| [antimalarial activities of 25 derivatives of artemisinine against chloroquine-resistant plasmodium berghei (author's transl)]. | | 1980 | 6461175 |
| enhanced parasitization of platelets by plasmodium berghei yoelii. | in previous studies plasmodia have been found by electron microscopy within human platelets naturally infected with plasmodium vivax and within platelets of mice infected intraperitoneally with p. berghei. in both situations the number of parasitized platelets was low. an enhancement of platelet parasitization was attempted in order to study in greater detail the mechanisms and implications of such a phenomenon. various in vitro incubation mixtures of normal mouse platelets and free merozoites o ... | 1984 | 6485052 |
| protection against plasmodium berghei yoelii in chloroquine- and pyrimethamine-treated mice. | the antimalarial drugs chloroquine and pyrimethamine were observed to afford protection to mice treated with these agents. this protection was observed in mice when given a subsequent challenge infection after they had been radically cured of p. b. yoelii infection. | 1984 | 6510839 |
| the chemotherapy of rodent malaria, xxxvii. the in vivo action of two mannich bases, wr 194,965 and wr 228,258 and an 8-aminoquinoline wr 225,448. | two new mannich base antimalarials, wr 194,965 and 228,258 exhibit blood schizontocidal action against plasmodium berghei in vivo. this action is retained also against the p. berghei ns line which has a low level of resistance to chloroquine. while wr 228,258 is also active against the highly chloroquine-resistant rc line, wr 194,965 is not. both compounds show slightly reduced activity against the highly mefloquine-resistant n/1100 line. wr 225,448, an 8-aminoquinoline, is as active against blo ... | 1984 | 6532327 |
| causes of death in lethal rat malaria. | the involvement of the brain, lungs and kidneys was studied in a lethal rat malaria. lewis inbred rats were infected with plasmodium berghei k173. the disease proved fatal within 10-14 days. parasitaemia showed an increase of up to 43% parasitised red blood cells on day 10 p.i. the haematocrit decreased from 50% to 12%. the systolic blood pressure dropped from 99 to 56 mmhg. the lactate dehydrogenase activity rose to 2,543 u/l. bun and serum creatinine doubled during the course of the disease. t ... | 1984 | 6611621 |
| preparation, properties and biological activity of natural and semisynthetic urethanes of monensin. | conversion of the monovalent polyether antibiotic monensin into a series of urethane derivatives substituted at c-26 causes a ten-fold increase in the cation transporting properties of the antibiotic as well as making the resulting semisynthetic urethanes divalent ionophores. these changes must in part account for the enhanced antimicrobial activities of the urethanes. the most active derivatives are the phenylurethanes which are ten times more active in vitro against gram-positive bacteria and ... | 1983 | 6630078 |
| a plasmodium protein kinase that is developmentally regulated, stimulated by spermine, and inhibited by quercetin. | plasmodium berghei-infected murine red cells possess protein kinase activity that is associated with the isolated parasites. schizonts contain significantly higher levels of this protein kinase than the more immature forms, suggesting a relationship between this enzyme activity and parasite development. partially purified protein kinase has a km for atp of approximately 30 microms, whereas the km for gtp is approximately 300 microms and the substrate preference is phosvitin greater than casein m ... | 1983 | 6654993 |
| the malaria parasite monitored by photoacoustic spectroscopy. | noninvasive photoacoustic spectroscopy was used to study the malaria parasites plasmodium chabaudi and plasmodium berghei, their pigment, and ferriprotoporphyrin ix, which is a by-product of the hemoglobin that the parasite ingests. the results indicate that the pigment consists of ferriprotophorphyrin self-aggregates and a noncovalent complex of ferriprotoporphyrin and protein. spectra of chloroquine-treated parasites reveal in situ interaction between the drug and ferriprotoporphyrin. chloroqu ... | 1984 | 6695185 |
| role of macrophages in the pathogenesis of endomyocardial fibrosis in murine malaria. | c57b1/rij mice developed progressive endocardial oedema and extensive endocardial thrombosis with a predilection for the right half of the heart in the course of a lethal plasmodium berghei infection. chemotherapy of an ongoing infection resulted in fibrosis of affected areas. despite a close correlation between development of lesions and parasitaemia, parasitized erythrocytes were not usually present in the affected areas. macrophages might play, however, an important role in the pathogenesis o ... | 1984 | 6710575 |
| chemiluminescence response of peritoneal macrophages to parasitized erythrocytes and lysed erythrocytes from plasmodium berghei-infected mice. | the chemiluminescence response of normal mouse peritoneal macrophages to parasitized erythrocytes isolated from mice 3 weeks after infection with plasmodium berghei was examined. only 4 of 12 animals showed positive responses, whereas 8 showed negative responses. photomicrographs revealed that only in chemiluminescence-positive animals were parasitized erythrocytes attached to or phagocytized by macrophages. when lysed parasitized-erythrocyte cell suspensions were added to the peritoneal macroph ... | 1982 | 6749686 |
