| the effects of plasmodium falciparum malaria on immune control of b lymphocytes in gambian children. | children living in hyperendemic malarious regions have high immunoglobulin levels and an increased frequency of burkitt's lymphoma. in a study of gambian children which endeavours to explain these findings we showed that acute p. falciparum malaria caused spontaneous activation and growth of their b lymphocytes in vitro. a high proportion of these cells contained epstein-barr nuclear antigen (ebna). in ancillary experiments aimed at explaining these findings. cd4 helper cells from adult donors w ... | 1990 | 1972671 |
| sfii and noti polymorphisms in theileria stocks detected by pulsed field gel electrophoresis. | dnas of theileria parva parva, t. p. lawrencei, t. p. bovis and theileria mutans stocks, from kenya, uganda, zanzibar and zimbabwe were digested with either sfii or noti and analysed using contour-clamped homogeneous electric field (chef) and field-inversion gel electrophoresis (fige). the sfii-digested t. parva genomic dna resolved into approximately 30 fragments while the noti digestion produced between 4-7 bands. the summation of the sizes of sfii fragments gave an estimate of 9-10 x 10(6) ba ... | 1990 | 1972977 |
| defective in vitro production of anti-plasmodium falciparum antibodies in some malaria-immune subjects. | the cell requirements for immunoglobulin (ig) and plasmodium falciparum-specific antibody production in the presence of schizont-enriched malaria antigen (m.ag) were studied in vitro. cell donors were healthy immune adult africans and europeans who had experienced single p. falciparum acute infection. in the presence of m.ag a dose-dependent increase in polyclonal igm and igg levels was observed with t/b cell cultures from 4/4 european and from 4/14 african donors (high-ig producers). in 10/14 a ... | 1990 | 1973078 |
| emergence of mefloquine-resistant malaria in africa without drug pressure. | | 1990 | 1973246 |
| field study of cyproheptadine/chloroquine synergism in falciparum malaria. | | 1990 | 1973247 |
| efficacy of pyrimethamine/sulfadoxine in uncomplicated severe falciparum malaria in kenya. | | 1990 | 1973506 |
| generation of chromosome size polymorphism during in vivo mitotic multiplication of plasmodium berghei involves both loss and addition of subtelomeric repeat sequences. | extensive chromosome size polymorphism arises in plasmodium berghei during in vivo mitotic multiplication. size differences between homologous chromosomes involve rearrangements occurring in the subtelomeric portions while internal chromosomal regions do not contribute significantly to chromosome size polymorphism. differences in the copy number of a 2.3-kb subtelomeric repeated unit are shown to correlate with size variations, and in at least one case to account completely for the size differen ... | 1990 | 1974695 |
| survival and antigenic profile of irradiated malarial sporozoites in infected liver cells. | exoerythrocytic (ee) stages of plasmodium berghei derived from irradiated sporozoites were cultured in vitro in hepg2 cells. they synthesized several antigens, predominantly but not exclusively those expressed by normal early erythrocytic schizonts. after invasion, over half the intracellular sporozoites, both normal and irradiated, appeared to die. after 24 h, in marked contrast to the normal parasites, ee parasites derived from irradiated sporozoites continued to break open, shedding their ant ... | 1990 | 1974886 |
| reversal of drug-resistant falciparum malaria by calcium antagonists: potential for host cell toxicity. | agents capable of reversing multidrug resistance (mdr) in falciparum malaria were investigated for potentiation of chloroquine accumulation and toxicity in a cell culture system. verapamil, its analog ro11-2933, and desipramine caused a dose-dependent increase in the accumulation of chloroquine (cq) within human and mouse hepatocytes but not human lung cells. only those cells in which drug accumulation was enhanced by reversing agents reacted positively for p-glycoprotein (pgp)--the putative med ... | 1990 | 1975136 |
| treatment of malaria with sulfadoxine/pyrimethamine: note of caution. | | 1990 | 1975290 |
| halofantrine to prevent falciparum malaria on return from malarious areas. | | 1990 | 1975358 |
| prevalence of antibody to heterologous circumsporozoite protein of plasmodium vivax in thailand. | the distribution in thailand of antibody to a recently discovered variant of circumsporozoite proteins of plasmodium vivax was determined by enzyme-linked immunosorbent assay (elisa). the elisa capture antigens were a synthetic peptide of the principal variant sequence angagnqpg and a candidate p vivax vaccine that contained the predominant repeat sequence gdraa/dgqpa. serological evidence of recent inoculation with the variant was found throughout thailand and in migrants from cambodia, malaysi ... | 1990 | 1975379 |
| immunization of mice against plasmodium vinckei with a combination of attenuated salmonella typhimurium and malarial antigen. | infection with the blood stage of the malaria parasite plasmodium vinckei is uniformly lethal in mice. we found that immunization of balb/c mice with a combination of killed p. vinckei antigens and an attenuated (aroa) salmonella typhimurium strain induces high levels of protection against challenge with live p. vinckei. this is especially significant because, in our previous studies, immunization of mice with killed p. vinckei antigens and adjuvants such as bordetella pertussis, complete freund ... | 1990 | 1976114 |
| malaria chemoprophylaxis: why mefloquine? | | 1990 | 1976167 |
| pyrimidine biosynthesis in parasitic protozoa: purification of a monofunctional dihydroorotase from plasmodium berghei and crithidia fasciculata. | dihydroorotase (dhoase) catalyzes the reversible cyclization of n-carbamoyl-l-aspartate (l-ca) to l-5,6-dihydroorotate (l-dho), which is the third enzyme in de novo pyrimidine biosynthesis. the enzyme was purified from two parasitic protozoa, crithidia fasciculata (about 16,000-fold) and plasmodium berghei (about 790-fold). the c. fasciculata enzyme had a native molecular weight (mr) of 42,000 +/- 5000, determined by gel filtration chromatography, and showed a single detectable protein band on s ... | 1990 | 1976382 |
