antibodies to pb44 or their monovalent fab fragments, attachment ...19836349398
in vitro cultivation of the exoerythrocytic stage of plasmodium berghei in a hepatoma cell line.when inoculated with sporozoites of plasmodium berghei, a line of hepatoma cells (hepg2-a16) derived from human liver supports the complete asexual developmental cycle of the exoerythrocytic stage. parasites were shown to resemble parasites in vivo in hepatocytes. subinoculation of merozoites into mice induced a red blood cell infection.19836349397
malaria parasites adopt host cell superoxide dismutase.aerobic organisms depend on superoxide dismutase to suppress the formation of dangerous species of activated oxygen. intraerythrocytic stages of the malaria parasite exist within a highly aerobic environment and cause the generation of increased amounts of activated oxygen. plasmodium berghei in mice was found to derive a substantial amount of superoxide dismutase activity from the host cell cytoplasm. plasmodia isolated from mouse red cells contained mouse superoxide dismutase, whereas rat-deri ...19836348944
antilymphocyte autoantibody in lethal mouse malaria and its suppression by non-lethal malaria.mice infected with lethal p. berghei or p. yoelii malaria develop anti-lymphocyte autoantibodies less than a week after infection. the autoantibodies are igm, t-dependent and cytotoxic to a subpopulation of non-t lymphocytes at 37 degrees c in the presence of mouse or guinea-pig complement. non-lethal p. yoelii and p. chabaudi do not induce these autoantibodies. x-irradiated p. berghei parasites induce autoantibodies in normal mice but not in mice infected with non-lethal p. yoelii suggesting an ...19836346230
[studies on synthetic antimalarials. vi. the synthesis and antimalarial activity of some new piperaquine analogues , tripiperaquines]. 19836344554
an ultrastructural study on the role of kupffer cells in the process of infection by plasmodium berghei sporozoites in rats.the interactions in vivo between plasmodium berghei sporozoites and kupffer cells in rat livers were studied by transmission electron microscopy. by 10 and 15 min after inoculation, sporozoites were both free in the liver sinusoids and inside endocytotic vacuoles of the kupffer cells. the latter cells were very active in phagocytosing sporozoites, bacteria and red blood cells. the sporozoites retained their integrity inside the endocytotic vacuoles and no signs of lysosomal digestion were observ ...19836343960
free-flow electrophoretic separation of plasmodium berghei sporozoites.sporozoites of the rodent malaria, plasmodium berghei, were obtained from infected anopheles stephensi by grinding mosquitoes, prepurifying the material in a discontinuous hypaque gradient and further purifying by means of continuous free-flow electrophoresis. bacteria, debris, mitochondria, mitoplasts, and other contaminants were removed in the electric field. the isolated sporozoites were morphologically intact and were positive in indirect immunofluorescence assay. they were infective to mice ...19836343576
the influence of cell type and culture medium on the in vitro cultivation of exoerythrocytic stages of plasmodium berghei.plasmodium berghei sporozoites successfully entered and developed into exoerythrocytic schizonts in a variety of cell types cultured in vitro, but segmentation and release of merozoites was only observed in human embryonic lung cells. exoerythrocytic development was generally not influenced by the culture medium, and nctc-135 was used routinely. in vitro infectivity of p. berghei sporozoites was unaffected by the serum type used for isolation.19836343574
hematopoietic tissue in malaria: facilitation of erythrocytic recycling by bone marrow in plasmodium berghei-infected mice.in p. berghei murine malaria, parasitized erythrocytes and nonparasitized reticulocytes were concentrated in the lumen of venous sinuses of bone marrow, adherent to endothelium and to one another. merozoites maturing in erythrocytes contained in venous sinuses are so positioned against adherent reticulocytes that when they break out they can penetrate adherent reticulocytes without significant extracellular exposure. merozoites from cells not adjacent to reticulocytes would spill into the plasma ...19836343573
expression of cell-mediated antimicrobial immunity by mouse trophoblast monolayers.monolayers of mouse trophoblast cells were produced after short-term culture (two to four days) of ectoplacental cone cells derived from 7.5-day-old mouse conceptuses and were then tested for phagocytic activity. following brief intervals of coincubation with the blood stage form of plasmodium berghei, the parasite that causes rodent malaria, cultured trophoblast cells were found to phagocytose large amounts of parasitic material. in a manner similar to that of peritoneal macrophages, trophoblas ...19836343521
in vitro culture of plasmodium berghei using a new suspension system. 19836343271
host defenses in murine malaria: characteristics of protracted states of immunity to plasmodium berghei.vaccination of 8-week-old b6d2 (c57bl/6 x dba/2) mice with formalin-killed asexual erythrocytic stages of plasmodium berghei provided a capacity to survive challenge with lethal p. berghei for more than 542 days. although long-lived, this immunity did not provide a capacity to immediately neutralize parasites in a challenge; significant levels of erythrocytic infection occurred transiently after each challenge. the quality of long-lived immunity was not enhanced by an injection of live parasites ...19836343244
plasmodium berghei: diet and drug dosage regimens influencing selection of drug-resistant parasites in mice.two different diets for the host and three drug dosage regimens were used to select lines resistant to sulfadoxine and pyrimethamine from the parent strain of the rodent malaria parasite plasmodium berghei [the n (k173) strain]. a higher yield of resistance was obtained when a high parasitemia was present at the beginning of the drug pressure schedule. the development of resistance to the association of sulfadoxine plus pyrimethamine was accelerated by a relatively high para-aminobenzoic acid (p ...19836343110
t-independent macrophage changes in murine malaria.a study to investigate the participation of t cells in macrophage-mediated responses during malaria was performed in nude (nu/nu) and littermate (nu/+) mice infected with plasmodium berghei (pb). we found that in both groups of mice spleen cells suppressed the mitogenic response to lps. both nu/+ and nu/nu infected mice also showed liver macrophage activation, reflected by increased plasminogen activator release. these findings suggest that at least some of the macrophage changes during malaria ...19836342882
role of macrophage-processed antigen in a plasmodium berghei model.the present study demonstrates that malarial parasite could be processed by macrophages in vitro to release 'super antigens'. these super antigens obtained from the peritoneal macrophages were more protective than those processed by the splenic adherent cells. bcg-stimulated macrophages were also able to process the antigens efficiently and these antigens were even superior to those obtained from the unstimulated macrophages. these modified antigens were potent inducers of dfps to malarial antig ...19836341933
feeding patterns of mosquitoes (diptera: culicidae) simultaneously exposed to malarious and healthy mice, including a method for separating blood meals from conspecific hosts. 19836341591
the spleen in malaria.the mechanisms underlying splenic host defence in malaria have not been precisely defined but they include both immunological and non-immunological interactions with parasitized erythrocytes. studies of the intravascular clearance of 51cr-labelled plasmodium berghei-infected erythrocytes in the rat show that these cells are cleared predominantly by the spleen, and to a greater extent in immune than non-immune animals. transfer of hyperimmune rat serum imparted protection to challenge with p. ber ...19836341005
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