| virulent p. berghei malaria: prolonged survival and decreased cerebral pathology in cell-dependent nude mice. | the course of lethal plasmodium berghei infection was examined in nu/+ and t cell-deficient nu/nu balb/c mice. a rapidly fatal neurologic syndrome, including ataxia, hemiparesis, and seizures, was seen in the nu/+ mice early in the infection, whereas this syndrome was absent in the nu/nu mice. the nu/nu mice also developed anemia more slowly, had lower levels of immune complexes and total igg, and had smaller decreases in serum c3 compared with the nu/+ mice. histopathologic examination of the b ... | 1982 | 6749988 |
| fansidar prophylaxis, therapy, and immune responses in rodent malaria (plasmodium berghei). | in order to determine the effect of fansidar on plasmodial infection in mice, outbred, adult, swiss-webster mice were treated with fansidar (20 mg sulfadoxine and 1 mg pyrimethamine/kg body weight) at various intervals before and/or after inoculation with blood stages of plasmodium berghei. drug therapy resulted in cure if it was given before the parasitemia rose to 53%. oral administration of fansidar was more effective in reducing or preventing parasitemia than intramuscular injection. fatal i ... | 1982 | 6750070 |
| antimalarials. 13. 5-alkoxy analogues of 4-methylprimaquine. | a series of nuclear and side-chain analogues of 4-methylprimaquine incorporating an alkoxy group in the 5-position of the quinoline nucleus has been prepared. the compounds were tested for suppressive antimalarial activity against plasmodium berghei in mice and for radical curative antimalarial activity against plasmodium cynomolgi in the rhesus monkey. although the toxicity problems characteristic of the 8-aminoquinolines were not overcome, several of the compounds, surprisingly, were highly ef ... | 1982 | 6750123 |
| the chemotherapy of rodent malaria xxxiii. the activity of chloroquine and related blood schizontocides and of some analogues in drug-induced pigment clumping. | | 1982 | 6751248 |
| plasmodium berghei: uptake and distribution of chloroquine in infected mouse erythrocytes. | | 1982 | 6751843 |
| inhibition by cyclosporin a of rodent malaria in vivo and human malaria in vitro. | the development and course of normally lethal parasitemias in mice inoculated intraperitoneally with erythrocytic stages of plasmodium yoelii or plasmodium berghei were markedly affected by treatment with the antilymphoid drug cyclosporin a (cs-a). when the first of four daily subcutaneous 25-mg/kg doses of cs-a was given at the time of parasite inoculation, patent infections failed to develop. if begun up to 5 days earlier, this same treatment regimen prolonged the prepatent period, attenuated ... | 1982 | 6752020 |
| plasmodium berghei malaria: blockage by immune complexes of macrophage receptors for opsonized plasmodia. | immune complexes produced in vitro by mixing immune serum and soluble plasmodium berghei antigens and immune complexes precipitated from serum of acutely infected rats blocked macrophage receptor sites for opsonized plasmodia. the immune complexes were precipitated from acute-phase serum, using polyethylene glycol, and their composition was determined by using a raji cell immunofluorescence assay. the immune complexes contained immunoglobulin g (igg), igm, and malarial antigens. these results in ... | 1982 | 6752023 |
| differential sensitivity in vivo of lethal and nonlethal malarial parasites to endotoxin-induced serum factor. | sera from mice infected with plasmodium yoelii or plasmodium berghei and given endotoxin contained nonspecific mediators which killed both species of parasite and tumor cells in vitro. the sera resembled tumor necrosis sera obtained from mice given macrophage-activating agents such as propionibacterium acnes (formerly designated corynebacterium acnes) or mycobacterium bovis bcg and then endotoxin. cytotoxicity developed parallel to parasite killing activity and indicated that macrophages were ac ... | 1982 | 6752029 |
| direct infection of hepatocytes by sporozoites of plasmodium berghei. | to identify the unknown liver cell type initially invaded by sporozoites of mammalian malaria, young rats were inoculated intravenously with large numbers of plasmodium berghei sporozoites obtained from infected anopheles stephensi mosquitoes. fine structural studies of liver specimens obtained from the rats within 2 min after inoculation demonstrated the presence of morphologically unaltered sporozoites in the cytoplasm of hepatocytes. many sporozoites were also observed undergoing cytolysis wi ... | 1982 | 6752394 |
| the demonstration of plasmodium berghei sporozoites in rat hepatocytes one hour after inoculation. | | 1982 | 6753390 |
