| missense mutations and evolutionary conserved amino acids at the human hypoxanthine phosphoribosyl-transferase locus. | molecular characterization of in vivo mutation at the human hypoxanthine phosphoribosyltransferase (hprt) locus has revealed a broad spectrum of mutation, both with regard to germ-line mutation in lesch-nyhan and gout patients, and somatic mutation in 6-thioguanine resistant t-lymphocytes from healthy individuals. the pattern of missense mutation shows a non-random distribution with a preferential location to codons for amino acids which are identical in human and the two parasites schistosoma m ... | 1992 | 1306134 |
| [malaria imported into turin: epidemiological observations (1980-1990)]. | | 1992 | 1306171 |
| [studies on the establishment of malarial animal model of short-term relapse. i. asynchronous growth of exoerythrocytic schizonts of plasmodium cynomolgi]. | a monkey was infected with sporozoites of plasmodium cynomolgi from vietnam. parasitemia was detected on the 8th day with a starting density of 17/100 white blood cells. 22 hours after that time, many ee schizonts appeared with an average density of 3.74 +/- 0.66 per mm3 hepatic tissue in liver biopsy specimens from the monkey. most of the ee schizonts were immature and grew at an uneven rate, having an average diameter of 34.22 +/- 7.28 microns but some of them even remained 15.75 +/- 2.47 micr ... | 1992 | 1307269 |
| [characterization of a surface antigen of plasmodium falciparum merozoite with monoclonal antibody]. | the monoclonal antibody (mcab) designated as c6 against erythrocytic stage of plasmodium falciparum fcc7801/hn showed significant growth inhibition of p. falciparum in vitro, having cross immunofluorescence reaction with p. falciparum fcc-1/hn, fcc7802/hn, fcc8703/js and p. berghei, p. cynomolgi. mcab c6 bound to the antigen distributed evenly over the entire surface of merozoites of p. falciparum, as demonstrated by immunoelectron microscopy. the mcab c6 also recognized a single protein of 71 k ... | 1992 | 1307271 |
| [sensitivity in vitro of plasmodium falciparum to chloroquine, pyronaridine, artesunate and piperaquine in south yunnan]. | the sensitivity of p. falciparum to chloroquine, pyronaridine, artesunate and piperaquine (cq, pd, at, pq) was assayed using in vitro microtechnique in south yunnan in 1990. the resistance rates were 98.7% (75/76), 27.6% (16/58), 13.8% (9/65) and 97.7% (43/44) respectively, and id50 were 125.0, 19.0, 4.7 and 243.3 nmol/l, respectively. the resistance rate against cq showed no change as compared to the rates against cq 5 and 9 years ago; but the id50 was lower. cq-resistant p. falciparum showed a ... | 1992 | 1307275 |
| [effect of sodium artesunate on plasmodium yoelii analysed by flow cytometry]. | the effect of sodium artesunate on plasmodium yoelii-infected mouse erythrocytes was analysed by flow cytometry. the results showed that malarial dna content in experimental group was obviously decreased 2-5 hours after the drug was administered, fluorescence distribution of malarial dna almost disappeared within 24 hours after the administration. thus we deem that sodium artesunate can inhibit the dna synthesis in p. yoelii. | 1992 | 1307277 |
| neurological manifestations of malaria. | the involvement of the nervous system in malaria is reviewed in this paper. cerebral malaria, the acute encephalopathy which complicates exclusively the infection by plasmodium falciparum commonly affects children and adolescents in hyperendemic areas. plugging of cerebral capillaries and venules by clumped, parasitized red cells causing sludging in the capillary circulation is one hypothesis to explain its pathogenesis. the other is a humoral hypothesis which proposes nonspecific, immune-mediat ... | 1992 | 1307475 |
| malarial placental infection and low birth weight babies. | two hundred and fifty six mothers and their newborns were subjected to clinical and haematological tests for the evidence of malaria. placentae of these were examined histopathologically for malarial parasites and malarial pigment. forty six placentae showed scanty malarial pigment ingested by monocytes. these appearances were associated with focal syncytial necrosis and proliferation of cytotrophoblastic cells. plasmodium falciparum was found in cord blood of six cases. the mean weight of newbo ... | 1992 | 1307763 |
| "antimalarial" medicinal plants and their impact on cell populations in various organs of mice. | we have investigated the effects of leaf and bark decoctions of ocimum gratissimum, azadirachta indica, morinda lucida and enantia chlorantha on (a) the course of plasmodium yoelii nigeriensis malaria (b) reticulocyte and haematocrit values and (c) nucleated cell numbers in the spleen, bone marrow, peritoneum, liver and peripheral blood of swiss albino mice. results obtained showed that normal mice infected with the parasite (10(4)/mouse) suffered fulminant parasitaemia which resulted in death, ... | 1992 | 1308080 |
| isolation and characterization of a plasmodium falciparum strain: comparative study with four described strains. | | 1992 | 1308546 |
| infection of anopheles darlingi fed on patients infected with plasmodium vivax before and during treatment with chloroquine plus primaquine in costa marques, rondönia, brazil. | five patients with asexual and sexual parasites of plasmodium vivax were treated orally with 600 mg chloroquine diphosphate (hour 0) followed with 300 mg at 8, 24 and 48 h later. primaquine phosphate, 15 mg, was administered concurrently at h 0 and at 24 h intervals for 14 days. anopheles darlingi were fed before the first dose (h -0.5) and 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48, 60 and 72 h later. mosquitoes were examined for oocysts on day 8 and for sporozoites on day 15 after infectio ... | 1992 | 1308564 |
| malaria seroepidemiology: comparison between indirect fluorescent antibody test and enzyme immunoassay using bloodspot eluates. | blood sampling on filter paper is a current practice in malaria seroepidemiological studies by indirect fluorescent antibody test (ifat). there is, however, scant comparative information about the use of bloodspot eluates for detection of malarial igg antibodies simultaneously by ifat and enzyme immunoassay (elisa). here we report data obtained by both serological methods done on 219 bloodspot eluate samples collected in a rural community in brazilian amazon basin (alto paraíso, ariquemes munici ... | 1992 | 1308565 |