| hypoglycaemia and cerebral malaria. | | 1990 | 1976969 |
| neurological sequelae of cerebral malaria in children. | out of 604 gambian children admitted with falciparum malaria to one hospital between september and december, 1988, 308 had cerebral malaria and 203 were severely anaemic (haemoglobin less than 60 g/l). 14% of those with cerebral malaria died, as did 7.8% of those with severe anaemia. 32 (12%) of children surviving cerebral malaria had residual neurological deficit. 69 other children were admitted with clinical features strongly suggestive of cerebral malaria but with negative blood films; 16 of ... | 1990 | 1977027 |
| role of gamma interferon during infection with plasmodium chabaudi chabaudi. | a role has been proposed for inflammatory mediators such as gamma interferon (ifn-gamma) and reactive oxygen intermediates in the control of the blood stages of plasmodium organisms. it was previously shown that ifn-gamma can be detected in the plasma of mice with a primary infection by plasmodium chabaudi chabaudi (as). we found that susceptible and other resistant mouse strains produced ifn-gamma, suggesting that susceptibility is not due to a defect in ifn-gamma production. administration of ... | 1990 | 1977706 |
| tnf concentration in fatal cerebral, non-fatal cerebral, and uncomplicated plasmodium falciparum malaria. | plasma levels of tumour necrosis factor (tnf) were significantly higher in 178 gambian children with uncomplicated malaria due to plasmodium falciparum than in 178 children with other illnesses. 110 children with cerebral malaria were studied shortly after admission to hospital; 28 subsequently died. compared with the children with uncomplicated malaria, mean plasma tnf levels were twice as high in cerebral malaria survivors and ten times as high in the fatal cases. although high tnf levels were ... | 1990 | 1978068 |
| cross-resistance between mefloquine and halofantrine. | | 1990 | 1978108 |
| severe malaria in a provincial hospital in vietnam. | | 1990 | 1978136 |
| cerebral malaria in children. | cerebral malaria is a rapidly progressive encephalopathy with up to 50% mortality. a cardinal feature is the massing of red cells containing mature plasmodium falciparum within the cerebral capillaries. adhesion of these parasitised red cells to endothelium, an event which may initiate cerebral malaria, is being studied at the molecular level. however, the relevance of these studies to the pathophysiology and treatment of human cerebral malaria is uncertain. although chloroquine is still widely ... | 1990 | 1978171 |
| expression and functions of p-glycoprotein (mdr1 gene product) in normal and malignant tissues. | this paper describes the cellular and tissue distribution of p-glycoprotein (p-gp) (mdr1 gene product), the role of p-gp in vivo and immunodiagnosis of multi-drug-resistant cancers. we mainly used mrk 16 monoclonal antibody (mab) reactive with p-gp. p-gp was found to be expressed very strongly in the adrenal cortex of adults and strongly in the renal tubules of the kidney, capillary blood vessels of the brain, and also in placenta. interestingly, p-gp was not distributed in fetal and neonatal ad ... | 1990 | 1978461 |
| anti-hcv false positivity in malaria. | | 1990 | 1978891 |
| human cerebral malaria: association with erythrocyte rosetting and lack of anti-rosetting antibodies. | plasmodium falciparum isolates from 24 gambian children with cerebral malaria and 57 children with mild forms of the disease were assessed for their ability to form erythrocyte rosettes. all isolates from the children with cerebral malaria were able to form rosettes, whereas those from children with mild forms of the disease did not form rosettes, or had a significantly lower rosetting rate. plasma of children with cerebral malaria lacked anti-rosetting activity, whereas plasma of children with ... | 1990 | 1979090 |
| the effect of malaria infection on the disposition of quinine and quinidine in the rat isolated perfused liver preparation. | the effect of malaria on the disposition of quinine and quinidine was studied in livers isolated from young rats infected with merozoites of plasmodium berghei, a rodent malaria model, and non-infected controls. following bolus administration of quinine (1 mg) or quinidine (1 mg) to the 100 ml recycling perfusion circuit, perfusate was sampled (0-4 h) and plasma assayed for quinine and quinidine by hplc. higher quinine (auc:6470 +/- 1101 vs 3822 +/- 347 ng h ml-1, p less than 0.001) and quinidin ... | 1990 | 1979624 |
| antibodies to plasmodium falciparum in an indigenous population from a malaria endemic area of malaysia. | indirect fluorescent antibody (ifa) tests and enzyme-linked immunosorbent assays (elisa) were used to measure antibodies to plasmodium falciparum in an indigenous population in an area of malaysia with high malaria prevalence. the results of three surveys were analyzed to examine the relation of these serologic measures with age, parasite rate, and spleen size. for children 0-4 years old, increasing spleen size was associated with an increasing likelihood of malaria parasitemia, while for 5-9 ye ... | 1990 | 1980570 |
| malaria and its treatment in rural villages of aboh mbaise, imo state, nigeria. | we examined the malaria situation among 489 children under 5 years of age in the rural villages of aboh mbaise, nigeria, using a combination of a standard questionnaire technique and laboratory diagnosis to confirm clinical observations. the results show a high prevalence rate of 52.8% for plasmodium falciparum in this area. the geometric mean parasite density (gmpd) was 19,361.4/mm3. the proportion of children with fever and/or parasitaemia was not related to age, although the numbers in the fe ... | 1990 | 1980800 |