| cellular changes in bone marrow of malaria-infected mice. iii. chemotaxis of granulocytes. | the number of bone marrow cells and their chemotactic activity was studied during malaria infection. two days after infection of balb/c mice with plasmodium berghei, an increase in granulocyte number was observed in the blood. a modified boyden chamber chemotaxis assay was employed to investigate the mechanism of granulocyte accumulation in the blood. bone marrow cells from normal mice, from mice during a primary lethal infection and from immune mice after challenge were compared. the complement ... | 1982 | 6753391 |
| 2-acetylpyridine thiosemicarbazones. 4. complexes with transition metals as antimalarial and antileukemic agents. | reaction of the 2-acetylpyridine thiosemicarbazones, 3-azabicyclo[3.2.2]nonane-3-thiocarboxylic acid 2-[1-(2-pyridyl)ethylidene]hydrazide (iiia), its selenium analogue (iiib), 1h-hexahydroazepine-1-thiocarboxylic acid 2-[1-(2-pyridyl)ethylidene]hydrazide (iv), and 1h-octahydroazocine-1-thiocarboxylic acid 2-[1-(2-pyridyl)ethylidene]hydrazide (v) with cu(ii), ni(ii), fe(iii), and mn(ii) salts gave crystalline complexes. relative to the free ligands, these complexes show reduced antimalarial activ ... | 1982 | 6754934 |
| susceptibility of plasmodium berghei in a laboratory population of anopheles atroparvus (diptera: culicidae) after the introduction of plasmodium-refractory genotypes. | | 1982 | 6754936 |
| ferriprotoporphyrin ix binding substances and the mode of action of chloroquine against malaria. | bovine serum albumin and preparations of cell sap from malaria parasites and normal erythrocytes were tested for ability to protect cellular membranes against the toxicity of ferriprotoporphyrin ix (fp) and a chloroquine-fp complex. suspensions of plasmodium berghei (approximately 7 x 10(6) parasites per ml, isolated from saponin-lysed, infected erythrocytes) were used as a test system. toxicity was monitored by measuring changes in turbidity of these suspensions at 700 nm. parasite cell sap (0. ... | 1982 | 6755119 |
| degenerating exo-erythrocytic forms of plasmodium berghei in rat liver: an ultrastructural and cytochemical study. | morphological and cytochemical aspects of the host response to almost mature exo-erythrocytic forms (eef) of plasmodium berghei in rat hepatocytes were studied by electron microscopy. young stages (less than 47 h) never evoked a local reaction. two types of nearly mature eef (47-51 h) could be distinguished, normal (eef type i) and those that were the target of infiltrating cells (eef type ii). the latter were in a stage of early or advanced degeneration and generally exhibited increased electro ... | 1982 | 6755366 |
| adoptive transfer of immunity to plasmodium berghei with spleen cells from drug cured mice. | plasmodium berghei infection gives rise to a fatal fulminating parasitaemia in mice. resistance to the infection can be achieved if the mice are allowed to recover from the blood-induced infection by administration of chloroquine. in cba/caj, one cycle and in balb/c mice, at least, two cycles of infection, alternating with drug-cure were necessary for the establishment of immunity. no parasitaemia was seen following further challenges after the third infection. adoptive transfer of spleen cells ... | 1982 | 6755741 |
| effect of multiple sporozoite challenges on immunity to malaria. | | 1982 | 6755744 |
| androgen suppression of circulating immune complexes and enhanced survival in murine malaria. | | 1982 | 6757933 |
| detection of exoerythrocytic stages of plasmodium berghei in fixed liver tissue and cultured cells by an immunoperoxidase antibody technique. | an immunoperoxidase antibody (ipa) technique is described for the detection of exoerythrocytic (ee) stages of plasmodium berghei in rat liver sections or cultured w138 cells. ee stages were detected in liver sections 12 hours after inoculation of sporozoites, but as early as three hours after the inoculation of w138 cells. by 42 hours in liver sections and 48 hours in w138 cells, ee parasites were easily visible by low power microscopy, and merozoites were clearly seen by 72 hours within ee para ... | 1982 | 6758221 |
| loss of infectivity for swiss mice of a mefloquine-resistant strain of plasmodium berghei. | a strain of plasmodium berghei made resistant to a 244 mg/kg daily dose of mefloquine by interrupted subcurative therapy in successive passages in weanling rats, was maintained for more than six months under drug pressure and was cryopreserved. experiments with this strain have shown its loss of virulence for intact mice. in splenectomized swiss mice infection with this resistant strain is transient. the mefloquine resistance of this line was unstable and the strain became sensitive to mefloquin ... | 1982 | 6758223 |
| [development of pyronaridine-resistance in plasmodium berghei]. | | 1982 | 6758485 |
| [synthesis of some 2, 6, 9-substituted thioguanine and their antimalarial activity]. | | 1982 | 6758486 |
| [biochemical method of determining the chloroquine resistance of p. berghei in vitro]. | | 1982 | 6759900 |
| effects of immune and hyperimmune serum on the dynamics of phagocytosis of plasmodium berghei-infected erythrocytes. | | 1982 | 6760349 |