| chemotherapy and immunity in opportunistic parasitic infections in aids. | parasitic diseases are endemic in parts of the tropics, but there is no convincing evidence that their prevalence or incidence is increasing due to the hiv epidemic. available scientific data on parasitic infections in patients with the acquired immunodeficiency syndrome (aids) suggests a predominance of pneumocystis carinii, toxoplasma gondii and cryptosporidium spp. for reasons which are unclear, parasitic infections such as plasmodium falciparum, strongyloides stercoralis and entamoeba histol ... | 1992 | 1308934 |
| a malaria invasion receptor, the 175-kilodalton erythrocyte binding antigen of plasmodium falciparum recognizes the terminal neu5ac(alpha 2-3)gal- sequences of glycophorin a. | plasmodium falciparum malaria parasites invade human erythrocytes by means of a parasite receptor for erythrocytes, the 175-kd erythrocyte binding antigen (eba-175). similar to invasion efficiency, binding requires n-acetylneuraminic acid (neu5ac) on human erythrocytes, specifically the glycophorins. eba-175 bound to erythrocytes with receptor-like specificity and was saturable. the specificity of eba-175 binding was studied to determine if its binding is influenced either by simple electrostati ... | 1992 | 1310320 |
| daphnetin: a novel antimalarial agent with in vitro and in vivo activity. | daphnetin is a dihydroxycoumarin that is being used in china for the treatment of coagulation disorders. it is also a chelator and an antioxidant. in vitro, daphnetin causes a 50% inhibition (ic50) of 3h-hypoxanthine incorporation by plasmodium falciparum at concentrations between 25 and 40 microm. several related compounds, such as scopoletin, 2, 3-dihydroxybenzoic acid and 3, 4-dihydroxybenzoic acid show no inhibitory activity. the antimalarial activity of daphnetin is inhibited by the additio ... | 1992 | 1311154 |
| macrophage activation during plasmodium chabaudi as infection in resistant c57bl/6 and susceptible a/j mice. | macrophage activation was examined in resistant c57bl/6 and susceptible a/j mice during the course of blood-stage infection with plasmodium chabaudi as. three parameters of macrophage activation (lipopolysaccharide [lps]- and malaria antigen-induced tumor necrosis factor [tnf] production in vitro, phorbol myristate acetate [pma]-induced production of oxygen metabolites in vitro, and ia antigen expression) were assessed during infection in populations of peritoneal and splenic macrophages recover ... | 1992 | 1311705 |
| site of action of the antimalarial hydroxynaphthoquinone, 2-[trans-4-(4'-chlorophenyl) cyclohexyl]-3-hydroxy-1,4-naphthoquinone (566c80). | the site of action of the antimalarial compound 2-[trans-4-(4'-chlorophenyl) cyclohexyl]-3-hydroxy-1,4-naphthoquinone (566c80), would appear to be the mitochondrial respiratory chain. studies reported herein have demonstrated 566c80 to be a potent and selective mitochondrial inhibitor with mitochondria isolated from plasmodium falciparum and p. yoelii. selective assay of individual respiratory chain complexes has shown the primary site of action of 566c80 to be the cytochrome bc1 complex (comple ... | 1992 | 1314606 |
| phosphorylation by actin kinase of the pointed end domain on the actin molecule. | fragmin from plasmodium of physarum polycephalum binds g-actin and severs f-actin in the presence of ca2+ over 10(-6) m. the fragmin-actin complex consisting of fragmin and g-actin nucleates actin polymerization and caps the barbed (fast growing) end of f-actin, regardless of the concentrations of ca2+, and the actin filaments are shortened. actin kinase purified from plasmodium abolishes the nucleation and capping activities of the complex by phosphorylating actin of the fragmin-actin complex ( ... | 1992 | 1315751 |
| status of oxidative stress and antioxidant defences during plasmodium knowlesi infection and chloroquine treatment in macaca mulatta. | plasmodium knowlesi (a simian malarial parasite) infection resulted in elevation of hepatic oxidative stress in monkeys. further, the antioxidant defence system of the host was also noticeably affected. the infected monkeys showed a marked increase in the levels of superoxide (o2-), lipid peroxidation (lpo), glutathione (gsh) and xanthine oxidase (xo), and decreased levels of superoxide dismutase (sod) and catalase. oral administration of chloroquine (20 mg kg body wt-1 for 3 days) to infected m ... | 1992 | 1316884 |
| plasmodium falciparum and plasmodium chabaudi: characterization of glycosylphosphatidylinositol-degrading activities. | merozoites of malaria parasites have a membrane-bound serine protease whose solubilization and subsequent activity depend on a parasite-derived glycosylphosphatidylinositol-phospholipase c (gpi-plc). the gpi-degrading activities from both plasmodium falciparum and plasmodium chabaudi have been characterized and partially purified by phenylboronate chromatography. they are membrane-bound, developmentally regulated, calcium-independent enzymes and as such they resemble gpi-plc of trypanosoma bruce ... | 1992 | 1317298 |
| localization of a 230-kd parasitophorous vacuole membrane antigen of plasmodium berghei exoerythrocytic schizonts (lsa-2) by immunoelectron and confocal laser scanning microscopy. | using antiserum to a 230-kd parasitophorous vacuole membrane (pvm) antigen of plasmodium berghei exoerythrocytic schizonts as a specific probe for the pvm, we studied the three-dimensional structure of this membrane within infected host cells by immunoelectron microscopy and confocal laser scanning microscopy at 3, 4, and 50 hr after sporozoite invasion. fluorescent label was not detected at 3 hr, but was associated with the cytoplasm of 24-hr-old exoerythrocytic parasites. specific labeling of ... | 1992 | 1318005 |
| the 6-kb element of plasmodium falciparum encodes mitochondrial cytochrome genes. | | 1992 | 1320735 |
| subset heterogeneity among gamma delta t cells found in peripheral blood during plasmodium falciparum malaria. | | 1992 | 1323528 |
| recombinant pseudorabies virus carrying a plasmodium gene: herpesvirus as a new live viral vector for inducing t- and b-cell immunity. | in balb/c mice, the sterile protective immunity induced by immunization with radiation-attenuated plasmodium yoelii sporozoites is eliminated by in vivo depletion of cd8+ t lymphocytes, suggesting that cytotoxic t lymphocytes (ctl) against malaria antigens expressed on infected hepatocytes are required for mediating this protective immunity. to produce a vaccine that would induce ctl against the p. yoelii circumsporozoite protein (cs), we constructed an attenuated pseudorabies virus (prv) contai ... | 1992 | 1323900 |
