Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| human telomeres contain at least three types of g-rich repeat distributed non-randomly. | using a combination of different oligonucleotides and restriction enzymes we have examined the gross organisation of repeats within the most distal region of human chromosomes. we demonstrate here that human telomeres do not contain a pure uniform 6 base pair repeat unit but that there are at least three types of repeat. these three types of repeat are present at the ends of most or all human chromosomes. the distribution of each type of repeat appears to be non-random. each human telomere has a ... | 1989 | 2664709 |
| therapeutic effect of chloroquine(cq)-containing immunoliposomes in rats infected with plasmodium berghei parasitized mouse red blood cells: comparison with combinations of antibodies and cq or liposomal cq. | the potential therapeutic application of chloroquine-containing immunoliposomes (fab'-lipcq) in a plasmodium berghei malaria model was studied. extending a previously described in vivo model (peeters et al. (1988) biochim. biophys. acta 943, 137-147) it was demonstrated that injection of antimouse red blood cell (anti-mrbc) fab'-lipcq was significantly more effective than liposome-encapsulated chloroquine (lipcq) or free chloroquine in delaying or preventing a patent infection after intravenous ... | 1989 | 2659088 |
| antimalarial properties of ebselen. | the seleno-organic compound ebselen showed anti-malarial activity in vitro against the murine plasmodium berghei and the human p. falciparum. in p. berghei, the uptake and incorporation of [3h]-methionine and [3h]-adenosine was inhibited and the infectivity of plasmodia was reduced. ebselen affects the development of asexual stages of chloroquine-resistant and -sensitive p. falciparum strains. its ic50 for p. falciparum was about 14 mumol/l and that for p. berghei, about 10 mumol/l. the growth o ... | 1989 | 2657716 |
| metacyclic neutralizing effect of monoclonal antibody 10d8 directed to the 35- and 50-kilodalton surface glycoconjugates of trypanosoma cruzi. | it was shown in this work that the infectivity of metacyclic forms of trypanosoma cruzi was affected upon interaction with the monoclonal antibody (10d8), which reacts with a carbohydrate epitope of the 35- and 50-kilodalton (kda) surface glycoconjugates. the invasion of vero cells by metacyclic forms of strains tulahuen and g was inhibited 50 to 67% in the presence of 10d8 (10 micrograms/ml), whereas a nonrelated monoclonal antibody to plasmodium berghei had no such effect. in mice that were in ... | 1989 | 2656520 |
| relations between resistance to chloroquine and acidification of endocytic vesicle of plasmodium berghei. | in order to visualize low-ph compartments of plasmodium berghei strains we have used a basic congener of dinitrophenol, 3-(2,4-dinitroanilino)-3'-amino-n-methyldipropylamine (damp) which concentrates in acidic compartments, and can be detected by immunocytochemistry with anti-dinitrophenol antibodies. we have demonstrated that in a p. berghei chloroquine-sensitive strain (n strain), damp accumulates in the endocytic vacuoles where haemoglobin degradation is occurring. these compartments which ha ... | 1989 | 2654832 |
| soluble malarial antigens are toxic and induce the production of tumour necrosis factor in vivo. | heat-stable soluble products of rodent malarial parasites induce activated peritoneal macrophages to secrete tumour necrosis factor (tnf) in vitro. since heat-stable parasite antigens are known to be present in the circulation of patients with malaria and it has been suggested that much of the pathology of malaria is due to tnf, we investigated the ability of such antigens to induce the production of tnf in vivo and to be toxic to mice. injection of antigens obtained from plasmodium yoelii or fr ... | 1989 | 2654012 |
| in vitro and in vivo activities of atalaphillinine and related acridone alkaloids against rodent malaria. | thirty acridone alkaloids obtained from citrus, glycosmis, or severinia plants (members of the family rutaceae) were tested for their antimalarial activities in vitro and in vivo. at a concentration of 10 micrograms/ml in vitro, seven of these alkaloids suppressed 90% or more of plasmodium yoelii, which causes malaria in rodents. atalaphillinine, when injected intraperitoneally in a daily dose of 50 mg/kg for 3 days into mice infected with 10(7) erythrocytes parasitized with plasmodium berghei o ... | 1989 | 2653215 |
| plasmodium antigens external to the parasite but with the infected erythrocyte. | three plasmodium berghei exoantigens with apparent mol. wt. of 120, 31, and 13 kda, found in infected erythrocytes by immunofluorescence, are further characterized. these antigens, synthesized in the late trophozoite and schizont stages, were released into the culture medium after schizont-infected erythrocytes were placed in culture; however, they were not found in the sera of infected animals. the 120-kda antigen proved to be somewhat heat-stable, whereas the other two did not. a monoclonal an ... | 1989 | 2652137 |
| use of chitinase to facilitate detection of protozoan, helminth and single copy genes in squashed whole mosquitoes. | the application of dna probes to detect foreign dna in whole arthropods has been limited by the inability of the probes to distinguish between small quantities of target dna and the background signal generated by non-specific hybridization of mosquito material. we report that treatment of nitrocellulose filters upon which mosquitoes have been squashed with chitinase and proteinase k eliminates non-specific hybridization of dna probes to mosquito components. using this technique we have been able ... | 1989 | 2651922 |
| molecular karyotyping of the rodent malarias plasmodium chabaudi, plasmodium berghei and plasmodium vinckei. | the molecular karyotypes of four isolates of plasmodium chabaudi, three of the subspecies p. chabaudi adami and one p. chabaudi chabaudi, as well as p. berghei and p. vinckei were studied by means of pulsed field gradient (pfg) gel electrophoresis. each species appears to have 14 chromosomes, ranging in size from approximately 730 kb to greater than 2000 kb. the three p. chabaudi adami isolates did not appear any more similar to each other than to the p. c. chabaudi isolate. the chromosome locat ... | 1989 | 2651917 |
| involvement of tumour necrosis factor and other cytokines in immune-mediated vascular pathology. | vascular endothelial cells are actively involved in coagulation and inflammation processes and appear to represent an important element in cell-mediated immune responses. in this paper, the possible role of endothelial cells as a target for immunopathological reactions was analyzed. experimental neurovascular lesions were studied in a model of cerebral malaria, with particular attention to the role of cytokine interactions in vivo. | 1989 | 2651318 |