| the role of cd4+ t cells in the protective immune response to plasmodium chabaudi in vivo. | cd4+ t cells are an essential component of the protective immune response to plasmodium chabaudi. in order to determine whether the presence of cd4+ t cells is necessary throughout a primary infection for a protective immune response to develop mice were depleted of their cd4+ t cells in vivo by treatment with specific antibodies. removal of cd4+ t cells during the acute phase of infection renders mice incapable of clearing their infection. in contrast, removal of cd4+ t cells after this time di ... | 1990 | 1980906 |
| cellular mechanisms in immunity to blood stage infection. | we studied mechanisms of immunity to blood stage infection in the mouse malarias plasmodium vinckei and plasmodium yoelii 17x. infection with p. vinckei was uniformly lethal, whereas p. yoelii 17x caused a self-limited, nonlethal infection. transfer of immune cd4+ t cells conferred protection against p. yoelii in nude mice. previous studies by others had suggested that immunity to p. yoelii may be related to mhc class i expression on reticulocytes and found that cd8+ t cells alone transferred pr ... | 1990 | 1980907 |
| mutations with multiple independent origins in surface antigens mark the targets of biological selective pressure. | this manuscript documents the existence and importance of a small subset of mutations in plasmodium falciparum genes that continually reoccur in separated populations. here we describe how to identify recurrent mutations using a novel application of pre-existing computer programs designed to trace genealogy. perhaps the most striking example of this phenomenon occurs in the cytotoxic t-cell epitope of a malaria surface antigen, the circumsporozoite (cs) protein of p. falciparum, where identical ... | 1990 | 1980908 |
| peptide analysis of the t cell response to the malaria circumsporozoite (cs) protein. | the t cell response to the circumsporozoite (cs) protein is still not well understood. there is still not agreement on the degree of immunological non-responsiveness or even on the basic question of whether the response to native cs protein requires t cells at all. recombinant proteins and synthetic peptides are tools that are helping us learn the basics of the immune response to this protein. here, the human and murine responses to the protein are probed using these valuable research tools. the ... | 1990 | 1980909 |
| hepatic phase of malaria is the target of cellular mechanisms induced by the previous and the subsequent stages. a crucial role for liver nonparenchymal cells. | both the sporozoites and the erythrocytic stages can modulate the hepatic phase by cytokines, notably ifn-gamma, tnf and il-6, either directly or as a result of a cascade of events, and by mhc-restricted and antibody-dependent cell-mediated cytotoxicity. the role played by cd8+ t cells in inducing protective immunity against pre-erythrocytic stages is clearly established. the potential interest of triggering peptide-primed cd4+ t cells has to be considered regarding protection. indeed, cd4+ t ce ... | 1990 | 1980910 |
| recommendations for action and research from a symposium and workshop on the complications, management and prevention of malaria. the roche asian research foundation. | | 1990 | 1981632 |
| the chemotherapy of rodent malaria. xlv. reversal of chloroquine resistance in rodent and human plasmodium by antihistaminic agents. | the inherent blood schizontocidal activities of five antihistaminic compounds, cyproheptadine hydrochloride (cyp), ketotifen hydrogen fumarate (ket), pizotyline hydrogen maleate (piz), azatadine maleate (azat) and loratadine (lor) were examined against the following organisms: chloroquine-sensitive (cs) plasmodium berghei and chloroquine-resistant (cr) p. yoelii ssp. ns in mice; and cs tak 9 clone 96 and cr k1 strain of p. falciparum in vitro. chloroquine, verapamil and desipramine were used as ... | 1990 | 1981663 |
| metabolism of glutamine in erythrocytes infected with the human malaria parasite: plasmodium falciparum. | the metabolism of glutamine was studied in erythrocytes infected with plasmodium falciparum, comparatively to normal cells, in presence or not of don (6-diazo-5-oxo-l-norleucine) or acivicin, two glutamine antagonists which have been shown to inhibit the growth of p. falciparum in vitro. extracellular glutamine was partially converted into glutamate using two routes corresponding to gamma-glutamyl transpeptidase (ggt) and glutaminase activities. in cells infected with mature trophozoites, the ob ... | 1990 | 1982204 |
| malaria vaccine development: pre-erythrocytic stages. proceedings of a conference. national naval medical center, bethesda, maryland, usa, 12-15 april 1989. | | 1990 | 1982734 |
| polymorphism of the trap gene of plasmodium falciparum. | natural sequence variation of the thrombospondin related anonymous protein (trap) gene of plasmodium falciparum has been investigated by dna analysis following the polymerase chain reaction amplification, and this shows the gene to be highly polymorphic. the region containing the sequence motif trp-ser-pro-cys-ser-val-thr-cys-gly (wspcsvtcg), common to trap, the circumsporozoite protein, properdin, and thrombospondin, was invariant. elsewhere in the molecule, over 50 amino acid substitutions are ... | 1990 | 1983036 |
| emetine resistant mutants of entamoeba histolytica overexpress mrnas for multidrug resistance. | although drug therapy is critical for control of amoebiasis, little is known about mechanisms of drug resistance by e. histolytica parasites. here we tested the hypothesis that multidrug resistant (mdr) amoeba mutants, similar to mdr tumor cells, are drug resistant based upon overexpression of a p-glycoprotein pump that effluxes drugs from the cells. using primers to conserved regions of the human p-glycoprotein and the polymerase chain reaction (pcr), we identified multiple 344 base par segment ... | 1990 | 1983787 |
| failure of mefloquine prophylaxis in east africa. | | 1991 | 1984183 |
