Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have compared the surface radio-iodinated proteins of uninfected and Plasmodium falciparum-infected erythrocytes from natural infections of human patients. Cryopreserved infected blood from Gambian children with falciparum malaria was thawed, cultured to the middle trophozoite stage, and surface radio-iodinated. Trophozoite-infected cells were enriched about 10-fold on a Percoll gradient newly designed to separate cells based on their differential permeability to sorbitol. Infected blood was radio-iodinated and erythrocytes from the fraction enriched in parasitized cells and uninfected erythrocytes from the same sample obtained from the gradient and compared by SDS-PAGE and autoradiography. In each sample, parasitized erythrocytes contained one or more polypeptides of very high molecular weight (Mr 250 000-300 000) that were not found on uninfected erythrocytes from the same patient. These proteins were isolate-specific in size and number, suggesting that natural isolates contain a variable number of different P. falciparum phenotypes for this surface protein. In addition, these radio-iodinated surface proteins could not be extracted from the host cell membrane by the non-ionic detergent Triton X-100, but were extracted by SDS. The properties of these proteins suggest they are the equivalent for natural infections of the strain-dependent antigen previously described (Leech, Barnwell, Miller & Howard, 1984) on the surface of P. falciparum-infected Aotus erythrocytes. In addition, we observed a second parasite-dependent modification of labelled proteins on infected erythrocytes with the appearance of a new band of Mr 30 000. There were also variations in the pattern of radio-isotope labelled proteins on uninfected erythrocytes from different patients.
 ...
PMID:Identification of isolate-specific proteins on sorbitol-enriched Plasmodium falciparum infected erythrocytes from Gambian patients. 352 59

A panel of ten monoclonal antibodies made against Plasmodium chabaudi and Plasmodium yoelii infected mouse erythrocytes were used for characterization of antigens present in murine malaria. Screening of the antibodies in ELISA with different fractions of infected erythrocytes revealed both species-specific and fraction-specific monoclonal antibodies (MAbs), but also MAbs cross-reacting between the species. Two MAbs bound normal erythrocyte components. Subcellular localization of the target antigens was studied by immunofluorescence and their molecular identity by immunoblotting after SDS-PAGE. Of the MAbs to P. yoelii, one reacted with a cytoplasmic granule component of 137 k and two others reacted with vacuole-associated antigens of 26 k and 25/70/73 k, respectively. The latter antibodies cross-reacted with P. chabaudi antigens. Of the MAbs to P. chabaudi, all were species specific, one reacting with parasite surface antigens of 79 and 250 k and two with a vacuole-associated antigen of 70 k.
 ...
PMID:Studies of murine malaria antigens using monoclonal antibodies. Production, selection, and characterization of antibodies. 353 84

The effects of malaria infection on RBC sialic acids and sialoglycoproteins were studied with asexual blood-stage infections of Plasmodium knowlesi in rhesus monkeys. Glycoprotein radio-isotope labelling methods were used to compare the sialoglycoproteins of normal RBC and P. knowlesi schizont-infected RBC (SI-RBC). Tritiation of glycoproteins from SI-RBC with the standard sialidase + galactose oxidase/NaB3H4 method or standard periodate/NaB3H4 method was significantly decreased when compared to normal RBC. However, tritium uptake into glycoproteins was normal when SI-RBC were treated with 5-fold higher concentrations of both enzymes in the first labelling method, or with a 5-fold increase in the molar ratio of periodate to sialic acid in the second method. The mobility of tritiated host cell glycoproteins on SDS-polyacrylamide gels was identical for SI-RBC and normal RBC. New bands, possibly glycoproteins, of 230, 160, 90, 52, and 30 kDa were detected after labelling SI-RBC by the modified periodate/NaB3H4 method. Sialic acid analysis of normal rhesus monkey RBC (62 micrograms/10(10) RBC) revealed that 46% of the total sialic acid was N-glycolylneuraminic acid, 33% was N-acetyl-9-O-acetylneuraminic acid, and the remainder N-acetylneuraminic acid. SI-RBC collected either directly from infected monkeys or after in vitro culture of ring-infected RBC in horse serum, had increased total sialic acid (126 or 115 micrograms/10(10) RBC, respectively). The sialic acid content of infected RBC must increase during parasite development since RBC infected with ring-stage P. knowlesi had the same content as normal RBC. There was no significant difference in the ratio of the three sialic acids of SI-RBC and normal RBC. In contrast, the uninfected RBC from infected blood of different monkeys showed marked variation in sialic acid composition and generally had a lower sialic acid content than normal RBC.
 ...
PMID:Sialoglycoproteins and sialic acids of Plasmodium knowlesi schizont-infected erythrocytes and normal rhesus monkey erythrocytes. 373 41