| inhibition of erythropoiesis by a soluble factor in murine malaria. | to study the cellular mechanisms involved in the ineffective erythropoiesis associated with malaria, an in vitro proliferative assay was used to measure the response to erythropoietin (epo) of erythroid progenitor cells from malaria-infected mice. in this assay, spleen (sp) cells from phenylhydrazine (phz)-treated mice (phz-sp), enriched for erythroid progenitor cells, respond to epo in a dose-dependent manner. despite a similar degree of anemia, sp and bone marrow (bm) cells from plasmodium ber ... | 1989 | 2651136 |
| lectin-binding sites in the midgut of the mosquitoes anopheles stephensi liston and aedes aegypti l. (diptera: culicidae). | the presence and distribution of binding sites for eight different lectins, con a, dba, hpl, lfa, rca i, sba, uea i, and wga, were compared in the midguts of plasmodium gallinaceum-infected aedes aegypti and plasmodium berghei-infected anopheles stephensi. lectins with high specificity for n-acetyl-d-glucosamine (glcnac) exhibited high binding preference for the peritrophic membrane and microvillar glycocalyx of ae. aegypti; the same structures were preferentially labeled by n-acetyl-d-galactosa ... | 1989 | 2649879 |
| plasmodium berghei: gametocyte production, dna content, and chromosome-size polymorphisms during asexual multiplication in vivo. | in this study the dna content and the karyotype of clones of plasmodium berghei, which differed in the capability to produce gametocytes, were determined. the dna content per haploid genome was established by cytofluorometric methods after staining of the haploid merozoites with dna-specific fluorescent dyes. field inversion gel electrophoresis was used to establish the number and size of the chromosomes. parasites of a high gametocyte producer clone (original hp) and a low producer clone (origi ... | 1989 | 2649389 |
| plasmodium berghei: malaria infection causes increased cardiac output in rats, rattus rattus. | thirty-two 4-week-old male wistar rats were infected with plasmodium berghei malaria. on days 12 through 14, blood volume, arterial blood pressure, right ventricular pressure, heart rate, cardiac output, stroke volume, hematocrit, and vascular resistances were determined. all of the cardiovascular parameters measured, with the exception of calculated pulmonary vascular resistance, changed progressively as the peripheral blood parasitemia increased. with a rising parasitemia, cardiac output incre ... | 1989 | 2649387 |
| immunological aspects of cerebral lesions in murine malaria. | the majority of male c57bl/rij mice died infected with plasmodium berghei early in the second week. death was closely correlated to collapse of the thermoregulation of the body, with perivascular oedema and petechial haemorrhages in the brain. mice that did not show a collapse of thermoregulation (temperature drop below 30 degrees c) and survived for more than 2 weeks after infection did not show haemorrhages. development of this syndrome (temperature below 30 degrees c; early death; haemorrhage ... | 1989 | 2649283 |
| protective immunity to malaria: studies with cloned lines of rodent malaria in cba/ca mice. iv. the specificity of mechanisms resulting in crisis and resolution of the primary acute phase parasitaemia of plasmodium chabaudi chabaudi and p. yoelii yoelii. | low numbers of parasites from cloned lines of the rodent malaria parasites, plasmodium chabaudi chabaudi as and p. yoelii yoelii a, injected into cba/ca mice produce acute but usually self-limiting infections. during crisis, i.e. 1-2 days after peak parasitaemia, 'pre-immune' mice experiencing such 'background' infections were reinfected intravenously with homologous parasites or parasites of heterologous strains or species. p. c. chabaudi as pre-immune mice controlled an as challenge with essen ... | 1989 | 2648258 |
| identification of plasmodium falciparum-infected mosquitoes using a probe containing repetitive dna. | a cloned repetitive dna sequence (rep20) was evaluated as a diagnostic probe specific for plasmodium falciparum sporozoites using experimentally infected mosquitoes squashed directly on nylon filters. head/thorax portions of mosquitoes, killed 14-16 days after ingesting p. falciparum-infected blood, gave positive signals when examined for the presence of p. falciparum sporozoite dna by hybridisation. this correlated with the number of oocysts found in a sample of the same batch of mosquitoes exa ... | 1989 | 2648141 |
| plasmodium berghei: immunosuppression of the cell-mediated immune response induced by nonviable antigenic preparations. | in this work, plasmodial antigens were examined for their ability to suppress the cellular immune response during lethal plasmodium berghei infection. splenic enlargement and the number and function of white spleen cells were assessed after injection of normal mice with irradiated parasitized erythrocytes (ipe) or with parasitized erythrocytes (pe) membranes. both ipe and pe membranes caused splenomegaly and an increase in the number of splenic white cells with concurrent alteration of the relat ... | 1989 | 2645164 |
| suppression of malaria-induced autoimmunity by immunization with cryoglobulins. | cryoglobulins obtained from malaria-infected (plasmodium berghei berghei) balb/c mice were administered intraperitoneally to naive balb/c mice. ten days or 9 months following cryoglobulin administration, the naive mice were infected with malaria. comparison of sera from cryoglobulin-treated malaria-infected mice with sera from control infected mice revealed that pretreatment with cryoglobulins resulted in (1) reduced levels of circulating immune complexes; (2) reduced levels of autoantibodies re ... | 1989 | 2642745 |
| amine peroxides as potential antimalarials. | six model amine peroxides (4-9) were synthesized as targeted antimalarial oxidants. they were approximately 1 order of magnitude more potent than tert-butyl hydroperoxide (3) in vitro against plasmodium falciparum, but like 3, they were inactive in vivo against plasmodium berghei. | 1989 | 2642554 |
| fluorescence studies on erythrocyte membrane isolated from plasmodium berghei infected mice. | the erythrocyte host cell plays a key role in the well defined developmental stages of the malarial parasite growth and propogation in the erythrocyte cycle of malaria. the host cell serves the parasites by supplying metabolites and removing the catabolites produced by the obligatory parasites. it has been observed that the plasma membrane of the infected cells show a substantially higher fluidity due to the depletion of cholesterol content from the host cell. the protein component of the membra ... | 1989 | 2622455 |
| [the pharmacokinetics of a transdermal preparation of artesunate in mice and rabbits]. | qinghaosu, also known as artemisinin and arteannuin, is a new type of antimalarial drug isolated from artemisa annua l. its low solubility in water and oil limited its widespread clinical use. artesunate (sodium dihydroqinghaosu hydrogen hemisuccinate monoester) is easily soluble in water and is used iv in the treatment of acute cerebral and malignant malaria. however, artesunate was shown to have a very short half-life when given iv in animals as well as in human beings. a transdermal dosage fo ... | 1989 | 2618677 |