| activity of azithromycin (cp-62,993) and erythromycin against chloroquine-sensitive and chloroquine-resistant strains of plasmodium falciparum in vitro. | several antibiotics, including the macrolide erythromycin and the azalides azithromycin (cp-62,993) and cp-63,956, that inhibit protein synthesis on 70s ribosomes demonstrated antimalarial effects in vitro against two strains of plasmodium falciparum, one sensitive to chloroquine and the other resistant. in 48-hr incubations, erythromycin was 10-fold less potent than the azalides against the chloroquine-resistant strain. erythromycin and the azalides were essentially equipotent against the chlor ... | 1992 | 1326232 |
| the basolateral domain of the hepatocyte plasma membrane bears receptors for the circumsporozoite protein of plasmodium falciparum sporozoites. | minutes after injection into the circulation, malaria sporozoites enter hepatocytes. the speed and specificity of the invasion process suggest that it is receptor mediated. we show here that recombinant plasmodium falciparum circumsporozoite protein (cs) binds specifically to regions of the plasma membrane of hepatocytes exposed to circulating blood in the disse space. no binding has been detected in other organs, or even in other regions of the hepatocyte membrane. the interaction of cs with he ... | 1992 | 1326407 |
| [involvement of cellular immunity in pathology. neuromalaria]. | murin cerebral malaria (mcm) with plasmodium berghei anka and the cba/ca mice is the result of an immunopathological process. an overproduction of tnf is implicated in its pathogenesis. recent datas concerning tnf production during the course of plasmodium vinckei vinckei infection, and analysis of relationships between mcm and experimental allergic encephalomyelitis (eae) raise the hypothesis of the involvement of an auto-immune process in the murin disease. the role of cellular immunity in hum ... | 1992 | 1327351 |
| [pathophysiology of malaria. the current issue]. | patho-physiology of malaria is often presented with very old, rudimentary and not scientifically proved explanations. in fact, the mechanisms involved in malaria and mainly in cerebral malaria are very complex and, until now, partly unknown. four hypotheses (sludging, modifications or blood-brain barrier permeability, mechanical or immunological phenomena) have to be considered. several cytokines and mainly tnf seem to play the major role but other parameters are also essential in relation with ... | 1992 | 1327352 |
| incorporation of free fatty acids can explain alterations in the molecular species composition of phosphatidylcholine and phosphatidylethanolamine in human erythrocytes as induced by plasmodium falciparum. | phosphatidylcholine (pc) and phosphatidylethanolamine (pe) species composition of human erythrocytes changes upon intraerythrocytic development of plasmodium falciparum. though the activity of the phosphotransferases which catalyze the last step of the kennedy pathway for the synthesis of pc and pe is dependent of the species on diacylglycerol, it appeared that this cannot, by itself, explain the alterations found in pc and pe molecular species composition. when the incorporation of radiolabeled ... | 1992 | 1327542 |
| gamete development in plasmodium berghei regulated by ionic exchange mechanisms. | ionic regulation in the induction of exflagellation of plasmodium berghei was investigated by culturing the parasites in various isotonic media. of the salts tested, nahco3 exhibited the highest activity in inducing exflagellation, whereas khco3 showed no activity. in the absence of hco3-, media containing monovalent cation (na+, k+, cs+, rd+, choline+, lysine+, arginine+) and cl- also induced exflagellation, but their activities were lower than that of nahco3. anions of br- or no3- could be sub ... | 1992 | 1329079 |
| host resistance assays as predictive models in styrene immunomodulation. | three infection models namely an oncogenic virus encephalomyocarditis (emcv), a rodent strain of malaria, plasmodium berghei, and a rodent hookworm parasite, nippostrongylus brasiliensis, were used to confirm the in vivo immunotoxic potential of styrene reported in our previous communication. the altered host resistance to these challenge infections was evaluated in rodents pre-treated with 0, 0.02, 0.03 or 0.05 x ld50 dose of styrene (5 days/week) for 4 weeks. significantly increased mortality ... | 1992 | 1330943 |
| [the relation between changes in the intestinal microflora of mosquito larvae under the action of phytobacteriomycin and female susceptibility to the causative agent of malaria]. | a relationship was found between pseudomonas suppression by phytobacteriomycin (pbm) in the mosquito larval gut and the mosquito vectorial capacity. the suppression of pseudomonas bacteria in larvae caused a decrease in the vectorial capacity of emerged imagines. the results of the in vivo tests were verified in vitro with the culture of bacteria isolated from mosquito larva in liquid medium with ph 8.4 which is equal to intestinal ph of ae. aegypti larva inside the peritrophic membrane. the lab ... | 1992 | 1331732 |
| [an evaluation of the effect of phytobacteriomycin on the malarial parasite in the mosquito]. | | 1992 | 1331733 |
| [treatment of malaria in children in france]. | currently, most of the subjects presenting with plasmodium falciparum malaria in france come from areas where chloroquine resistance has already been reported. treatment of uncomplicated malaria should consist of oral administration of either quinine or mefloquine or halofantrine. in children, halofantrine seems to be the treatment of choice at any age. the prognosis of cerebral malaria depends on how fast the diagnosis is made and the treatment is undertaken. the detection of clinical and biolo ... | 1992 | 1331951 |
| correlation between destruction of malarial parasites by polymorphonuclear leucocytes and oxidative stress. | the role of reactive oxygen species (ros) generated by polymorphonuclear leucocytes (pmns) in the host response against malaria was investigated. non-activated human pmns were added to cultures of p. falciparum in microtitre cells. parasite viability was evaluated by the incorporation of radioactive hypoxanthine. using pmn/rbc = 1/150 (starting parasitemia was 1%) the incorporation on the second day in culture was only 61% of the control cultures. an effect could be observed already after two ho ... | 1992 | 1335429 |
| population genetics of microbial organisms. | population data suggest that many parasitic protozoa (e.g. trypanosoma, leishmania, entamoeba and giardia) reproduce clonally, but this hypothesis has been highly controversial for plasmodium falciparum. although reproduction is predominantly clonal in the enteric bacteria escherichia coli and salmonella, the level of recombination affecting short (< 1 kb) regions of the chromosome is sufficient such that many genes are obviously mosaics of different ancestries. transposable insertion sequences ... | 1992 | 1335810 |