The prevalence and pathogenesis of renal involvement was investigated in 74 patients with malarial infections. A rise in proteinuria of 150 to 5,000 mg per day was seen in 12 out of 27 patients with Plasmodium falciparum infections. SDS-polyacrylamide gel electrophoresis revealed either an increase in albumin and high molecular weight proteins alone or an increase in low and high molecular weight proteins. Serum creatinine and urea were increased in 5 patients. In P. vivax infections, 8 out of 46 patients developed a proteinuria level of up to 462 mg per day. Low and, to a lesser degree, high molecular weight proteins were increased. In one patient with quartan malaria infection, proteinuria rose as far as 432 mg per day. There was a correlation between the appearance of proteinuria and fever; however, there was no correlation between the amount of proteinuria and the height of fever. It is therefore unlikely that a rise in temperature is the only cause of proteinuria in malarial infections. The electrophoretic analyses of proteinuria indicate that in malarial infections, glomerular as well as tubular lesions may cause reversible proteinuria.
 ...
PMID:Origin of proteinuria in human malaria. 389 Jan 20

Circumsporozoite (CS) proteins of rodent (Plasmodium berghei), simian (P. knowlesi), and human (P. falciparum) malaria parasites extracted from dead and dried mosquitoes have been identified by the Western blot (immunoblot) technique. Dried mosquitoes which were laboratory-reared and infected with Plasmodium or freshly dissected sporozoites were triturated in sample reducing buffer and the extracts electrophoresed in a 10% SDS-polyacrylamide gel. After transferring the proteins to nitrocellulose, the molecular weights of both precursor and surface CS proteins of the plasmodial species were identified by probing with homologous monoclonal antibodies followed by 125I-labeled anti-mouse IgG. The molecular weights of the CS proteins extracted from dried mosquitoes were identical to those of CS proteins extracted from viable sporozoites. Immunoblot analysis is sensitive in that it can detect as few as 100 sporozoites. This technique is of epidemiological significance because it permits the identification of CS proteins of different plasmodial isolates extracted from individual, dried field-collected mosquitoes.
 ...
PMID:Identification of circumsporozoite proteins in individual malaria-infected mosquitoes by western blot analysis. 614 42

Synchronous cultures of Plasmodium falciparum were successively labelled with ((35)S)-methionine and both the supernatants and the pellets of infected red blood cells were collected. The release of TCA-precipitable material in the culture supernatants was low during the development of ring forms and trophozoites, increased during schizogony, and was maximum at the time of schizont rupture and merozoite reinvasion. Analysis of the supernatants by SDS - PAGE and autoradiography showed that both polypeptides common to the various developmental stages of the parasite and schizont/merozoite-specific polypeptides were released. Polypeptides of relative molecular mass 140 000, 82 000 and, to a lower degree, 41 000 were present in high amounts in the culture supernatants. These polypeptides have been shown to be the target of monoclonal antibodies that are able to inhibit the growth of P. falciparum cultures, and may be involved in protective immunity. The released polypeptides may also be used as target antigens in immunodiagnostic tests aiming at the detection of malaria infection.
 ...
PMID:Plasmodium falciparum polypeptides released during in vitro cultivation. 634 Aug 46