| characterization of plasmodium berghei antigens inducing blast transformation in immune rat lymphocytes. | rat erythrocytes, infected with plasmodium berghei, were disrupted by freezing and thawing or parasites were released by mechanical breaking of the agglutinated erythrocytes. the released soluble antigens, inducing blast transformation in non-adherent immune rat spleen cells, were fractionated by a sequence of salting out, ion exchange chromatography and gel filtration. at the final step a purification factor of 83.7-fold was achieved. this fraction contained three components discernible by sds- ... | 1982 | 6760572 |
| in vitro assessment of 2-acetylpyridine thiosemicarbazones against chloroquine-resistant plasmodium falciparum. | a series of 2-acylpyridine thiosemicarbazones was evaluated in vitro against a chloroquine-resistant plasmodium falciparum strain. antimalarial activity was assessed by the inhibition of uptake of [g-3h]hypoxanthine by the parasites. among the mono- and disubstituted derivatives tested, 13 of 17 had 50% inhibitory doses of less than 10 ng/ml. increasing the size of the ring at n4 from four to five, six, and seven members produced concomitant decreases in activity. similarly, increasing the size ... | 1982 | 6760808 |
| antimalarial activity of floxacrine (hoe 991) ii: studies on causal prophylactic and blood schizontocidal action of floxacrine and related dihydroacridinediones against plasmodium yoelii and p. berghei. | | 1982 | 6760821 |
| nmr studies of malaria. 31p nuclear magnetic resonance of blood from mice infected with plasmodium berghei. | high resolution 31p-nmr has been used for the non-invasive observation of metabolites and metabolic rates in blood of normal mice and of mice infected with plasmodium berghei, the causative agent of malaria. 31p-nmr was used to quantitate levels of 2,3-diphosphoglycerate in whole cells as a function of the degree of parasitemia and yielded good agreement with the results of enzymatic assays. the time-dependence of 31p metabolites was monitored in both normal and infected erythrocytes, greater ra ... | 1982 | 6760901 |
| effect of dichroa febrifuga on plasmodium berghei. | | 1982 | 6762348 |
| [interactions of 2 associated parasitoses in the rat: plasmodium berghei and strongyloides ratti]. | when plasmodium berghei and strongyloides ratti are associated, each one of these parasites can modify development of the other one. this repercussion is subordinated to the respective periods of contamination and strength of influential parasitism. it lies in an inhibition of protozoosis or intensification of helminthiasis. when severe, palustral infection releases two hypercosticosteronemy phases; the more important one is situated at the peak of the parasitemia. these hypercorticosteronemiae ... | 1982 | 6762842 |
| adenosine triphosphate levels in mouse erythrocytes infected with chloroquine-sensitive and chloroquine-resistant plasmodium berghei. | | 1982 | 6763504 |
| [studies on piperaquine as long-acting antimalarial drug against plasmodium berghei in mice]. | | 1982 | 6763837 |
| the effect of cryopreservation on gametocytogenesis of plasmodium berghei berghei: a preliminary report. | | 1982 | 6765166 |
| [plasmodium berghei: antibody response and protective immunity induced by vaccination]. | the authors have studied the behaviour of swiss mice and of 5 inbred strains of mice in order to investigate: the protective effect, in the homologous infection test, of six vaccine inoculations of irradiated parasites belonging to two strains of plasmodium berghei: istisan and k173; the capacity to produce humoral antibodies after vaccine treatments and during infection; the probable correlation between the high antibody titre and the protection against infection. the results of the present stu ... | 1982 | 6765341 |
| the chemistry and synthesis of qinghaosu derivatives. china cooperative research group on qinghaosu and its derivatives as antimalarials. | | 1982 | 6765848 |
| the antimalarial and toxic effect of artesunate on animal models. | | 1982 | 6765851 |
| plasmodium berghei and plasmodium knowlesi: serum binding to sporozoites. | | 1980 | 6768578 |
| synthesis of 2,4-disubstituted 6-methoxy-8-aminoquinoline analogues as potential antiparasitics. | a series of 2,4-disubstituted 8-aminoquinoline analogues were synthesized and evaluated against plasmodium berghei in mice and leishmania donovani in hamsters. 8-[[6-(diethylamino)hexyl]amino]-2-ethyl-6-methoxy-4-methylquinoline (8a) possessed significant activity against l. donovani. 2-ethyl-4-methylprimaquine (7a) was evaluated against plasmodium cynomolgi in rhesus monkey and found to have activity equal to that of primaquine. | 1980 | 6770089 |
| plasmodium berghei: specific stimulation of rat lymphocytes by soluble antigens released in vitro from infected erythrocytes. | | 1980 | 6771155 |
| 4,5-disubstituted primaquine analogs as potential antiprotozoan agents. | 4,5-dimethylprimaquine and 5-fluoro-4-methylprimaquine were synthesized and evaluated against plasmodium berghei in the mouse. significant blood schizonticidal activity was observed. the 5-fluoro-4-methylprimaquine analog also was active as a tissue schizonticidal agent when evaluated against p. cynomolgi in the rhesus monkey, as an antileishmanial agent when evaluated against leishmania donovani in the hamster, and as a causal prophylactic agent when evaluated against p. berghei yoelii. | 1980 | 6772756 |