| cloning and characterization of a novel multicopy, repetitive sequence of plasmodium falciparum, rep51. | | 1992 | 1339406 |
| [in vivo chemosensitivity of plasmodium falciparum to chloroquine in burkina faso: development of resistance 1988-1990]. | a study of plasmodium falciparum sensitivity to chloroquine was carried out in 1988 and 1990 in 5 localities, representatives of different climatic areas of burkina faso. the 7-day in vivo standard test performed in 1988 showed a total clearance failure of 25%. no significant difference with 1990 data was found, except for an increase of the resistance in the area of fada n'gourma, close to the border with benin, niger and togo. | 1992 | 1339966 |
| malaria transmission in a central area of futa djalon (guinea): results of a parasitological survey during the 1989 rainy season. | a malaria survey based on household surveys and dispensary visits without notice was carried out during the rainy season of 1989 in three selected areas of central futa djalon (republic of guinea). preliminary entomological evidence showed that anopheles gambiae was the main vector in the area with a cs positive rate of 7.6% and a human blood index of 78% in august 1989. indoor resting densities were highest in the rural village, lowest in labé and intermediate in the town of timbi madina (media ... | 1992 | 1339967 |
| [extension of the area of aedes albopictus in italy. 1st report of the species in central italy]. | a new infestation by aedes albopictus was discovered in civitavecchia, central italy, in october 1992. this follows previous records of the species in north italy, where the first infestation was observed in 1990 in the city of genoa. the present finding clearly indicates the capacity of aedes albopictus to spread all over italy and to become a permanent pest in southern europe. in spite of the expected embryonic diapause in october, larval breeding was observed in a fifteen-liter glass jar with ... | 1992 | 1339968 |
| malaria transmission in the lagoon area of cotonou, benin. | a study of the prevalence and intensity of malaria transmission in the lagunar area of benin was carried out by means of repeated cross-sectional surveys of the child population. six areas were selected: two urban areas of cotonou, three lagunar villages and one savanna village. slide positive rates and prevalence of antibodies to p. falciparum sporozoites were examined in june-july 1989 (long rainy season), october-november 1989 (short rainy season) and march-april 1990 (short dry season). para ... | 1992 | 1339969 |
| [a spectrophotometric study of the interaction of neutral red with lysates of erythrocytes infected with plasmodium berghei]. | | 1992 | 1340261 |
| p. falciparum strain resistance to drugs. new drug trials. | | 1992 | 1340625 |
| control of malaria vectors in the amazon region. i. implications of insecticide resistance. | | 1992 | 1340626 |
| intervention possibilities on the biologic cycle of malaria towards endemism control. | | 1992 | 1340628 |
| ethics on malaria seroepidemiology. | | 1992 | 1340631 |
| malaria vaccines: scientific and ethical issues. | | 1992 | 1340632 |
| clinical picture of severe malaria. | | 1992 | 1340633 |
| chemoprophylaxis against malaria in papua new guinea: a trial of amodiaquine and a combination of dapsone and pyrimethamine. | a placebo-controlled chemoprophylaxis trial was carried out in 1980 in 318 semi-immune school children in the madang area of papua new guinea, where there was a high prevalence of strains of plasmodium falciparum resistant to 4-aminoquinolines. since prophylaxis with amodiaquine at 5 mg/kg weekly had failed, amodiaquine at a dose of 10mg/kg weekly and maloprim (half a tablet or one tablet depending on body weight, which gave ranges of dapsone of 1.7-3.3mg/kg and pyrimethamine 0.2-0.4 mg/kg) week ... | 1992 | 1341089 |
| the malaria vaccine epidemiology and evaluation project of papua new guinea: rationale and baseline studies. | the range of possible malaria vaccines, against different species of plasmodium and various stages in the life cycle of the parasite in both human host and mosquito vector, is reviewed. the importance, in a malaria-endemic area, of protection by a malaria vaccine against disease rather than infection is emphasized, and the ways by which disease prevention may be achieved are discussed. mechanisms of production and presentation of vaccines are considered, including the importance of appropriate a ... | 1992 | 1341090 |
| prenatal immune hypersensitization to malaria: plasmodium falciparum-specific ige antibody in paired maternal and cord sera from papua new guinea. | in a study of malaria and pregnancy in east sepik province of papua new guinea 45 maternal and cord serum pairs were tested for plasmodium falciparum-specific ige antibody. there were 17 positive sera: 6 cases of maternal serum alone, 5 cases of cord serum alone and 3 pairs of maternal and cord sera. ige antibody positivity rates in the mothers increased with parity, whereas placental parasitaemia rates decreased. cord serum positivity was not affected by parity. immunoblots of the sera revealed ... | 1992 | 1341092 |
| a method for screening drugs against the liver stages of malaria using plasmodium gallinaceum and aedes mosquitos. | 1. the radical cure of human malaria caused by plasmodium vivax requires two drugs, i.e., a blood schizontocide such as chloroquine to clear the circulating parasites, and primaquine aimed at the liver stages (hyponozoites) responsible for the late relapses of this parasite. primaquine is unique as a radical curative drug but is highly toxic. the only useful model currently available for screening drugs to replace primaquine is plasmodium cynomolgi-induced malaria in rhesus monkeys. because of t ... | 1992 | 1341921 |
| a randomized clinical trial with high dose of chloroquine for treatment of plasmodium falciparum malaria in brazil. | this clinical trial compared parasitological efficacy, levels of in vivo resistance and side effects of oral chloroquine 25 mg/kg and 50 mg/kg in 3 days treatment in plasmodium falciparum malaria with an extended followed-up of 30 days. the study enrolled 58 patients in the 25 mg/kg group and 66 in the 50 mg/kg group. all eligible subjects were over 14 years of age and came from amazon basin and central brazil during the period of august 1989 to april 1991. the cure rate in the 50 mg/kg group wa ... | 1992 | 1342112 |