| tumor necrosis factor and severe malaria. | to investigate the relation of tumor necrosis factor-alpha (tnf alpha) to plasmodium falciparum infection, plasma tnf alpha concentrations were measured in zairian children with severe malaria, mild malaria, or other illnesses. the initial geometric mean plasma concentration of tnf alpha among 61 children with p. falciparum infection, (71 pg/ml) was higher than the level in 26 severely ill, aparasitemic children (10 pg/ml; p less than .001). among 29 parasitemic children, initial geometric mean ... | 1991 | 1984482 |
| from the centers for disease control. imported malaria associated with malariotherapy of lyme disease--new jersey. | | 1991 | 1984528 |
| effectiveness and tolerance of long-term malaria prophylaxis with mefloquine. need for a better dosing regimen. | to measure the effectiveness and tolerance of long-term malaria prophylaxis with mefloquine, the incidence of plasmodium falciparum malaria and of adverse reactions was compared in peace corps volunteers in west africa who took mefloquine every 2 weeks and in volunteers who took chloroquine phosphate weekly. mefloquine was only 63% more effective than chloroquine; the monthly incidence of p falciparum infections was one case per 100 volunteers who took mefloquine and 2.7 cases per 100 volunteers ... | 1991 | 1984534 |
| imported plasmodium falciparum malaria in american travelers to africa. implications for prevention strategies. | data from the us national malaria surveillance system were analyzed to assess characteristics of travelers who acquired plasmodium falciparum infections in africa and evaluate the impact of chloroquine resistance on the incidence of imported malaria. although the number of cases acquired in east africa has stabilized, the number of imported p falciparum infections acquired in west africa increased threefold from 1985 to 1988, and the proportion of travelers who reported failure of chloroquine pr ... | 1991 | 1984539 |
| prevention of malaria. | | 1991 | 1984542 |
| assessment of the protective value of antibodies to the plasmodium falciparum ring-infected erythrocyte surface antigen (resa): an epidemiologic study in madagascar. | the ring-infected erythrocyte surface antigen (resa), a plasmodium falciparum merozoite antigen, is a major vaccine candidate against falciparum malaria. to investigate the protective role of antibodies to resa and its 4-mer, 8-mer, and 11-mer repeated amino acid sequences under conditions of natural exposure, a case-control and a cohort study were carried out in 1988 in a rural community in madagascar where malaria reappeared recently. fifty cases with greater than 1,000 p. falciparum per micro ... | 1991 | 1985446 |
| long-term chloroquine-proguanil malaria prophylaxis in a nonimmune pediatric population. | | 1991 | 1986083 |
| initial extracellular forms of plasmodium falciparum: their ultrastructure and their definition with monoclonal antibodies. | merozoites of the erythrocytic stage of the human malaria parasite plasmodium falciparum, when placed under appropriate conditions in a culture medium with erythrocyte extract, differentiate into early trophic forms. these forms have much the same ultrastructure as rings of the same age that have developed intracellularly and have then been freed from their host cells by immune lysis. however, these forms differ in two respects: the extracellular forms have only their single plasma membrane, whe ... | 1991 | 1986385 |
| analysis of immunity induced by the affinity-purified 21-kilodalton zygote-ookinete surface antigen of plasmodium berghei. | by using affinity-purified ookinete surface antigen from the rodent malaria parasite plasmodium berghei, a transmission-blocking immunity was induced in mice. groups of mice were immunized via different routes, with total quantities of antigen ranging from 0.5 to 40 micrograms (with or without freund adjuvant). vaccination by the intramuscular route with 20 micrograms of antigen in the absence of adjuvant and boosted once with the same amount of protein induced a total transmission blockade. imm ... | 1991 | 1987051 |
| malaria. variation and vaccination. | | 1991 | 1987471 |
| still hope for malaria vaccine? | | 1991 | 1987473 |
| lipid traffic between high density lipoproteins and plasmodium falciparum-infected red blood cells. | several intraerythrocytic growth cycles of plasmodium falciparum could be achieved in vitro using a serum free medium supplemented only with a human high density lipoprotein (hdl) fraction (d = 1.063-1.210). the parasitemia obtained was similar to that in standard culture medium containing human serum. the parasite development was incomplete with the low density lipoprotein (ldl) fraction and did not occur with the vldl fraction. the lipid traffic from hdl to the infected erythrocytes was demons ... | 1991 | 1988461 |
| monoclonal, but not polyclonal, antibodies protect against plasmodium yoelii sporozoites. | one of the primary strategies for malaria vaccine development has been to design subunit vaccines that induce protective levels of antibodies against the circumsporozoite (cs) protein of malaria sporozoites. in the plasmodium yoelii mouse model system such vaccines have been uniformly unsuccessful in protecting against sporozoite-induced malaria. to demonstrate that antibodies to p. yoelii cs protein could provide protection we established a passive transfer model. passive transfer of navy yoeli ... | 1991 | 1988490 |
| trat: a powerful carrier molecule for the stimulation of immune responses to protein and peptide antigens. | a number of integral membrane proteins (imps) isolated from escherichia coli have been examined for their ability to generate serum antibody responses in the absence of adjuvant. these proteins were found to stimulate high titers of serum antibody when injected into rabbits or mice in saline. the antibody titers elicited were not significantly increased by the addition of a powerful adjuvant such as ifa. covalent conjugation of bsa, of the dnp group, and of a peptide ag from plasmodium falciparu ... | 1991 | 1988496 |