| sporozoites of mammalian malaria: attachment to, interiorization and fate within macrophages. | sporozoites of plasmodium berghei and plasmodium knowlesi, incubated in normal serum readily interact with peritoneal macrophages of mice or rhesus monkeys, respectively. interiorization of the sporozoite requires that both serum and macrophages be obtained from an animal susceptible to infection by the malaria parasite. serum requirements for sporozoite attachment to the macrophage are less specific. phagocytosis is not essential for the parasites to become intracellular. our findings indicate ... | 1980 | 6772771 |
| the protective antigen of malarial sporozoites (plasmodium berghei) is a differentiation antigen. | pb44, the protective antigen of rodent malaria sporozoite (plasmodium berghei) covers the entire surface of mature, salivary gland sporozoites. this antigen is undetectable in approximately 50% of the immature, i.e., oocyst sporozoites. on the surface of the remaining oocyst sporozoites, pb44 is found in patches. pb44 is present in early exoerythrocytic liver stages of p. berghei but is present in early exoerythrocytic liver stages of p. berghei but becomes undetectable after 30 hr of intrahepat ... | 1981 | 6785357 |
| [interaction of chloroquine with ferriprotophorphyrin ix. nuclear magnetic resonance study]. | chloroquine is still the antimalarial drug which is the most utilized. nevertheless the molecular mode of action of this drug is not very well understood. when mouse erythrocytes injected with plasmodium berghei are exposed to chloroquine, the first biochemical event is rapid accumulation of the drug. this process is energy dependent, saturable and competitively inhibited by drugs of the same therapeutic class (quinine, amodiaquine, mefloquine). receptors for chloroquine have been proposed for t ... | 1982 | 6818999 |
| inhibitory action of alpha-difluoromethylornithine on rodent malaria (plasmodium berghei). | | 1982 | 6819662 |
| a malaria 'mitogen'-induced depressed immune response to meningococcal polysaccharide vaccine in balb/c mice. | uninfected female balb/c mice were given a 4-daily intraperitoneal injection, of supernatants obtained from 24-h cultures of plasmodium berghei infected and control mouse red blood cells, for 20 days. each mouse was subsequently injected subcutaneously with 10 mg meningococcal (groups a and c combined) polysaccharide vaccine. mean meningococcal haemagglutinating antibody titres obtained in mice pretreated with control supernatants were consistently higher, than those obtained in mice pretreated ... | 1982 | 6819992 |
| killing of blood-stage murine malaria parasites by hydrogen peroxide. | both nonlethal plasmodium yoelii and lethal plasmodium berghei were killed in vitro by hydrogen peroxide at concentrations as low as 10(-5) m. higher concentrations were required in the presence of added normal erythrocytes. injection of hydrogen peroxide in vivo significantly reduced p. yoelii parasitemia but had less effect on p. berghei. | 1983 | 6822428 |
| [immunosuppressive response to antidiphtheria vaccine in animals infected by plasmodium berghei yoëlii]. | | 1980 | 6927588 |
| [immunosuppressive response to antitetanus vaccine in mice infected with plasmodium berghei yoëlii]. | | 1980 | 6927589 |
| [effect of adjuvants on the immunosuppressive effect of the parasitic action of plasmodium berghei yoëlii]. | | 1980 | 6927590 |
| dihydrofolate reductase: thymidylate synthase, a bifunctional polypeptide from crithidia fasciculata. | the molecular weight of dihydrofolate reductase (5,6,7,8-tetrahydrofolate:nadp+ oxidoreductase, ec 1.5.1.3) from protozoa has been reported to be 5- to 10-fold larger than the isofunctional enzyme of most other organisms studied, based on gel filtration. this enzyme from the protozoal flagellate crithidia fasciculata has been purified to homogeneity and found to be a bifunctional protein with thymidylate synthase (5,10-methylene tetrahydrofolate:dump c-methyltransferase, ec 2.1.1.45) activity. t ... | 1980 | 6934511 |
| immunity to plasmodium chabaudi adami in the b-cell-deficient mouse. | immunity to malaria has a multicomponent basis which requires the participation of both t- and b-lymphocyte systems. previous studies have suggested that the t-lymphocyte system has an essential role in 're-infection immunity' to malaria, but that b cells and/or their products are necessary for the host to survive acute infection and to clear the blood of parasites during chronic malaria. thus, b-cell-deficient mice and chickens died of fulminant malaria when infected with plasmodium yoelii and ... | 1981 | 6970898 |
| development of new derivatives of primaquine by association with lysosomotropic carriers. | on the basis of the drug-carrier concept of chemotherapy, we entrapped primaquine in liposomes, and linked it to an amino acid (leucine), and to peptides (alanyl-leucine and alanyl-leucyl-alanyl-leucyl) as intermediate steps in the synthesis of covalent primaquine-glycoprotein conjugates that would be selectively recognized by hepatocytes.the therapeutic activity of these compounds was tested in mice infected with sporozoites of plasmodium berghei. causal prophylatic cures were obtained after a ... | 1981 | 6976852 |