| [characterization and antigenic relationship of 3 new bunyaviruses in the group anopheles a (bunyaviridae) of arboviruses]. | the isolation and characterization of three new viruses obtained from the tucuruí hydroelectric dam region is reported. these three agents belong to the anopheles a serogroup, genus bunyavirus, bunyaviridae. the tucuruí (tuc), caraipé (cpe) and arumateua (art) viruses have close relationships with each other and with trombetas (tbt) virus, an anopheles a virus previously isolated in the amazon region of brazil. these viruses form the "trombetas complex". tuc, cpe and art viruses were obtained fr ... | 1992 | 1342498 |
| modern immunological approaches to assess malaria transmission and immunity and to diagnose plasmodial infection. | the present paper reviews our recent data concerning the use of immunological methods employing monoclonal antibodies and synthetic peptides to study malaria transmission and immunity and to diagnose plasmodial infection. as concerns malaria transmission, we studied the main vectors of human malaria and the plasmodial species transmitted in endemic areas of rondônia state, brazil. the natural infection of anopheline was evaluated by immunoradiometric assay (irma) using monoclonal antibodies to a ... | 1992 | 1342707 |
| virulence and the immune response in malaria. | many factors determine the virulence of a malaria infection. these include host innate resistance mechanisms and, with plasmodium falciparum, the ability to cytoadhere to endothelial cells, form rosettes, and induce release of cytokines. the effect on virulence of acquired immune responses can be determined by class i and class ii mhc-antigens; levels of immunological responsiveness may be determined too in other ways. the structure of parasite surface antigens and their great diversity modulate ... | 1992 | 1342711 |
| mechanisms of immune protection in the asexual blood stage infection by plasmodium falciparum: analysis by in vitro and ex-vivo assays. | mechanisms of immune protection against the asexual blood stage infection by plasmodium falciparum are reviewed. recent studies of two independent lines of research developed at the institut pasteur, in humans and primate infections clearly indicate an obligatory interaction of antibodies and effector cells to express the anti-parasitic effect. | 1992 | 1342712 |
| immunopathology of malaria: role of cytokine production and adhesion molecules. | | 1992 | 1342724 |
| use of glass beads and cf 11 cellulose for removal of leukocytes from malaria-infected human blood in field settings. | passage of malaria-infected blood through a two-layered column composed of acid-washed glass beads and cf 11 cellulose removes white cells from parasitized blood. however, because use of glass beads and cf 11 cellulose requires filtration of infected blood separately through these two resins and the addition of adp, the procedure is time-consuming and may be inappropriate for use in the field, especially when large numbers of blood samples are to be treated. our modification of this process yiel ... | 1992 | 1343674 |
| non-phenolic method of dna purification from bacteria, blood samples and other biological sources for restriction enzyme assays and the polymerase chain reaction. | | 1992 | 1343675 |
| simian malaria in brazil. | in brazil simian malaria is widely spread, being frequent in the amazon region (10% of primates infected) and even more in the forested coastal mountains of the southeastern and southern regions (35% and 18% infected, respectively), but absent in the semi-arid northeast. only two species of plasmodia have been found: the quartan-like plasmodium brasilianum and the tertian-like p. simium, but the possible presence of other species is not excluded. p. brasilianum is found in all enzootic foci, but ... | 1992 | 1343676 |
| household-based malaria control in a highly endemic area of africa (tanzania): determinants of transmission and disease and indicators for monitoring--kilombero malaria project. | the kilombero malaria project (kmp) attempts to define operationally useful indicators of levels of transmission and disease and health system relevant monitoring indicators to evaluate the impact of disease control at the community or health facility level. the kmp is a longitudinal community based study (n = 1024) in rural southern tanzania, investigating risk factors for malarial morbidity and developing household based malaria control strategies. biweekly morbidity and bimonthly serological, ... | 1992 | 1343680 |
| on the current existence of a coccidial line of development in the malaria parasites: a theory. | most opinion favors the origin of the malaria parasites from a coccidial ancestor. it is assumed that whatever the process through which the coccidia differentiated into a plasmodium this phenomenon very probably occurred millions of year ago, and during that differentiation process the original coccidia vanished. therefore it has never been repeated. at the light of some experiments the existence, at the present time, of a coccidial cycle of development in the malaria parasites, is proposed. th ... | 1992 | 1343685 |
| immunogenicity and antigenicity of the n-term repeat amino acid sequence of the plasmodium falciparum p126 antigen. | the p126 protein, a parasitophorus vacuole antigen of plasmodium falciparum has been shown to induce protective immunity in saimiri and aotus monkeys. in the present work we investigated its immunogenicity. our results suggest that the n-term of p126 is poorly immunogenic and the antibody response against the p126 could be under a mhc restricted control in c57bl/6(h-2b) mice, which could be problematic in terms of a use of the p126 in a vaccine program. however, we observed that a synthetic pept ... | 1992 | 1343686 |
| induction of plasmodium falciparum transmission-blocking antibodies by recombinant pfs25. | | 1992 | 1343687 |
| a recombinant hybrid protein as antigen for an anti-blood stage malaria vaccine: a study on the conservation of a protective component. | recently we have shown that two hybrid proteins expressed in escherichia coli confer protective immunity to aotus monkeys against an experimental plasmodium falciparum infection (knapp et al., 1992). both hybrid proteins carry a sequence containing amino acids 631 to 764 of the serine stretch protein serp (knapp et al., 1989b). we have studied the diversity of this serp region in field isolates of p. falciparum. genomic dna was extracted from the blood of six donors from different endemic areas ... | 1992 | 1343688 |