| delay in emergence of mefloquine resistance in plasmodium berghei by use of drug combinations. | blood induced plasmodium berghei infection in swiss mice was exposed during successive passages to melfloquine alone or melfoquine in combination with dapsone or primaquine or erythromycin, and the level of resistance to melfoquine in four sub-lines was compared at ed90 level. treatment with mefloquine alone resulted in a 201.14 fold increase in resistance after 21 passages. use of drug combination (melfoquine + dapsone) delayed the acquisition of resistance as shown by a marginal increase of ed ... | 1989 | 2571247 |
| antihistaminic drugs that reverse chloroquine resistance in plasmodium falciparum. | 1989 | 2569137 | |
| thermal properties of red blood cells infected by malaria parasites. | three membrane thermotropic transitions at 8, 20, and 40 degrees c have been detected in human red blood cells (rbc) by using spin-labeled stearic acids. red blood cells infected in vitro by plasmodium falciparum showed the disappearance of the 8 degrees c transition and a lowering of the 40 degrees c transition to 32 degrees c. the disappearance of the 8 degrees c transition was observed in synchronized cultures of p. falciparum trophozoites as well as in mouse rbc infected in vivo by an asynch ... | 1989 | 2551720 |
| di-octyl phthalate induced altered host resistance: viral and protozoal models in mice. | 1989 | 2545652 | |
| impaired immune responsiveness in plasmodium berghei immune mice. | mice immunized against plasmodium berghei parasites by drug-controlled infection exhibited decreased immunoresponsiveness against rabbit red blood cells (rrbc). increasing rrbc antigen dose increased responsiveness, but agglutinating anti-rrbc antibodies of the igg class remained undetectable. clearance of colloidal carbon from the bloodstream of malaria-immunized mice was not different from controls. removal of all the persistent parasites from immune mice did not restore responsiveness until 1 ... | 1989 | 2531361 |
| sporozoite vaccine induces genetically restricted t cell elimination of malaria from hepatocytes. | the target of the cd8+ t cell-dependent immunity that protects mice immunized with irradiation-attenuated malaria sporozoites has not been established. immune balb/c mice were shown to develop malaria-specific, cd8+ t cell-dependent inflammatory infiltrates in their livers after challenge with plasmodium berghei sporozoites. spleen cells from immune balb/c and c57bl/6 mice eliminated hepatocytes infected with the liver stage of p. berghei in vitro. the activity against infected hepatocytes is no ... | 1989 | 2524877 |
| immune complexes in serum of rats during infection with plasmodium berghei. | large amounts of immune complexes were present in the serum of infected rats early in infection when parasitemias were low. as the infection progressed and parasitemia increased and then decreased, the amounts of immune complexes in the serum also fell. this result suggests that increased efficiency of complex clearance was an important factor in determining the levels of immune complexes in the serum. in high performance liquid chromatography (hplc), the complexes in the serum migrated as a pea ... | 1989 | 2515536 |
| antimalarial effect of hbed and other phenolic and catecholic iron chelators. | previous studies showed that deferoxamine inhibits malaria by interacting with a labile iron pool within parasitized erythrocytes. consequently, we studied the antimalarial properties of other iron-chelating drugs such as 2,3-dihydroxybenzoic acid (2,3-dhb) and its methyl ester as well as two polyanionic amines, n.n'-bis (o-hydroxybenzyl) ethylenediamine-n,n'-diacetic acid (hbed) and n,n'-ethylenebis(o-hydroxyphenylglycine) (ehpg) in rats infected with plasmodium berghei. all drugs were delivere ... | 1989 | 2508794 |
| monoclonal antibody against interferon gamma can prevent experimental cerebral malaria and its associated overproduction of tumor necrosis factor. | experimental cerebral malaria (ecm), a lethal hyperacute neurological syndrome associated with high blood levels of tumor necrosis factor, develops in genetically susceptible (cba/ca) mice 7 days after infection with plasmodium berghei anka strain. injections of neutralizing monoclonal antibody against recombinant murine interferon gamma, not later than 4 days after infection, markedly reduced the incidence of ecm and the elevation in serum levels of tumor necrosis factor. this treatment prevent ... | 1989 | 2501793 |
| immune response gene regulation of immunity to plasmodium berghei sporozoites and circumsporozoite protein vaccines. overcoming genetic restriction with whole organism and subunit vaccines. | we conducted a series of experiments to define ir gene regulation of the immune response to plasmodium berghei sporozoites and circumsporozoite (cs) protein-derived subunit vaccines. the studies demonstrated that there is no apparent genetic restriction of the capacity to develop protective immunity against a large sporozoite challenge after immunization with irradiation-attenuated p. berghei sporozoites; that the th response to (asp-pro-ala-pro-pro-asn-ala-asn)n, the predominant protective b ep ... | 1989 | 2497175 |
| improved techniques for the culture of the liver stages of plasmodium berghei and their relevance to the study of causal prophylactic drugs. | the in vitro exoerythrocytic (ee) of plasmodium berghei was compared in primary rat and mouse hepatocytes and the human hepatoma cell line hepg2. all of the cell-types supported the full maturation of ee stages, but the hepg2 cells were much more susceptible to infection than the primary rodent hepatocytes and were also the most efficient host cells. following refinement of culture techniques, the development of ee forms which is now observed in hepg2 cells closely reflects that occurring in viv ... | 1989 | 2489396 |
| the causal prophylactic activity of the novel hydroxynaphthoquinone 566c80 against plasmodium berghei infections in rats. | the influence of the novel hydroxynaphthoquinone 566c80 on exoerythrocytic development of plasmodium berghei was examined in brown norway rats. the procedure employed was designed to identify residual activity of the drug against tissue merozoites emerging into the bloodstream and to distinguish this from any observed causal prophylactic activity against the liver stages. single oral doses of 10 and 1 mg/kg of 566c80 administered 3 hours after sporozoite-inoculation were effective in preventing ... | 1989 | 2489391 |