| new tissue schizontocidal antimalarial drugs. | over 700 causal prophylactic and radical curative antimalarial drugs have been discovered during the screening of approximately 4000 chemical compounds in rodent and simian malaria models. causal prophylactic activity in the plasmodium berghei-rodent model was demonstrated by 10 distinct groups of chemicals: 1) tetrahydrofolate dehydrogenase inhibitors, 2) naphthoquinones, 3) dihydroacridinediones, 4) tetrahydrofurans, 5) guanylhydrazones, 6) analogues of clopidol, 7) quinoline esters, 8) dibenz ... | 1981 | 6976854 |
| the antimalarial drug mefloquine binds to membrane phospholipids. | the new antimalarial drug mefloquine bound with high affinity (kd approximately 3 x 10-7 m) to membrane lipids of normal mouse erythrocytes and of erythrocytes infected either with chloroquine-susceptible or chloroquine-resistant plasmodium berghei. approximately 80 nmol of mefloquine was bound per mg of total lipid. mefloquine also bound to purified phospholipids with high affinity (kd approximately 3 x 10-7 m). phosphatidylinositol and phosphatidylserine bound 300 to 400 nmol of mefloquine per ... | 1982 | 6979309 |
| plasmodium berghei: premunition, sterile immunity, and loss of immunity in mice. | | 1980 | 6985593 |
| plasmodium berghei: t cell-dependent autoimmunity. | | 1980 | 6985594 |
| hybridoma produces protective antibodies directed against the sporozoite stage of malaria parasite. | hybrid cells secreting antibodies against sporozoites of plasmodium berghei were obtained by fusion of plasmacytoma cells with immune murine spleen cells. the monoclonal antibodies bound to a protein with an apparent molecular weight of 44,000 (pb44), which envelopes the surface membrane of sporozoites. incubation of sporozoites in vitro with antibodies to pb44 abolished their infectivity. | 1980 | 6985745 |
| resolution of acute malaria (plasmodium berghei in the rat): reversibility and spleen dependence. | six-week-old rats infected with plasmodium berghei developed a peak parasitemia of 55.2 +/- 3.1% by day 15 of infection, followed by spontaneous resolution of the infection during a process referred to as crisis. crisis was accompanied by the appearance in circulation of infected erythrocytes in which the parasites appeared abnormal ("crisis forms"). rats splenectomized at different times during the crisis period experienced a sudden increase in parasitemia, with a marked decrease in the number ... | 1980 | 6986095 |
| host defenses in murine malaria: immunological characteristics of a protracted state of immunity to plasmodium yoelii. | random-bred icr mice recovered from infection with avirulent plasmodium yoelii were challenged at various later times with virulent p. yoelii or with another species of plasmodium, p. berghei, to characterize the immunological nature of the long-term state of immunity generated in response to the avirulent infection. it was found that recovered mice resisted lethal challenge with virulent p. yoelii through at least 416 days after primary infection. however, the quality of this immunity changed a ... | 1980 | 6987179 |
| effect of selenium and dimethyl dioctadecyl ammonium bromide on the vaccine-induced immunity of swiss-webster mice against malaria (plasmodium berghei). | the results of the study described in this paper demonstrate that selenium, administered in drinking water, potentiates the protective effect of a killed plasmodium berghei vaccine for swiss-webster mice. we also report that a vaccine consisting of p. berghei antigen combined with the adjuvant dimethyl dioctadecyl ammonium bromide conferred a significantly high level of protective immunity. an additive effect was shown in that the greatest degree of protection was afforded to the group of mice m ... | 1980 | 6987181 |
| a solid-phase antibody binding-inhibition test, for the assay of plasmodium berghei antigen and antibodies, using radioiodinated protein a. | sonicated red blood cells (rbc) of rats infected with plasmodium berghei (pb) were used to coat plastic tubes with pb antigens. the antigen-coated tubes were employed to detect pb antigens and antibodies, with high efficiency. anti-pb antibodies were estimated by treating the tubes with rabbit or rat anti-pb sera and assaying the bound ig with radiolabeled staphylococcus pra. pb antigens were detected by their capacity to inhibit the binding of the anti-pb antibodies. using a rabbit-pb serum, so ... | 1980 | 6987313 |
| changes in the membrane microviscosity of mouse red blood cells infected with plasmodium berghei detected using n-(9-anthroyloxy) fatty acid fluorescent probes. | a set of n-(9-anthroyloxy) fatty acids (n = 2, 6, 9, 12, 16) have been used as fluorescent probes to examine the lipid environment at different depths in the outer membrane of normal mouse erythrocytes and red blood cells from plasmodium berghei-infected blood. fluorescent polarization experiments with normal mouse erythrocytes have demonstrated a typical gradient in microviscosity from the surface to the centre of the bilayer as a consequence of the motional properties of the c-atoms of the pho ... | 1980 | 6988766 |