| antibodies to human t lymphotropic virus type i in a population from the philippines: evidence for cross-reactivity with plasmodium falciparum. | residents of two areas in the philippines were tested for human t lymphotropic virus type i (htlv-i): napsan, a site endemic for malaria, and a nonmalarious site, bacolod. by elisa, 30% of the 1743 napsan residents were positive. western blot immunoreactivity with two or more htlv-i proteins was present in 81% of the elisa positives; however, there was no reactivity with the env proteins. the frequency of this indeterminate immunoreactivity increased with the malaria antibody titer. none of the ... | 1991 | 1988510 |
| an iron-carboxylate bond links the heme units of malaria pigment. | the intraerythrocytic malaria parasite uses hemoglobin as a major nutrient source. digestion of hemoglobin releases heme, which the parasite converts into an insoluble microcrystalline material called hemozoin or malaria pigment. we have purified hemozoin from the human malaria organism plasmodium falciparum and have used infrared spectroscopy, x-ray absorption spectroscopy, and chemical synthesis to determine its structure. the molecule consists of an unusual polymer of hemes linked between the ... | 1991 | 1988933 |
| structural and antigenic polymorphism of the 35- to 48-kilodalton merozoite surface antigen (msa-2) of the malaria parasite plasmodium falciparum. | merozoite surface antigen msa-2 of the human parasite plasmodium falciparum is being considered for the development of a malaria vaccine. the antigen is polymorphic, and specific monoclonal antibodies differentiate five serological variants of msa-2 among 25 parasite isolates. the variants are grouped into two major serogroups, a and b. genes encoding two different variants from serogroup a have been sequenced, and their dna together with deduced amino acid sequences were compared with sequences ... | 1991 | 1990294 |
| protection against malaria morbidity: near-fixation of the alpha-thalassemia gene in a nepalese population. | we have previously reported that the tharu people of the terai region in southern nepal have an incidence of malaria about sevenfold lower than that of synpatric non-tharu people. in order to find out whether this marked resistance against malaria has a genetic basis, we have now determined in these populations the prevalence of candidate protective genes and have performed in-vitro cultures of plasmodium falciparum in both tharu and non-tharu red cells. we have found significant but relatively ... | 1991 | 1990845 |
| the effect of n-alkyl modification on the antimalarial activity of 3-hydroxypyridin-4-one oral iron chelators. | the antimalaria effect of iron chelators is attributed to their interaction with a labile iron pool within parasitised erythrocytes, and it was postulated that increased affinity to iron as well as increased lipophilicity may improve antimalarial activity. in the present study we have examined the antimalarial effect of 3-hydroxypyridin-4-ones, a family of bidentate orally effective iron chelators whose lipophilicity may be modified by altering the length of the r2 substituent on the ring nitrog ... | 1991 | 1991172 |
| l-arginine-dependent destruction of intrahepatic malaria parasites in response to tumor necrosis factor and/or interleukin 6 stimulation. | there is growing evidence that cytokines (interleukin [il] 1, il 6, interferon-gamma, tumor necrosis factor [tnf]) directly or indirectly interfere with the intrahepatic development of malaria parasites. recent work in our laboratory clearly showed that tnf can affect the hepatic development of parasites via il 6 secreted by liver nonparenchymal cells. the possible participation of an l-arginine-dependent effector mechanism has been studied to explain the tnf/il 6-induced inhibition. we thus inv ... | 1991 | 1991487 |
| from the centers for disease control. change of dosing regimen for malaria prophylaxis with mefloquine. | | 1991 | 1992177 |
| isolation and characterization of a soluble antigen complex of plasmodium falciparum with pyrogenic properties. | a soluble antigen complex, previously designated antigen no. 7 (ag7) on the basis of the pattern obtained by crossed immunoelectrophoresis of culture supernatants of p. falciparum, was isolated by affinity chromatography. it was shown to be synthesized at the schizont stage of the parasite growth cycle and to be located on the surface of the schizonts. antibodies to ag7 did not inhibit the growth of the parasite in vitro. ag7 is recognized by immune human sera from many parts of the world and it ... | 1991 | 1993114 |
| severe falciparum malaria in nonendemic areas: an unrecognized medical emergency. | | 1991 | 1993293 |
| inflammatory status and preerythrocytic stages of malaria: role of the c-reactive protein. | in the acquisition of protection against malaria, the role played by nonspecific factors, some being part of the cascade effect of cytokines, has to be considered. the c-reactive protein, a major acute phase reactant secreted by interleukin-1 stimulated hepatocytes, has an effect on the hepatic development of plasmodia, both by preventing penetration of the sporozoite into the hepatocyte and by blocking parasite division through an antibody-like effect. this latter effect confirms the potential ... | 1991 | 1993457 |
| plasmodium yoelii: quantification of the exoerythrocytic stages based on the use of ribosomal rna probes. | | 1991 | 1993458 |
| plasmodium berghei: ionic regulation and the induction of gametogenesis. | the role of ionic regulation in the induction of gametogenesis of plasmodium berghei at 20 degrees c was investigated. a potent inhibitor of na+/h+ exchange, amiloride, strongly inhibited exflagellation and subsequent ookinete formation induced by rpmi 1640 with 10% fetal calf serum at ph 8.0, whereas na+ or k+ channel inhibitors, h(+)-atpase inhibitors, and a protonophore had no significant effect. amiloride-treated 'activated' microgametocytes synthesized dna to levels consistent with the expe ... | 1991 | 1993463 |