| analysis of the sporogonic development of plasmodium falciparum and plasmodium berghei in anopheline mosquitoes. | basic knowledge of the sporogonic development of malarial parasites is crucial when evaluating the sporontocidal activity of antimalarial drugs or when determining why certain vectors are refractory to a particular parasite while others are competent vectors. we have developed a model which we have used to i) assess the sporogonic development of plasmodium berghei anka in anopheles stephensi and a. freeborni mosquitoes and ii) determine the effect of chloroquine on the sporogony of p. falciparum ... | 1989 | 2487889 |
| infradian modulation of liver nucleic acid and lipid content of adult female lewis/s rats. | infradian modulation with periods of 168 h and 120 h characterizes the rna, dna and lipid content of the liver in adult female lewis/s rats. multilinear analysis shows that the fit of an infradian cosine curve with these periods is statistically significant below the 5% level (p = 0.011; p = 0.007 and p = 0.013) and that they account for 19.0, 22.7 and 20.1% of the overall variability, respectively. | 1989 | 2484289 |
| [tumor necrosis factor (tnf) and pathology; its relationships with other cytokines]. | tumor necrosis factor (tnf) is a cytokine produced mainly by activated monocytes/macrophages. we review here data obtained in four experimental models analyzed in our laboratory: cerebral malaria, graft-versus-host disease, bcg infection, and bleomycin-induced pulmonary fibrosis. we have shown that the triggering of these pathological conditions requires activation of t lymphocytes and overproduction of tnf, since these syndromes are associated with increased production of tnf mrna and can be pr ... | 1989 | 2482541 |
| a circumsporozoite-like protein is present in micronemes of mature blood stages of malaria parasites. | we demonstrate for the first time the presence of a circumsporozoite (cs)-like protein in invasive blood stages of malaria parasites. immunogold electron microscopy using antisporozoite monoclonal antibodies localized these antigens in the micronemes of merozoites. western immunoblot and two-dimensional gel electrophoresis of mature blood stage extracts of plasmodium falciparum, p. berghei, p. cynomolgi, and p. brasilianum identified polypeptides having the same apparent molecular mass and isoel ... | 1989 | 2478385 |
| cloned cytotoxic t cells recognize an epitope in the circumsporozoite protein and protect against malaria. | protective immunity against malaria is induced by vaccination of hosts with irradiation-attenuated sporozoites. this immunity is mediated in part by neutralizing antibodies that are directed mainly against the repeat domain of the circumsporozoite protein. early experiments showed, however, that b-cell-depleted mice that are immunized with sporozoites can resist challenge, indicating that t-cell effector mechanisms may also have a role in protection. this idea was supported by the recent observa ... | 1989 | 2477703 |
| comparative evaluation of the protective effect of immune spleen cells and immune rna against plasmodium berghei. | earlier studies from this laboratory indicated that passive transfer of viable or frozen-thawed cells from spleens and lymph nodes of immune mice resulted in a significant protective immunity against plasmodium berghei in syngeneic recipients. to assess whether immune rna played a role in conferring such protection, experiments were designed wherein immune rna was isolated from immune monkeys, rats and mice and transferred to normal mice. the effect of transfer was assessed by challenging rna-pr ... | 1988 | 2476085 |
| the effects of polyamine analogues on malaria parasites in vitro and in vivo. | 1988 | 2475014 | |
| pneumocystis carinii: sequence from ribosomal rna implies a close relationship with fungi. | pneumocystis carinii is the etiologic agent of a lethal pneumonia which occurs in patients with the acquired immune deficiency syndrome (aids) and other immunocompromised hosts. the basic biochemical and genetic characteristics of p. carinii are poorly understood and its taxonomic classification as a protozoan is uncertain. to address the taxonomic question, a method was developed for the extraction of total rna from p. carinii. denaturing agarose gel electrophoresis showed the two ribosomal rna ... | 1989 | 2470612 |
| expression of the precursor of the major merozoite surface antigens during the hepatic stage of malaria. | the precursor of major merozoite surface antigens (pmmsa) and its proteolytic products are candidates for an asexual blood stage vaccine. previous authors have shown that pmmsa epitopes are expressed in the liver or exoerythrocytic (ee) stage of malaria. using plasmodium berghei, we show that the molecular weight of the liver stage pmmsa is similar to that of the blood stage and that both ee and blood stage proteins are similarly processed. in the ee stage, it was synthesized toward the end of s ... | 1989 | 2469336 |
| multiple t helper cell epitopes of the circumsporozoite protein of plasmodium berghei. | the present findings establish the lack of genetic restriction of the humoral immune response to sporozoites of plasmodium berghei, corraborating earlier observations that mice of different strains can be protected by immunization with irradiated sporozoites. most, if not all, anti-sporozoite antibodies are directed against the repetitive b cell epitope of the circumsporozoite (cs) protein. however, neither a peptide containing a dimer of this repeat (17.1), nor a peptide polymer containing mult ... | 1988 | 2464495 |
| bis(benzyl)polyamine analogs inhibit the growth of chloroquine-resistant human malaria parasites (plasmodium falciparum) in vitro and in combination with alpha-difluoromethylornithine cure murine malaria. | a number of bis(benzyl)polyamine analogs were found to be potent inhibitors of both chloroquine-resistant and chloroquine-sensitive strains of the human malaria parasite plasmodium falciparum in vitro (ic50 values = 0.2-14 microm). administration of one of the compounds, mdl 27695, which is n,n'-bis(3-[(phenylmethyl)amino]propyl)-1,7-diaminoheptane (c6h5ch2nh(ch2)3nh(ch2)7nh(ch2)3nhch2c6h5), at 10-15 mg/kg i.p. three times per day for 3 days in combination with 2% alpha-difluoromethylornithine ( ... | 1989 | 2463635 |
| a marker epitope of attenuated plasmodium berghei. | plasmodium berghei xat is an irradiation-induced, permanent attenuated derivative from high-virulence p. berghei nk65. monoclonal antibodies against xat were developed. by immunofluorescence screening, one monoclonal antibody was identified that was reactive with xat at the schizont stage but not with nk65 nor with any other stage of intra-erythrocytic development of either parasite. the monoclonal antibody precipitated a 240-kd molecule from metabolically labeled xat antigens. this molecule was ... | 1988 | 2457900 |