| [structure dependance of antiplasmodic activity of 3-[n-(4-amidosulfonylphenyl)aminomethyl]-quinoline (author's transl)]. | | 1980 | 6989342 |
| the inhibitory effect of a drug combination on the development of mefloquine resistance in plasmodium berghei. | | 1980 | 6990883 |
| ferriprotoporphyrin ix fulfills the criteria for identification as the chloroquine receptor of malaria parasites. | | 1980 | 6990976 |
| isolation of a soluble component of plasmodium berghei which induces immunity in rats. | soluble material was obtained from sonically freed plasmodiae by three procedures. two procedures, cryo-impacting and freeze-thawing, were evaluated for their ability to disrupt the parasites and release soluble material. the soluble materials obtained by these procedures were compared to materials washed from the surfaces of sonically freed parasites. between 35 and 40% of the total parasite protein was solubilized by freeze-thawing or cryo-impacting. one cycle of freeze-thawing released nearly ... | 1980 | 6991439 |
| monovalent fragments (fab) of monoclonal antibodies to a sporozoite surface antigen (pb44) protect mice against malarial infection. | monoclonal antibodies (ig1, k) directed against a surface component of plasmodium berghei sporozoites (pb-44) confer complete protection to mice against a lethal inoculum of parasites. the degree of protection is a function of the number of parasites used in the challenge and of the antibody concentration in serum. passive transfer of 10 micrograms of antibody per mouse abolished or profoundly diminished the infectivity of 10(3) sporozoites, but much higher amounts of antibody were required for ... | 1980 | 6991628 |
| synthesis of potential inhibitors of hypoxanthine-guanine phosphoribosyltransferase for testing as antiprotozoal agents. 1. 7-substituted 6-oxopurines. | biological evidence indicates that the enzyme hypoxanthine-guanine phosphoribosyltransferase (ec 2.4.2.8) is vital for cell proliferation in malarial parasites but nonessential for mammalian cells. 7-substituted guanines and hypoxanthines in which the 7 substituent bears functional or hydrophobic groups were prepared with the aim of finding a suitably constituted compound whose resemblance to the normal substrate allows it to compete for the reversible purine binding site of hgrptase while allow ... | 1980 | 6991691 |
| the diagnosis of malaria infection using a solid-phase radioimmunoassay for the detection of malaria antigens. application to the detection of plasmodium berghei infection in mice. | a method has been devised to show that malaria parasites can be detected serologically in infected blood with a high degree of sensitivity. using a murine malaria model, parasites were demonstrated in a solid-phase radio-immunoassay which measured antibody-binding inhibition. lysed red blood cells (r.b.c.) were incubated with labelled specific antibody and were then reacted in antigen-coated tubes. the degree of inhibition of antibody binding in the tubes correlated with the level of parasitaemi ... | 1980 | 6992060 |
| immunization against rodent malaria with cryopreserved irradiated sporozoites of plasmodium berghei. | the preparation and storage of plasmodium berghei sporozoites for immunization purposes is described. the sporozoites were harvested from the salivary glands of infected mosquitoes, and maintained in cold tissue culture medium m199 with or without mouse serum. they were irradiated and frozen either at -75 degrees c or in liquid nitrogen. after various periods sporozoites were thawed and injected into a/j mice. at the end of the immunization period the animals were challenged with infective sporo ... | 1980 | 6992606 |
| purine base and nucleoside uptake in plasmodium berghei and host erythrocytes. | the absorption of 3h-labeled adenine, adenosine, hypoxanthine, and 14c-labeled inosine by normal rat erythrocytes, plasmodium bergheri-infected erythrocytes and saponin released "free parasites" was measured. the uptake of these labeled substrates by normal rat erythrocytes occurs both by diffusion and mediated transport systems. similar absorptive mechanisms for these substrates also were observed for both plasmodium berghei-infected erythrocytes and "free parasites." data from inhibition studi ... | 1980 | 6993639 |
| immunization of rats against malaria: a new model. | | 1980 | 6993642 |
| structure-activity analyzed by pattern recognition: the asymmetric case. | in classification studies in which pattern-recognition methods are used to distinguish active compounds from inactive ones, a type of data structure which we call "asymmetric" can be observed. this type of data structure can be quite common and its occurrence can have a profound effect on the classification analysis outcome. the origin of asymmetric data structure and a strategy or obtaining meaningful classification results when it is observed are discussed and illustrated with an example of ac ... | 1980 | 6993681 |
| [morphological incidences of the agglutination of the erythrocytes of healthy or infested (plasmodium berghei) mouse by various experimental immune sera (author's transl)]. | | 1980 | 6994569 |