| plasmodium cynomolgi: immunization of a rhesus monkey with exoerythrocytic stages cultured in autologous hepatocytes. | to investigate the immune response to exoerythrocytic stages of malaria parasites, a rhesus monkey was immunized with autologous primary hepatocyte cultures infected with 7-day-old liver stage parasites of plasmodium cynomolgi. a primary antibody response against ee stage antigens was obtained, and boosted after injection of homologous viable sporozoites. antibodies directed against sporozoites and blood stages were also detected. the polyvalent immune response observed demonstrates the antigeni ... | 1991 | 1993467 |
| towards the development of the ideal malaria vaccine. a decade of progress in a difficult field. | malaria remains one of the world's most serious diseases, affecting the lives of up to 500 million people. the rapid development of drug resistance enhances the need for the development of a vaccine. since the first cloning of malaria proteins early in the last decade, there have been a number of "subunit" vaccine trials involving humans and monkeys. during this time, our understanding of the basic immunobiology of malaria has increased; different immune mechanisms are required to combat the dif ... | 1991 | 1994206 |
| studies on pf155/resa and other soluble antigens from in vitro cultured plasmodium falciparum. | spent culture medium from in vitro cultures of plasmodium falciparum was used as the source for immunoadsorbent enrichment of soluble parasite antigens. igg obtained from p. falciparum-hyperimmune liberian serum was used as the ligand in the immunoadsorbent. sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) of the immunoadsorbent isolated material revealed the presence of at least 15 antigenic and parasite-derived polypeptides. immunoblotting after sds-page showed greater than ... | 1991 | 1994367 |
| flow cytometric monitoring of parasitaemia during treatment of severe malaria by exchange transfusion. | | 1991 | 1995323 |
| antimalarial polyamine analogues. | a series of novel tetraamines of the general formula rnh(ch2)xnh(ch2)ynh(ch2)xnhr was synthesized and examined for activity against growth of plasmodium falciparum in vitro. within the series, dibenzyl analogues (r = benzyl) were found to be the most effective growth inhibitors, with ic50 values of about 10(-6) m. further modifications of the tetraamine provided the optimum chain length for antimalarial activity of y = 7, x = 3. compound 8 (mdl 27,695) with the structure y = 7, x = 3, r = benzyl ... | 1991 | 1995879 |
| proguanil daily or chlorproguanil twice weekly are efficacious against falciparum malaria in a holoendemic area of tanzania. | the prophylactic efficacy of proguanil 100 mg (paludrine) daily was compared to that of chlorproguanil 20 mg (lapudrine) twice weekly in school children from nyamisathi village, in a coastal area of tanzania, 160 km south of dar es salaam. a total of 80 children were randomly allocated to three groups after radical treatment with a curative dose of mefloquine (lariam). seventy-six children were then followed up with daily prophylaxis and/or placebo for 13 weeks. all children in the group taking ... | 1991 | 1995934 |
| from the centers for disease control. mosquito-transmitted malaria--california and florida, 1990. | | 1991 | 1995962 |
| rapid microscopic detection of malaria parasites permanently fluorochrome stained in blood smears with aluminum and morin. | intra- and extracellular plasmodium parasites in fixed blood smears are easily identifiable by fluorescence microscopy after brief mordanting with aluminum ammonium sulfate and staining with morin (3,5,7,1',4'-pentahydroxyflavanol). the intensely fluorescent preparations of stained parasites are strongly resistant to photodegradation and remained essentially unimpaired for two years. | 1991 | 1996554 |
| detection of plasmodium falciparum infection with the fluorescent dye, benzothiocarboxypurine. | the fluorescent dye benzothiocarboxypurine (bcp) intensely stains nucleic acids. the dye does not penetrate viable white blood cells but does stain these cells following fixation. it has also been found that the dye stains the nucleic acid of viable plasmodium falciparum. we have subsequently evaluated the staining of p. falciparum by benzothiocarboxypurine within red blood cells and have found that the red blood cell membrane is freely permeable to this dye and consequently p. falciparum is sta ... | 1991 | 1996734 |
| acridine orange fluorescent microscopy and the detection of malaria in populations with low-density parasitemia. | detection of low-density malaria parasites with giemsa-stained thick smears (g-ts) requires time and experience and becomes impractical with high sample loads. acridine orange fluorescent microscopy (ao/fm) of capillary centrifuged blood may offer an alternative technique. we compared ao/fm readings with g-ts in 290 specimens from asymptomatic people in thai villages endemic for malaria. ao/fm specimens were prepared in modified capillary tubes coated with acridine orange (quantitative buffy coa ... | 1991 | 1996735 |
| characteristics of natural antibody responses to the circumsporozoite protein of plasmodium vivax. | the antibody response to the prototype circumsporozoite (cs) protein of plasmodium vivax (cspv) was studied in thai soldiers experiencing occupational malaria. seventy-four (65%) of 114 men followed during assignment to a malaria transmission area developed blood-stage infection with p. vivax. igg antibodies against the central repeat region of the cspv protein were quantitated by elisa using the recombinant protein, ns181v20, as the capture antigen. one quarter of the subjects had detectable an ... | 1991 | 1996736 |
| plasmodium vivax sporozoite antibodies in individuals exposed during a single malaria outbreak in a non-endemic area. | we studied seroreactivity against plasmodium vivax antigens in 62 individuals living in a small community near mantena, minas gerais, brazil, an area outside the endemic malaria zone brazil. eight months earlier, there had been transmission of p. vivax for a period of 50 days, which was then totally controlled by chemotherapy and insecticides. an anti-sporozoite response, measured by elisa using a recombinant protein expressed in yeast, was detected in 45% (14 of 31) of individuals eight months ... | 1991 | 1996737 |