| breakdown of the blood-brain barrier in murine cerebral malaria. | cerebral malaria in a/j and cba/h mice infected with plasmodium berghei anka is accompanied by mononuclear cell infiltration, haemorrhage and cerebral endothelial cell damage. this damage is presumably one of the causes of the breakdown of the blood-brain barrier which was detected by measuring the movement of the dye evans blue and radioisotope labelled albumin and erythrocytes. the density of brain tissue, measured by a percoll gradient technique, was significantly reduced in mice exhibiting c ... | 1988 | 2457201 |
| ookinete antigens of plasmodium berghei. appearance on the zygote surface of an mr 21 kd determinant identified by transmission-blocking monoclonal antibodies. | zygotes and ookinetes of the rodent malaria plasmodium berghei can be enriched 50-fold, from whole blood cultures by ammonium chloride lysis. three monoclonal antibodies (moabs) raised against such enriched preparations specifically bind to a determinant of mr 21 kd as assessed by 125i-labelled goat anti-mouse igg probed immunoblots of western transfers of sds-page gels. indirect immunofluorescence indicates that the 21 kd determinant bound by specific moabs, whilst not detectable on gametocytes ... | 1988 | 2453831 |
| 5-ht, 5-hiaa and related enzymes in p. berghei infected rats. | 1987 | 2450048 | |
| plasmodium species: flow cytometry and microfluorometry assessments of dna content and synthesis. | fluorescence intensities were established by flow cytometry of different erythrocytic stages of plasmodium berghei after staining of their dna with hoechst-33258 or hoechst-33342. parasites were obtained from highly synchronized infections or in vitro cultures. most fluorescence measurements were performed using a low cost, clinical flow cytometer, equipped with a mercury arc lamp. cells infected with p. berghei could be readily distinguished from uninfected cells on the basis of hoechst-dna flu ... | 1987 | 2440713 |
| [effects of chloroquine on polyamines and nucleic acid of malaria parasites]. | 1987 | 2440236 | |
| ookinete antigens of plasmodium berghei: a light and electron-microscope immunogold study of expression of the 21 kda determinant recognized by a transmission-blocking antibody. | the expression of a 21 kda transmission-blocking determinant on the malarial parasite plasmodium berghei was studied by using the immunogold method at the light, scanning-electron and transmission-electron microscope levels. the determinant was shown to be expressed exclusively on the macrogamete and its immediate progeny the zygote, ookinete and oocyst. it is first detected on the plasmalemma two hours after the escape of the parasite from the red blood cell, reaches a maximal density on the yo ... | 1987 | 2440053 |
| host immune response and pathological expression in malaria: possible implications for malaria vaccines. | 1987 | 2438630 | |
| circumsporozoite protein of plasmodium berghei: gene cloning and identification of the immunodominant epitopes. | the gene encoding the circumsporozoite (cs) protein of the rodent malaria parasite plasmodium berghei was cloned and characterized. a cdna library made from p. berghei sporozoite rna was screened with a monoclonal antibody for expression of cs protein epitopes. the resulting cdna clone was used to isolate the cs protein gene from a lambda library containing parasite blood-stage dna. the cs protein gene contains a central region encoding two types of tandemly repeated amino acid units, flanked by ... | 1986 | 2432395 |
| [test of cross immunity in 3 strains of plasmodium berghei of different virulence in mus musculus cured of infection using thermal stress (+35 degrees c)]. | 1986 | 2428277 | |
| development of a sporozoite malaria vaccine. | 1986 | 2425647 | |
| antigen-specific and mhc-restricted plasmodium falciparum-induced human t lymphocyte clones. | we established and analyzed human t lymphocyte clones induced by crude plasmodium falciparum antigens of schizont-enriched asexual blood stages. peripheral blood mononuclear cells (pbmc) were stimulated for 6 days with antigen, and the t cell blasts were separated and were transferred to limiting dilution cultures with antigen, irradiated pbmc, and recombinant interleukin 2. the following observations were made. malaria antigen (m.ag) induced similar proportions of t blasts in pbmc from infected ... | 1986 | 2424980 |
| cytofluorimetric analysis of dna content in different life stages of plasmodium yoelii. | 1985 | 2423000 | |
| sequence of the circumsporozoite gene of plasmodium berghei anka clone and nk65 strain. | 1990 | 2406593 | |
| development of malaria parasites in mosquitoes fed with ookinetes suspended in defined media. | information concerning the specific nutritional requirements of malarial parasites developing in the mosquito host has been difficult to obtain, owing primarily to the complex nature of the blood meal that accompanies the parasites and the lack of success in culturing the complete invertebrate cycle of plasmodium in vitro. the present report describes a blood-free system for infecting mosquitoes with ookinetes of plasmodium berghei and for allowing the latter to develop into infective sporozoite ... | 1990 | 2406164 |
| plasmodium berghei: the antimalarial action of artemisinin and sodium artelinate in vivo and in vitro, studied by flow cytometry. | sodium artelinate, a new water-soluble and relatively stable derivative of artemisinin, and its parent compound were tested for their antimalarial action. experiments were done in vitro with synchronous cultures of plasmodium berghei. the inhibition of growth by different concentrations of sodium artelinate and artemisinin was determined using flow cytometry. in vivo testing was done by subcutaneous injection of each drug in mice infected with p. berghei. sodium artelinate, being stable in aqueo ... | 1990 | 2404778 |
| role of dna-binding antibodies in kidney pathology associated with murine malaria infections. | we performed a series of studies to examine the sequential development of nephritis during murine malaria infections and to define the role of dna-binding antibodies in the associated pathology. serum levels of these antibodies were assessed throughout acute and chronic malaria infections. increased levels of double-stranded dna- and single-stranded dna-binding antibodies were initially detected in mice infected with plasmodium vinckei or plasmodium yoelii nigeriensis during the middle stages of ... | 1990 | 2365456 |
| preliminary evaluation of extracts of alstonia scholaris bark for in vivo antimalarial activity in mice. | the petroleum either extract and methanol extract of the bark of alstonia scholaris were found to be devoid of antiamalarial activity in mice infected with plasmodium berghei. however, a dose-dependent improvement of conditions and delayed mortality amongst animals receiving methanol extract of a. scholaris was noticed. studies with a. constricta and alstonine shall help resolve the antimalarial status of the bark in question. | 1990 | 2345460 |