| development of an immunoenzymatic assay using a monoclonal antibody against a 50-kda catabolite from the p126 plasmodium falciparum protein to the diagnosis of malaria infection. | the who criterion of defering any donation of blood by a confirmed case of malaria for three years after cessation of therapy can not be applied in areas where malaria is endemic. for this reason we developed an immunoenzymatic assay for the detection of plasmodial antigens for blood screening in malarial endemic areas. so, we tested sera from 191 individuals. among patients with active disease 100% of the cases of plasmodium falciparum or mixed infections and 91.7% of those with p. vivax were p ... | 1992 | 1343689 |
| antibodies in falciparum malaria: what matters most, quantity or quality? | in view of the recent demonstration that antibodies that are protective against plasmodium falciparum malaria may act in collaboration with blood monocytes, we have investigated the isotype content of sera from individuals with defined clinical states of resistance or susceptibility to malaria. profound differences in the distribution of each ig subclass and particularly in the ratio of cytophilic versus noncytophilic antibodies were found. in protected subjects, two cytophilic isotypes, igg1 an ... | 1992 | 1343695 |
| basic biochemical investigations as rationale for the design of original antimalarial drugs. an example of phospholipid metabolism. | the future of antimalarial chemotherapy is particularly alarming in view of the spread of parasite cross-resistances to drugs that are not even structurally related. only the availability of new pharmacological models will make it possible to select molecules with novel mechanisms of action, thus delaying resistance and allowing the development of new chemotherapeutic strategies. we reached this objective in mice. our approach is hunged on fundamental and applied research begun in 1980 to invest ... | 1992 | 1343697 |
| in vitro mutagenesis defines drug targets in aldolase of plasmodium falciparum. | | 1992 | 1343698 |
| mefloquine resistant malaria in cameroon and correlation with resistance to quinine. | based on the results of in vitro sensitivity of plasmodium falciparum to chloroquine, quinine and mefloquine, and evaluation of drug consumption conducted in 1987-1988 in four areas in the north and south-west of cameroon, two opposite situations were encountered in this country. in northern cameroon where mefloquine resistance is prevalent a close correlation was found between the responses of p. falciparum to mefloquine and to quinine, but not between mefloquine and chloroquine. in the south, ... | 1992 | 1343701 |
| a study on the pathogenesis of human cerebral malaria and cerebral babesiosis. | cerebral complications are important, but poorly understood pathological features of infections caused by some species of plasmodium and babesia. patients dying from p. falciparum were classified as cerebral or non-cerebral cases according to the cerebral malaria coma scale. light microscopy revealed that cerebral microvessels of cerebral malaria patients were filled with a mixture of parasitized and unparasitized erythrocytes, with 94% of the vessels showing parasitized red blood cell (prbc) se ... | 1992 | 1343706 |
| optimization and inhibition of the adherent ability of plasmodium falciparum-infected erythrocytes. | the vast majority of the 1-2 million malaria associated deaths that occur each year are due to anemia and cerebral malaria (the attachment of erythrocytes containing mature forms of plasmodium falciparum to the endothelial cells that line the vascular beds of the brain). a "model system" for the study of cerebral malaria employs amelanotic melanoma cells as the "target" cells in an in vitro cytoadherence assay. using this model system we determined that the optimum ph for adherence is 6.6 to 6.8 ... | 1992 | 1343707 |
| variation in the cytoadherence characteristics of malaria parasites: is this a true virulence factor? | the sequestration of plasmodium falciparum-infected erythrocytes to the endothelial cells of brain capillaries is believed to represent one of the determining factors in the pathogenesis of cerebral malaria. in vitro studies of cytoadherence provide an experimental approach to understand the mechanism of sequestration and the respective roles played by parasite and host components in this interaction. this paper critically reviews current studies on cytoadherence, with particular emphasis on the ... | 1992 | 1343708 |
| cytokines and dysregulation of the immune response in human malaria. | the dysregulation of the immune response by malaria parasite has been considered as a possible constraint to the effectiveness of malaria vaccination. in spite of the important role interleukin-1 (il-1) plays on the immunoregulation, and its ability to mimic various features of clinical malaria, reports on il-1 in malaria are lacking. we found that only 2 out of 35 subjects with acute malaria showed increased levels of serum il-1 alpha by enzyme immunoassay. to assess whether il-1 could interfer ... | 1992 | 1343709 |
| epidemiological distribution of plasmodium falciparum drug resistance in brazil and its relevance to the treatment and control of malaria. | with the use of a simple formulary, filled by health agents was established a monitoring programme for responses of p. falciparum to the antimalarial drugs. this monitoring programme is emphasized for the knowledge of the epidemiology of the drug resistance and the control of malaria falciparum in amazon basin where occurs more than 95% of brazilian malaria cases every year. it was demonstrated that still now 4-aminoquinolines have a great importance for the mortality control in areas where just ... | 1992 | 1343711 |
| efficacy of insecticide impregnated bed-nets to control malaria in a rural forested area in southern cameroon. | due to current spreading of chemoresistant strains of plasmodium falciparum malaria control must incorporate vector control programmes. due to well known constraints house sprayings cannot be performed as before. personal protection can be developed and a large scale use of insecticide treated bed-nets appeared to be very useful to reduce man-vector contact in asia, south america and west and east africa. no trial has been done in forest central africa where transmission is permanent. we perform ... | 1992 | 1343714 |
| a malaria merozoite surface protein (msp1)-structure, processing and function. | merozoite surface protein-1 (msp-1, also referred to as p195, pmmsa or msa 1) is one of the most studied of all malaria proteins. the protein is found in all malaria species investigated and structural studies on the gene indicate that parts of the molecule are well-conserved. studies on plasmodium falciparum have shown that the protein is in a processed form on the merozoite surface, a result of proteolytic cleavage of the large precursor molecule. recent studies have identified some of these c ... | 1992 | 1343716 |