| the chemotherapy of rodent malaria, xxxii. the influence of p-aminobenzoic acid on the transmission of plasmodium yoelii and p. berghei by anopheles stephensi. | more oocysts of plasmodium yoelii developed in anopheles stephensi if the mosquitoes received a supplement of p-aminobenzoic acid (paba) in their diet prior to their taking an infective blood meal, than in unsupplemented control insects. the optimum concentration was 0.05% paba in 10% sucrose. this effect was not observed if the blood meal was taken prior to feeding with paba. similarly, paba administered to gametocyte-carrying mice increased the numbers of oocysts developing in mosquitoes fed o ... | 1980 | 6994664 |
| liver xanthine oxidase increase in mice in three patholgoical models. a possible defence mechanism. | | 1980 | 6994748 |
| xanthine oxidase increase in polymorphonuclear leucocytes and macrophages in mice in three pathological situations. | | 1980 | 6994749 |
| depressed malarial immunity in pregnant mice. | a proportion of mice solidly immune to the rodent malaria parasite plasmodium berghei exhibited a pregnancy-associated depressed immunity with a transient or even lethal recrudescence. | 1980 | 6995314 |
| host responses induced in mice by a radiation-attenuated plasmodium berghei (nk65) malaria parasite. | | 1980 | 6995369 |
| distribution of chloroquine in normal, pronase-treated and malaria-infected red cells. | | 1980 | 6995763 |
| 10-hydroxy-3,4-dihydroacridine-1,9(2h,10h)-diones, a new group of malaricidal and coccidiostatic compounds. | 2-nitrobenzaldehydes and 1,3-cyclohexanediones condense in a mixture of hydrochloric acid and glacial acetic acid to 10-hydroxy-3,4-dihydroacridine-1,9(2h,10h)-diones. many compounds of this group reveal a pronounced coccidiostatic and malaricidal effect in vivo even against drug-resistant malaria parasites. synthesis and chemotherapeutic results as well as structure-activity relationships are described. | 1980 | 6998488 |
| enhanced fusion capacity of malaria (plasmodium berghei)-infected mouse red cells. | the capacity of normal and malaria-infected mouse red cells to undergo fusion was investigated by phase contrast microscopy. the fusion of mouse red cells induced by 50% w/w poly(ethylene glycol)-6000 in the presence of ca+2 is enhanced by p. berghei infection. cells carrying parasites in the ring form stage and early trophozoite stage show slightly higher fusion induced by dimethyl sulphoxide and ca+2 than those carrying parasites in trophozoite and schizont stages. | 1980 | 6998573 |
| cold isohaemagglutinins in plasmodium berghei-infected rats reacting with parasitized reticulocytes. | significant levels of cold igm and igg isohaemagglutinins were detected in the serum of rats infected with plasmodium berghei ksp 11. peak titres occurred 15 days after initial infection at the time when the parasitaemia was dropping rapidly, or 7 days after a second challenge infection. infected reticulocytes were much more sensitive to agglutination than uninfected cells, but absorption experiments demonstrated isoantigenicity in the determinants involved. this result indicated that the presen ... | 1980 | 6998593 |
| binding of antimalarial drugs to hemozoin from plasmodium berghei. | chloroquine, quinacrine and mefloquine bind to plasmodium berghei hemozoin, hemin, hemi, protoporphyrin ix and protease digested methemoglobin. this binding may be the basis for drug accumulation and action in the parasite. | 1980 | 6998717 |
| cellular changes in the bone marrow of plasmodium berghei-infected mice. ii. blast transformation and phagocytosis. | | 1980 | 7000373 |
| endotoxin in human and murine malaria. | | 1980 | 7001682 |
| culture of the liver stages (exoerythrocytic schizonts) of rodent malaria parasites from sporozoites in vitro. | | 1980 | 7001683 |
| biosynthesis of uridine monophosphate in plasmodium berghei. | high activities of the enzymes orotate phosphoribosyltransferase and orotidylate decarboxylase, that convert orotic acid to uridine monophosphate, have been demonstrated in crude supernatants obtained from lysed plasmodium berghei. the enzymes are inhibited in vitro by 5-azaorotate, 5-azauracil and 6-azauracil. of these, 5-azaorotate was the most effective and could serve as the prototype of a potential antimalarial. | 1980 | 7002072 |
| induction of cell-mediated responses against malarial erythrocytic stage through chemically pre-treated burkitt lymphoma tumour cells. | | 1980 | 7002309 |
| molecular complexes of quinoline antimalarials with iron-porphyrin components of protease-digested methemoglobin. | chloroquine, quinine, mefloquine and quinacrine have been found by difference spectroscopy to interact with hemozoin from plasmodium berghei, trypsin and pronase-digested methemoglobin, hemin, heme, protoporphyrin ix and hematoporphyrin. these drugs also compete with one another in their binding to hemin. it is proposed that the iron-porphyrin moiety of digested hemoglobin is a common binding site for the accumulation of the schizontocidal drugs in the autophagosomes of the malarial parasite. | 1980 | 7002334 |