| antimalarial activity of some 4-alkylamino 2/3 methoxy-4-aminodiphenyl sulphones. | from a series of thirty six 2,3, n-substituted 4,4'-diaminodiphenyl sulphones studied for their suppressive activity in mice against blood induced erythrocytic stage of plasmodium berghei infection, six sulphones (1-6) showed 100% suppressive and curative activity at an intraperitoneal dose of 1 mg/kg x 4 days. these sulphones have been studied for their suppressive activity in still lower doses ranging from 1.0-0.25 mg/kg i.p. x 4 days and for their curative activity at 1 mg/kg i.p. x 4 days in ... | 1990 | 2292320 |
| plasmodium yoelii nigeriensis circumsporozoite gene structure and its implications for the evolution of the repeat regions. | the circumsporozoite (cs) gene encodes the most immunogenic component of the plasmodial sporozoites. the immunodominant epitope-encoding domain of the cs gene shows sequences that are repeated in tandem. a detailed analysis of the cs repeats of certain closely related malaria parasites (strains of plasmodium cynomolgi, plasmodium knowlesi, and plasmodium vivax) showed that they evolve rapidly yet are well conserved within the gene. we were interested in studying whether the cs repeats of plasmod ... | 1990 | 2290446 |
| plasma orosomucoid metabolism and susceptibility to malarial infection in rodents. | the effects of plasmodium berghei infection on liver function and plasma orosomucoid metabolism were investigated in wistar rats. infected rats with 20-25% parasitaemia manifested increased serum transaminase levels, hypoalbuminaemia and hypoproteinaemia. in spite of such indications of deranged liver function, the hepatic synthesis rate (as measured by 14c-amino acid incorporation) of seromucoids predominantly orosomucoid or alpha 1-acid glycoprotein) was increased by 73%. the circulating level ... | 1990 | 2283175 |
| non-cs pre-erythrocytic protective antigens. | three novel non-cs antigens have been identified on p. falciparum and p. berghei sporozoites and exoerythrocytic parasites. csp-2 is a sporozoite surface protein common to p. falciparum and p. berghei that elicits antibody-mediated protection, and is also found within p. berghei ee parasites. lsa is a p. falciparum ee-specific antigen localized within the parasitophorous vacuole. lsa-2 is a p. berghei ee-specific antigen, localized on the parasitophorous vacuole membrane, that protected mice to ... | 1990 | 2283163 |
| host-parasite interactions and immunity to irradiated sporozoites. | we compare and contrast the results of immunizing mice with irradiated sporozoites of plasmodium berghei and plasmodium yoelii. host genetic control of protective immunity is different in the two rodent malarias. few mouse strains are strongly protected by p. yoelii sporozoites, while all are protected by p. berghei sporozoite immunization. the role of cd8+ t cells in the protective immune response to each of these malarias varies with the strain of mouse. moreover, a single strain will use a cd ... | 1990 | 2283161 |
| irradiated sporozoite vaccine induces cytotoxic t lymphocytes that recognize malaria antigens on the surface of infected hepatocytes. | the observation that protective immunity induced by immunization with radiation attenuated plasmodium berghei and plasmodium yoelii sporozoites is dependent on cd8+ t lymphocytes in some strains of mice led us to speculate that immunization with sporozoites induces cytotoxic t lymphocytes (ctl) that recognize malaria antigens on the surface of malaria-infected hepatocytes. in this report we summarize a series of experiments that confirm this hypothesis. we first showed that when immune mice are ... | 1990 | 2283160 |
| malaria exoantigens induce tnf, are toxic and are blocked by t-independent antibody. | the production of cytokines, including tumour necrosis factor (tnf), may be involved in the pathology of malaria, as well as in protection against the parasite. we have shown that parasite exoantigens induce the secretion of tnf in vitro and in vivo and kill mice made hypersensitive to tnf. they elicit t-independent antibody that inhibits their capacity to stimulate tnf production and protects against toxicity in vivo, and those of human and rodent parasites are serologically related. their acti ... | 1990 | 2283151 |
| tnf and plasmodium berghei anka-induced cerebral malaria. | the cerebral pathology observed in plasmodium berghei anka-infected cba mice has been attributed to overproduction of tnf, the mice in which this syndrome is seen being those with the highest serum tnf levels. to investigate this further, we injected recombinant human tnf into malaria-primed mice to see if we could reproduce the cerebral changes observed in p. berghei anka infections. a range of doses, administered as a single or repeated injections, or via osmotic pumps, failed to reproduce the ... | 1990 | 2283149 |
| significance of cytokine production and adhesion molecules in malarial immunopathology. | the pathological expression in malaria infection depends largely on immunopathologic responses induced by the parasite. in the past few years, we have attempted to analyze mechanisms by which inappropriate immune response to some malarial antigens can generate major complications of malaria and particularly neurovascular lesions. to this end, we have undertaken a study aimed at a more precise definition of immunopathological parameters of malaria infection, and more particularly those involved i ... | 1990 | 2283148 |
| potentiation of immune response against malaria in immunocompromised mice through glucan as an immunoadjuvant. | untreated mice were fully immunocompetent but their treatment with various immunosuppressors rendered them immunocompromised with respect to one or the other or both limbs of immunity. both, humoral immune response or cell mediated immune response suppressed mice were only partially protected against the challenge with plasmodium berghei following their immunization. hydrocortisone treated mice, in which both types of immune responses were suppressed, were not protected against the challenge wit ... | 1990 | 2279761 |
| prevention of malaria-induced foetal abnormalities following immunization of mice with plasmodium berghei merozoite antigen. | pre-pregnancy immunization of swiss albino mice with merozoite antigen of p. berghei entrapped in multilamellar phosphatidyl choline liposomes resulted in (i) increased prepatent period, (ii) either no or low parasitaemic levels, (iii) reduced mortality, and (iv) normal foetal and placental development, upon challenge with p. berghei on 13th gestational day. the unimmunized animals which received either phosphate buffered saline or empty multilamellar phosphatidyl choline liposomes before pregna ... | 1990 | 2269510 |
| [the modelling of the multiple drug resistance of the malarial parasites. 1. the combined resistance of plasmodium berghei to chloroquine and fansidar]. | using a recurrent technique, p. berghei isolate resistant to chloroquine-fansidar combination is formed in golden hamsters. the isolate resistant to chloroquine-fansidar combination was 4 times less sensitive to chloroquine, 2 times less sensitive to fansidar and its combinations, 2 times less sensitive to sulfadoxine, 31 times less sensitive to pyrimethamine, as compared to the baseline isolate lnk65 p. berghei characterized by naturally reduced sensitivity to chloroquine. | 1990 | 2266909 |