| ecology of malaria vectors in the americas and future direction. | the resurgence of malaria in the americas has renewed interest in anopheles biology. anopheles darlingi, an. albimanus, an. nuneztovai and an. aquasalis are reconfirmed as major malaria vectors and other species are playing important roles in regional malaria transmission. adult biting activity and larval ecology are discussed in detail. seasonal abundance and daily biting activity of anophelines vary considerably among species and geographically for the same species. anopheles albimanus has the ... | 1992 | 1343717 |
| transmission factors in malaria epidemiology and control in africa. | genetic and environmental components of factors contributing in malaria transmission are reviewed. particular attention is given to density dependent regulation of vector populations in relation to the survival rate of anophelines. the expectation of vector control activities are different according to the epidemiological characteristics of malaria, mainly its stability. in areas with perennial and high transmission (stable malaria) vector control could reduce malaria related morbidity and morta ... | 1992 | 1343718 |
| vector incrimination and effects of antimalarial drugs on malaria transmission and control in the amazon basin of brazil. | world ecosystems differ significantly and a multidisciplinary malaria control approach must be adjusted to meet these requirements. these include a comprehensive understanding of the malaria vectors, their behavior, seasonal distribution and abundance, susceptibility to insecticides (physiological and behavioral), methods to reduce the numbers of human gametocyte carriers through effective health care systems and antimalarial drug treatment, urban malaria transmission versus rural or forest mala ... | 1992 | 1343719 |
| mechanisms of protective immunity against asexual blood stages of plasmodium falciparum in the experimental host saimiri. | in the saimiri monkey, an experimental host for human malaria, acquired protection against plasmodium falciparum blood stages depends on the igg antibody populations developed. in vivo protective anti-falciparum activity of igg antibodies is correlated with the in vitro opsonizing activity promoting phagocytosis of parasitized red blood cells. in contrast, non protective antibodies inhibit this mechanism by competing at the target level. a similar phenomenon can be observed in human infection. a ... | 1992 | 1343720 |
| protection of aotus monkeys after immunization with recombinant antigens of plasmodium falciparum. | the genus aotus spp. (owl monkey) is one of the who recommended experimental models for plasmodium falciparum blood stage infection, especially relevant for vaccination studies with asexual blood stage antigens of this parasite. for several immunization trials with purified recombinant merozoite/schizont antigens, the susceptible aotus karyotypes ii, iii, iv and vi were immunized with escherichia coli derived fusion proteins containing partial sequences of the proteins msai (merozoite surface an ... | 1992 | 1343721 |
| efficiency of human plasmodium falciparum malaria vaccine candidates in aotus lemurinus monkeys. | the protective efficacy of several recombinant and a synthetic plasmodium falciparum protein was assessed in aotus monkeys. the rp41 aldolase, the 190l fragment of the msa-1 protein and fusion 190l-cs. t3 protein containing the cs.t3 helper "universal" epitope were emulsified in freund's adjuvants and injected 3 times in groups of 4-5 monkeys each one. the synthetic polymer spf (66)30 also emulsified in freund's adjuvants was injected 6 times. control groups for both experiments were immunized w ... | 1992 | 1343722 |
| study of humoral immune response in mammals immunized with plasmodium falciparum antigenic preparations. | six plasmodium falciparum protein fractions, isolated under reducing conditions, were used to immunize mice, rabbits and the squirrel monkey saimiri sciureus. five or seven subcutaneous injections of each antigenic preparation, in conjunction with freund's complete or incomplete adjuvants, were administered. this led to the development of specific antibodies detected by ifat, elisa or immunoblotting which inhibited merozoite reinvasion in in vitro p. falciparum cultures. this activity seems to b ... | 1992 | 1343723 |
| impaired renal function in owl monkeys (aotus nancymai) infected with plasmodium falciparum. | impaired renal function was observed in sixteen aotus nancymai 25 and 3 months following infection with the uganda palo alto strain of plasmodium falciparum. decrease were noted in the clearance of endogenous creatinine, creatinine excretion, and urine volume while increases were observed in serum urea nitrogen, urine protein, urine potassium, fractional excretion of phosphorus and potassium, and activities of urinary enzymes. the results were suggestive of glomerulonephropathy and chronic renal ... | 1992 | 1343724 |
| plasmodium coatneyi-infected rhesus monkeys: a primate model for human cerebral malaria. | although several animal models for human cerebral malaria have been proposed in the past, none have shown pathological findings that are similar to those seen in humans. in order to develop an animal model for human cerebral malaria, we studied the pathology of brains of plasmodium coatneyi (primate malaria parasite)-infected rhesus monkeys. our study demonstrated parasitized erythrocyte (prbc) sequestration and cytoadherence of knobs on prbc to endothelial cells in cerebral microvessels of thes ... | 1992 | 1343725 |
| the role of cytokines in plasmodium vivax malaria. | the cytokine tumor necrosis factor and other as yet unidentified factor(s) which together mediate the killing of intraerythrocytic malaria parasites are transiently elevated in sera during paroxysms in human plasmodium vivax infections in non-immunes. these factors which included tnf and parasite killing factor(s) are associated with the clinical disease in malaria to the extent that their transient presence in infection sera coincided with paroxysms, the the most pronounced clinical disturbance ... | 1992 | 1343726 |