| immunization of owl monkeys with the ring-infected erythrocyte surface antigen of plasmodium falciparum. | aotus nancymai were immunized with the 4-mer, 8-mer, and 11-mer repeat peptides of the ring-infected erythrocyte surface antigen molecule of plasmodium falciparum conjugated to diphtheria toxoid with muramyl dipeptide (mdp) as adjuvant. immunization failed to induce protective immunity against the uganda palo alto strain of p. falciparum as judged by maximum levels of parasitemia of immunized monkeys relative to those of controls. the fused polypeptide fpag632, when combined with mdp, also faile ... | 1991 | 1996739 |
| a spleen is not necessary to resolve infections with plasmodium yoelii. | the role of the spleen in resistance to infections with nonlethal plasmodium yoelii 17x is dependent upon the genotype of the host. thus, dba/2 (d2) mice infected with p. yoelii 17x were not adversely affected by removal of the spleen, while splenectomized c57bl/6 (b6) or balb/c mice failed to resolve their infections and eventually died. the levels of parasitemia were lower in splenectomized mice compared to intact controls; however, splenectomized mice became as anemic as did spleen-intact con ... | 1991 | 1996740 |
| increased permeability to choline in simian erythrocytes after plasmodium knowlesi infection. | the permeability of simian erythrocytes to choline was found to be considerably increased after infection by the malaria parasite, plasmodium knowlesi. choline entry occurs by a facilitated-diffusion system involving a carrier, which displays temperature-dependence, saturability with choline (km = 8.5 +/- 0.7 microm) and specificity. this carrier can also be inhibited by a thiol reagent, n-ethylmaleimide, at an inactivation rate which is, in the absence of choline, the same as in normal erythroc ... | 1991 | 1996967 |
| blood stage-induced plasmodium brasilianum infection in the squirrel monkey induces antibodies which react with the circumsporozoite protein. | a blood stage-induced p. brasilianum infection in a naive squirrel monkey induced antibodies which reacted with the circumsporozoite protein of the parasite. titers increased with duration of infection and persisted for 3 months after cure. in an immunoblot, these antibodies detected two polypeptides with molecular weights identical to those of the circumsporozoite protein and its precursor. | 1991 | 1997421 |
| plasmodium falciparum ring-infected erythrocyte surface antigen is released from merozoite dense granules after erythrocyte invasion. | electron microscopy was used to study the fate of plasmodium falciparum ring-infected erythrocyte surface antigen after merozoite invasion by using postembedding immunolabeling. the antigen was localized to small dense granules located centrally or laterally in free merozoites. in newly invaded erythrocytes, labeling was found in pockets of the parasitophorous vacuole space or in aggregates closely associated with the parasitophorous vacuole. these patterns indicate that ring-infected erythrocyt ... | 1991 | 1997422 |
| clinical correlates of in vitro plasmodium falciparum cytoadherence. | to determine whether isolates of plasmodium falciparum have intrinsically different cytoadherent properties and whether these differences contribute to the clinical severity of human falciparum malaria, we studied the cytoadherence to c32 melanoma cells in vitro of 59 parasite isolates from patients with naturally acquired infections in thailand. parasitized erythrocytes adhere to these melanoma cells principally via the glycoprotein cd36, which is also expressed on most vascular endothelium. in ... | 1991 | 1997437 |
| in vitro development of exoerythrocytic forms of plasmodium gallinaceum sporozoites in avian macrophages. | exoerythrocytic forms of plasmodium gallinaceum were cultured in vitro using salivary gland sporozoites extracted from experimentally infected aedes fluviatilis mosquitoes. the host cells were macrophage precursors from chicken bone marrow. at various times after introduction of sporozoites, the cultures were stained by giemsa or by immunofluorescence assay (ifa) using anti-sporozoite-specific monoclonal antibodies (mab). the time to complete parasite development in vitro was 50-70 h. by 70 h, r ... | 1991 | 1997676 |
| aids in africa. | | 1991 | 1997859 |
| [from malaria chemoprophylaxis to malaria self-treatment (1975-1989)]. | swissair's 3000-odd cockpit and cabin personnel spend an aggregate total of one year in the tropics for every ten years of flight service with the airline. since 1975, company policy has been to issue all crews with a 'treatment dose' of anti-malaria medication to be taken if malaria contraction is suspected. up until 1985, this treatment dose medication was recommended to crews for cases in which malaria was suspected even though chemoprophylactic medication had been taken. since 1985, crews ha ... | 1991 | 1998078 |
| [clinical aspects and diagnosis of malaria]. | malaria must be included in the differential diagnosis of all febrile patients. malaria is classified 'complicated' or 'uncomplicated', according to clinical findings (cerebral malaria, generalized convulsions, pulmonary edema, severe anemia, hyperthermia, renal failure, haemoglobinuria, shock, spontaneous bleeding) and laboratory results (parasitemia greater than 5%, haemoglobin less than 5 g%, creatinine greater than 265 mumol/l, glucose less than 2.2 mmol/l, dic, ph less than 7.2, bilirubin g ... | 1991 | 1998079 |