| an antigen specific to the liver stage of rodent malaria recognized by a monoclonal antibody. | vaccines currently being evaluated against malaria are based on proteins derived from the blood, sporozoite and sexual stages. antigens from the liver stage, which is now recognized as the major target of protective sporozoite induced immunity, have received comparatively little attention. this paper describes the generation of a monoclonal antibody (moab), which recognizes an antigen specific to the liver stage of the rodent malaria plasmodium berghei. the antigen is expressed throughout liver ... | 1990 | 2255559 |
| screening of artemisia absinthium for antimalarial effects on plasmodium berghei in mice: a preliminary report. | 1990 | 2255213 | |
| [synthesis of 2-methyl-5-substituted phenoxy-primaquine and antimalarials activity]. | in searching for efficient, safe and radically curative agent and causal prophylactics for malaria, seven 2-methyl-5-substituted phenoxy-6-methoxy-8-(1-methyl-4-aminobutylamino)-quinolines (ii1-7) were synthesized and their antimalarial activities were compared with the corresponding 4-methyl substituted derivatives of primaquine. the starting material, 2-nitro-4-methoxy-5-bromo-acetanilide (iii), was prepared from p-methoxy aniline through acetylation, bromination and nitration. iii was then co ... | 1990 | 2239331 |
| low dosages of interleukin 1 protect mice against lethal cerebral malaria. | in cerebral malaria, pathological changes can be found in the brain of infected people and in the brain of plasmodium berghei-infected mice. the pathogenesis of cerebral malaria in mice is believed to be due to an immunopathological reaction giving rise to an excessive production of cytokines such as interferon gamma (ifn-gamma) and tumor necrosis factor (tnf). we find that low doses of interleukin 1 (il-1) protect mice against cerebral malaria; il-1 also inhibits parasitemia. the il-1 effect on ... | 1990 | 2230643 |
| effect of prior eradication of plasmodium berghei infection on the foetal development and parasitaemic levels under the stress of pregnancy. | pregnant mice infected on gestation day (gd) 13 with plasmodium berghei had similar rate of parasitaemia and mortality as non pregnant controls. 50% of pregnant infected mice had normal delivery, 20% had absorbed foetuses and 30% died before parturation. however, animals infected with p. berghei, treated with drugs (sulfadiazine or chloroquine) had normal foetal development. no recrudescence occurred in either of these groups of animals even under the stress of pregnancy indicating protection. p ... | 1990 | 2212635 |
| [in vitro cultivation and scanning electron microscopic observation of plasmodium berghei]. | to compare the effects of sera on the growth of plasmodium berghei, the erythrocytic stages were cultured with rat serum, human umbilical cord serum, human b-type serum, rabbit serum, calf serum and calf serum with hypoxanthine respectively. the topography of the erythrocyte and parasite cultured with calf serum were observed before and 12, 20 and 28 hours after cultivation. all of the sera used did not effectively improve the long-term culture of p. berghei, regardless of some differences in sh ... | 1990 | 2208625 |
| [combined action of pyronaridine and sulfadoxine/pyrimethamine against plasmodium berghei anka strain in mice]. | pyronaridine, a highly effective antimalarial drug, was synthesized and developed by this institute. in order to test whether the joint blood schizontocidal action of pyronaridine (pnd) and 2:1 mixture of sulfadoxine/pyrimethamine (sp) resulted in a potentiation or an additive effect, groups of p berghei anka strain-infected mice were treated with various single oral doses of pnd and sp. thin blood smears were made after 72 h and the parasitemia-negative rates were calculated. the ed50 values ob ... | 1990 | 2206014 |
| cytochrome p-450 activity in malarial parasites and its possible relationship to chloroquine resistance. | cytochrome p-450-dependent enzyme activities have been determined in malarial parasites. both plasmodium berghei and plasmodium falciparum parasites exhibited activity and these activities were greater in chloroquine resistant parasites than in sensitive strains. this enzyme activity could be induced by phenobarbitone and inhibited by specific inhibitors of the cytochrome p-450 family of enzymes. the significance of these observations in parasite drug resistance is discussed. | 1990 | 2204831 |
| malaria parasitization and hormonal imbalance in virgin mice. | the effect of the malaria parasite plasmodium berghei berghei on the estrus cycle was studied in rodents. it was observed that there was a delay at the proestrus phase of the estrus cycle. endocrinological evidence for lack of ovulation at estrus during infection was presented. although there was an elevation in the level of immune complexes and white blood cell counts, the red blood cell counts decreased as infection progressed. anal temperature recordings showed pyrexia. there was a wide diffe ... | 1990 | 2203871 |
| antimalarial activity of new water-soluble dihydroartemisinin derivatives. 3. aromatic amine analogues. | a series of artemisinin (1) derivatives containing bromo and heterocyclic or aromatic amine functions was prepared in the search for analogues with good water solubility and high antimalarial activity. treatment of dihydroartemisinin (2a) with boron trifluoride etherate at room temperature gave the key intermediate, 9,10-dehydrodihydroartemisinin (3), which, on reaction with bromine, gave the dibromide 4. the latter was condensed with amines in anhydrous ch2cl2 at less than -10 degrees c to give ... | 1990 | 2202831 |
| nucleotide status in erythrocytes of rats infected with pl. berghei. | nucleotide concentrations in erythrocytes of rats infected with plasmodium berghei were measured by ion-pair reversed-phase hplc. utp and gtp levels were higher in highly infected red blood cells obtained after density separation. the infected red blood cells possess higher hypoxanthine, adenine, and adenosine levels. | 1990 | 2201292 |
| glucose-6-phosphate dehydrogenase from plasmodium berghei: kinetic and electrophoretic characterization. | evidence is given for the existence of a parasite-specific glucose-6-phosphate dehydrogenase in plasmodium berghei by characterization of its kinetic and electrophoretic properties. after separating the parasites from infected rbc the g6pd was purified by affinity chromatography with 2'5'-adp-sepharose 4b. in cellulose acetate electrophoresis malarial g6pd significantly differs from the red cell enzyme. the subunits of the parasite-specific g6pd have a molecular weight of 55 kd in contrast to 59 ... | 1990 | 2201291 |