| molecular approaches to malaria and babesiosis diagnosis. | the development of additional methods for detecting and identifying babesia and plasmodium infections may be useful in disease monitoring, management and control efforts. the preliminary evaluate synthetic peptide-based serodiagnosis, a hydrophilic sequence (ddesefdkek) was selected from the published babr gene of b. bovis. immunization of rabbits and cattle with the hemocyanin-conjugated peptide elicited antibody responses that specifically detected both p. falciparum and b. bovis antigens by i ... | 1992 | 1343727 |
| new approaches in in vitro cultures of plasmodium falciparum and babesia divergens by using serum-free medium based on human high density lipoproteins. | | 1992 | 1343728 |
| human igg responses against the n-terminal region of the merozoite surface protein 1 of plasmodium vivax. | the complete primary structure of the gene encoding the merozoite surface protein 1 of plasmodium vivax (pvmsp-1) revealed the existence of interspecies conserved regions among the analogous proteins of other plasmodia species. here, three dna recombinant clones expressing 50, 200 and 500 amino acids from the n-terminal region of the pvmsp-1 protein were used on elisa and protein immunoblotting assays to look at the igg antibody responses of malaria patients from the brazilian amazon region of r ... | 1992 | 1343729 |
| a chromosome 9 deletion in plasmodium falciparum results in loss of cytoadherence. | many lines of plasmodium falciparum undergo a deletion of the right end of chromosome 9 during in vitro culture accompanied by loss of cytoadherence and gametocytogenesis. selection of cytoadherent cells from a mixed population co-selects for those with an undeleted chromosome 9 and the selected cells produce gametocytes. the deletion also results in loss of expression of pfemp1, the putative cytoadherence ligand, suggesting that pfemp1 or a regulatory gene controlling pfemp1 expression and game ... | 1992 | 1343730 |
| characterization of a plasmodium falciparium mutant that has deleted the majority of the gametocyte-specific pf11-1 locus. | we identified a gametocyte-specific protein of plasmodium falciparum called pf11-1 and provide experimental evidence that this molecule is involved in the emergence of gametes of the infected erythrocyte (gametogenesis). a mutant parasite clone, which has deleted over 90% of the pf11-1 gene locus, was an important control to establish the gametocyte-specific expression of the pf11-1. molecular analysis of the pf11-1 deletion indicates that it is presumably due to a chromosome breakage with subse ... | 1992 | 1343731 |
| deletion, insertion and translocation of dna sequences contribute to chromosome size polymorphism in plasmodium berghei. | extensive chromosome size polymorphism arises in plasmodium berghei during in vivo mitotic multiplication. size differences between homologous chromosomes mainly involve rearrangements in the subtelomeric regions while internal chromosomal regions are more conserved. size differences are almost exclusively due to differences in the copy number of a 2.3 kb subtelomeric repeat unit. not only deletion of 2.3 kb repeats occurs, but addition of new copies of this repeat sometimes results in the forma ... | 1992 | 1343732 |
| interrelationship between schistosomiasis and concomitant diseases. | the biological literature contains many examples of mutual influences between different species of parasites, especially with respect to concomitant helminth infections. several situations are known in which the association of infection by schistosoma mansoni with other pathogens in the same host results in a type of disease which differs from the simple summation of the individual effects of each infection. the present study concerns concomitant infections involving s. mansoni and enterobacteri ... | 1992 | 1343911 |
| importance of mean parasite clearance time and recrudescence time and their role in gradation of plasmodium falciparum resistance. | the present paper describes the relationship of mean parasite clearance time (mpct) and mean parasite recrudescence time (mprt) in the epidemiology of plasmodium falciparum. the role of mpct in grading the resistance of an area has been discussed. further, mprt revealed a positive correlationship with the percentage of ri resistant cases, and showed an increase with age. the ratio of mprt/mpct is an indicator of stability status of the resistance. | 1992 | 1344170 |
| malarial placental infection and low birth weight babies. | two-hundred fifty-six mothers and their newborns were subjected to clinical and haematological tests for the evidence of malaria. placentae of these were examined histopathologically for malarial parasites and malarial pigment. forty six placentae showed scanty malarial pigment ingested by monocytes. these appearances were associated with focal syncytial necrosis and proliferation of cytotrophoblastic cells. plasmodium falciparum was found in cord blood of six cases. the mean weight of newborns ... | 1992 | 1344172 |
| evaluation of indirect immunofluorescent antibody test for detection of igm specific antibodies in malaria. | indirect immunofluorescent antibody test using plasmodium falciparum antigen from in vitro culture was evaluated for detecting igm antibodies in order to determine the feasibility of its application in serodiagnosis of malaria. test was compared with the already adapted igg-iif test using the same antigen. it was found that none of the healthy controls and slide negative fever cases had malaria igm antibodies whereas 8 per cent of healthy controls and 49.01 per cent of the slide negative fever c ... | 1992 | 1344176 |
| lipid transport in plasmodium. | during intraerythrocytic development, the human malaria parasite plasmodium falciparum actively internalizes phospholipids from its erythrocyte membrane and the extracellular medium. the import of exogenous lipids is not due to endocytosis, but to energy-dependent, transbilayer movement of phospholipids induced by the parasite in the erythrocyte surface. novel tubular membranes that appear to emerge from the vacuole of the parasite and extend into the erythrocyte cytoplasm are labeled by exogeno ... | 1992 | 1344664 |
| [malaria and sickle-cell anemia. a correlation of the clinical and epidemiological aspects]. | a study was carried out on susceptibility of sicklemia patients to plasmodium falciparum (pf) malaria in 151 hemoglobin s carriers (homozygous and heterozygous), assisted at the cotonú hospital, benin, for 1 year. these diseased did not have any serious malaria complications. the results were compared to a control group without sickle-cell anemia who had 21.5% of complications due to the disease. prevalence of genetic anomaly was higher than 20% among the general population under study. | 1992 | 1344691 |