| [possibilities and limitations of malaria therapy in general practice]. | malaria infections by plasmodium (p.) vivax. p. ovale or p. malariae follow mostly a benign course, and ambulatory treatment is safe, provided there is no other significant morbidity. ambulatory treatment for falciparum malaria must be considered only if a number of conditions are met, making potential complications most unlikely. furthermore, it is imperative that the patient can be reliably supervised at home. taking into account the increase of p. falciparum strains resistant to chloroquine, ... | 1991 | 1998080 |
| [current drugs for the treatment of tropical malaria]. | the occurrence in the early 60's of stable resistance to chloroquine among plasmodium falciparum strains in the amazonas and on the thai-cambodian border has been a shock for all malariologists. this led to the search for new antimalarials without cross resistance with chloroquine. for each new drug, one of the major concerns was to define how rapidly parasites would develop resistance to this compound. drug combinations were taken into consideration so as to achieve a delay in the appearance of ... | 1991 | 1998081 |
| a novel detection of a single plasmodium falciparum in infected blood. | detection of plasmodium falciparum malaria by a specific dna probe is a highly promising means for epidemiological surveillance of human malaria. however, none of presently available dna probe methods could detect as little as a few parasites in infected blood. by amplification of a specific 206 base pairs p. falciparum dna sequence using the polymerase chain reaction (pcr), as little as 0.01 picogram dna or one-half of a parasite was sufficient for a specific detection. a pcr procedure for dete ... | 1991 | 1998502 |
| characteristics of 86rb+ transport in human erythrocytes infected with plasmodium falciparum. | human red cells infected in vitro with plasmodium falciparum showed a significant increase in the rate of both ouabain-sensitive and ouabain-insensitive 86rb+ influx. the increase in ouabain-insensitive 86rb+ influx was due, in part, to increased transport via a bumetanide-sensitive system and, in part to transport via a pathway that was absent (or at least inactive) in uninfected cells. the parasite-induced pathway was inhibited by piperine and had a dose response very similar to that of the ga ... | 1991 | 1998699 |
| clearing the air on malaria. | | 1991 | 1998925 |
| blocking of the receptor-mediated invasion of erythrocytes by plasmodium knowlesi malaria with sulfated polysaccharides and glycosaminoglycans. | invasion of human erythrocytes by plasmodium knowlesi requires the duffy blood group antigen. p. knowlesi merozoites synthesize a 135-kda polypeptide which binds to the duffy antigen with receptor-like specificity. in this study, we show that the sulfated polysaccharide fucoidan and the glycosaminoglycan dextran sulfate inhibit the binding of the 135-kda polypeptide to human duffy-positive and rhesus erythrocytes while the chondroitin sulfates do not. fucoidan and dextran sulphate also blocked t ... | 1991 | 1999196 |
| chloroquine-resistant plasmodium vivax from indonesia. | | 1991 | 2000121 |
| structural diversity in the plasmodium falciparum merozoite surface antigen 2. | antigens associated with the surface of merozoites of the malaria parasite plasmodium falciparum are directly accessible to immune attack and therefore are prime vaccine candidates. we have previously shown that one of the two known merozoite surface antigens (merozoite surface antigen 2; msa-2) exhibits considerable sequence and antigenic diversity in different isolates. the sequences of msa-2 from three isolates revealed a central domain composed of repeats that vary in number, length, and seq ... | 1991 | 2000383 |
| cerebral falciparum malaria mimicking thrombotic thrombocytopenic purpura. | we have described a patient with cerebral falciparum malaria who had rapidly progressive cns deterioration, renal failure, hemolytic anemia associated with striking and varied erythrocyte morphologic changes, and thrombocytopenia. the initial diagnosis was thrombotic thrombocytopenic purpura (ttp) of unknown origin. reexamination of the peripheral smear of this comatose patient led to correct diagnosis and effective treatment in this case of cerebral falciparum malaria--another of medicine's gre ... | 1991 | 2000526 |
| modification of host cell membrane lipid composition by the intra-erythrocytic human malaria parasite plasmodium falciparum. | the phospholipid and fatty acid compositions of the host infected erythrocyte plasma membrane (iepm) have been determined for erythrocytes infected with the human malaria parasite plasmodium falciparum. iepm were prepared by selective lysis of the host erythrocyte (but not of the parasite membranes) with 0.1% saponin, followed by differential centrifugation. the purity of the iepm was determined by measuring the membrane-specific enzyme markers acetylcholinesterase, glutamate dehydrogenase and l ... | 1991 | 2001227 |
| identification and localization of a soluble antigen, ag2, of 136 kda from plasmodium falciparum in vitro cultures. | the soluble antigens, antigen 2 (ag2) and antigen 6 (ag6), were copurified from supernatants of p. falciparum in vitro cultures by affinity chromatography and fast protein liquid chromatography. rabbit antibodies to ag2 were raised and characterized by crossed immunoelectrophoresis. ag2 appeared as a duplet with molecular masses of 136 and 120 kda when tested by immunoblotting. immunoprecipitation experiments on triton x-100 extracted antigens from synchronized cultures showed that the antigen w ... | 1991 | 2001282 |
| clinical and laboratory features of severe and complicated falciparum malaria the experience from gonder hospital. | over a period of 6 months in 1988, 104 patients with severe and complicated falciparum malaria were admitted to the gonder college hospital (gch), gonder, ethiopia; 85 male (81.7%) and 19 female (18.3%). the age ranged between 14 and 70 years with a mean age of 31 years. eighty-one patients (78.3%) had moved from a nonendemic to a malariaendemic area shortly before their illness. altered state of consciousness, hyperparasitaemia and severe anaemia were the most frequent complications found. fift ... | 1991 | 2001687 |