| role of delayed type hypersensitivity responses in protection during chronic plasmodium berghei infection as evidenced by homing of radiolabelled bone marrow cells and contact sensitivity. | a comparative study of specific and non-specific immunosuppression has been carried out in acute and chronic plasmodium berghei infected mice in an in vivo system. in our previous studies, immunosuppression during acute p. berghei infection was attributed to t lymphocytes when we studied modulation of blastogenic response of lymphocytes in an in vitro system. in the present study, delayed type hypersensitivity (dth) was evident from the homing of radiolabelled bone marrow cells into the delayed ... | 1990 | 2200902 |
| antimalarial activity of a 4',5'-unsaturated 5'-fluoroadenosine mechanism-based inhibitor of s-adenosyl-l-homocysteine hydrolase. | a 4',5'-unsaturated 5'-fluoroadenosine inhibitor of s-adenosyl-l-homocysteine hydrolase (sah hydrolase; ec 3.3.1.1), mdl 28842, was found to inhibit markedly the growth of plasmodium falciparum in vitro and plasmodium berghei in mice. inhibition of p. berghei growth was associated with a large increase in the concentration of s-adenosyl-l-homocysteine (sah) in the erythrocytes of the mice treated with mdl 28842. this increase in sah was due apparently to inhibition of the mouse erythrocyte sah h ... | 1990 | 2200410 |
| typing of southern african isolates of plasmodium falciparum using monoclonal antibodies. | antigenic diversity among 19 southern african isolates of plasmodium falciparum was demonstrated using a panel of 9 monoclonal antibodies. parasites obtained from single patients were heterogeneous. the antigen composition of 9 isolates was not stable with time in culture, particularly not with respect to 4 of the monoclonal antibodies. by the end of the investigation, 70% of isolates displayed an identical antigen pattern which was markedly different to any obtained in other parts of the world. ... | 1990 | 2200288 |
| identification of a putative plasmodium berghei (a rodent malaria parasite) reticulocyte receptor. | 1990 | 2199274 | |
| hepatic superoxide dismutase, catalase and lipid peroxidation products in mastomys natalensis infected with plasmodium berghei. | p. berghei infection in m. natalensis caused a significant reduction in the hepatic sod and catalase activities. cu-zn sod was more susceptible to infection than mn sod. the inhibition of enzyme activities was associated with marked increase in the levels of lipid peroxides, lipid hydroperoxides and conjugated dienes in infected m. natalensis. the alterations in the hepatic sod, catalase and lipid peroxides are related with the severity of infection. | 1990 | 2196223 |
| [free amino acid and synthesis of polyamines in plasmodium-berghei-infected rbc]. | the contents of free amino acids and the activity of ornithine decarboxylase in infected rbc of chloroquine-sensitive strain of plasmodium berghei(cs) were similar to those in chloroquine-resistant strain (cr). after treatment with chloroquine (10mg/kg im) no effect on the formation of free amino acids was found after 20th, but chloroquine (5mg/kg im) inhibited the enzymatic activity of the cs rbc by 79.6% whereas that of the cr by 55.7%. the contents of spermidine in cs and cr infected rbc were ... | 1990 | 2194691 |
| sexual development in malarial parasites: gametocyte production, fertility and infectivity to the mosquito vector. | using cloned lines of plasmodium berghei producing mixed asexual and sexual (clone 234l) and purely asexual (clone 233l) parasitaemias, the courses of parasitaemia, gametocytogenesis, exflagellation, ookinete production in vitro and mosquito infectivity have been followed. for clone 234l mosquito infectivity is maximal at day 3 and has ceased by day 6 post-infection. conversely, gametocytogenesis, exflagellation and ookinete production are at minimal levels at day 3 and rise to peaks between day ... | 1990 | 2194152 |
| influence of pregnancy on the course of malaria in mice infected with plasmodium berghei. | the course of malarial infection was compared in pregnant mice inoculated with plasmodium berghei at different stages of gestation. when 12-14 wk old, pregnant balb/c mice were inoculated with 1 x 10(6) of p. berghei nk65-infected red cells at gestation day 0, 2, 4, 6, 8, 10, 12, 14 or 16, the mice inoculated on gestation days 6-12 expired 6.5 days after inoculation compared to 9.5 days in non-pregnant mice. parasitemia in these pregnant mice increased rapidly on day 4 after inoculation and anem ... | 1990 | 2193152 |
| [the absence of an action of the pyrethroids deltamethrin and cypermethrin on mosquito susceptibility to the causative agent of malaria]. | mosquitos ae. aegypti and an. stephensi contact with sublethal doses of deltametrin and cypermetrin pyretroids at larval stage and in grown state, when diet includes sugar with pyretroids, had no influence on the sensitivity of survived females to malaria agents p. gallinaceum and p. berghei. mosquitos under experiment showed no obvious inhibition of the physiological condition in comparison with the control ones. | 1990 | 2191201 |
| reactive oxygen species generation by kupffer cells and blood monocytes of mice infected with plasmodium berghei and the chloroquine treatment. | generation of reactive oxygen species (ros) by blood monocytes and kupffer cells of normal and plasmodium berghei infected mice treated at different levels of parasitaemia with chloroquine, were studied. cells isolated at lower level of parasitaemia (less than 2%) produced ros within the range of normal animals, whereas ros production by the cells isolated from the animals at higher level of parasitaemia (greater than 20%), was significantly higher even without stimulation with latex particles. ... | 1990 | 2191159 |
| detection of dna sequences in plasmodium berghei by means of in situ hybridization. | a non-radioactive in situ hybridization technique, used to map unique dna sequences to plant chromosomes, has been adapted for the localization of specific dna sequences in nuclei of plasmodium berghei. after hybridization using probes labeled with biotin-11-dutp, the formed dna/dna hybrids were detected by fluorescence microscopy using a specific double-layer antibody technique. besides its high resolution, this procedure is characterized by a high sensitivity, allowing the detection of a uniqu ... | 1990 | 2190950 |
| evaluation of hepatoprotective activity of picroliv (from picrorhiza kurroa) in mastomys natalensis infected with plasmodium berghei. | administration of picroliv, a standardized fraction of alcoholic extent of picrorhiza kurroa (3-12 mg/kg/day for two weeks) simultaneously with p. berghei infection showed significant protection against hepatic damage in mastomys natalensis. the increased levels of serum glutamate oxaloacetate transaminase (got), glutamate pyruvate transaminase (gpt), alkaline phosphatase, lipoprotein-x (lp-x) and bilirubin in the infected animals were marked reduced by different doses of picroliv. in the liver, ... | 1990 | 2189829 |