Three proteins of apparent molecular weights on reducing SDS-PAGE of 255, 59, and 53 kilodaltons have been identified as the targets on gametes of P. falciparum malaria of two monoclonal antibodies (MAbs) that act synergistically to block transmission of the parasites to mosquitoes.
 ...
PMID:Target antigens of transmission-blocking immunity on gametes of plasmodium falciparum. 635 May 27

Sera from patients with Plasmodium falciparum, P. vivax or P. ovale malaria were selected according to their high levels of antibodies against human erythrocyte membranes as measured in a microELISA. The specificity of the anti-erythrocyte antibodies in these sera and two normal sera was investigated by means of an immunoblotting technique in combination with SDS-polyacrylamide gel electrophoresis. All the patients' sera as well as the control sera contained antibodies against several erythrocyte polypeptides. As compared with normal sera, most malaria sera showed elevated levels of antibodies against polypeptides of 80K, 70K, 40K and 28K molecular weights. Two sera reacted strongly against a polypeptide with an electrophoretic mobility similar to the alpha subunit of spectrin. One serum showed strong reaction and several other sera, including normal sera, showed weak reaction against a 45K molecular weight polypeptide corresponding to actin. No pervading differences were seen in the pattern of specificities of the anti-erythrocyte ghost antibodies between sera from patients with P. falciparum, P. vivax or P. ovale infections.
 ...
PMID:Studies on the specificity of anti-erythrocyte antibodies in the serum of patients with malaria. 665 62

Lactoperoxidase-catalysed radio-iodination was used to compare the surface proteins on red cells from Plasmodium yoelii-infected with normal BALB/c mice. The profile of radio-iodinated proteins separated by SDS-polyacrylamide gel electrophoresis was different for infected blood of similar parasitaemia from mice inoculated with different doses of the parasite. Inoculation with different doses of the parasite. Inoculation with the lower dose resulted in the appearance of a major radio-iodinated protein of apparent molecular weight (Mr) 76 000 which was labelled to a similar extent on uninfected red cells from infected blood and purified multinucleate infected cells. Several minor radio-iodinated bands, with identical mobilities to the minor bands on normal BALB/c erythrocytes, were also present on red cells from this infected blood. In contrast, the higher inoculation dose produced changes in the minor labelled bands, and the band with Mr of 76 000 was absent. In this case, the minor radio-iodinated proteins of the normal BALB/c erythrocyte (with Mr of 65 000, 57 000, 48 000, 38 000 and 32 000) were replaced by a series of bands with Mr of 60 000, 50 000, 43 000 and 28 000 on both uninfected and infected red cells. These differences with inoculation dose may be related to the different duration of these infections, the development of anaemia and the extent of pathological changes at the erythrocyte surface. P. yoelii infection caused a marked loss in periodate-dependent labelling of sialoglycoproteins on most, if not all, red cells in infected blood. There was also a large decrease in galactose oxidase-dependent glycoprotein labelling with or without neuraminidase treatment. These changes in the carbohydrate groups on red cell membrane glycoproteins may be linked to the excessive loss of both uninfected and infected red cells during some malaria infections.
 ...
PMID:Characterization of surface proteins and glycoproteins on red blood cells from mice infected with haemosporidia: Plasmodium yoelii infections of BALB/c mice. 744 94

Polymerase chain reaction (PCR) primered with primers 3,4 and 5,6 was performed using DNA extracted from dried blood spot of a falciparum malaria patient from Mengpeng Township, Yunnan using four different methods, including STE-proteinase K-SDS, methanol-proteinase K-SDS, Chelex-100 and Chelex-100-proteinase K to amplify DNA of apical membrane antigen 1 (AMA-1). A 900 bp DNA band could be seen on the ethidium bromide-stained agarose gel electrophoresis of the PCR products when DNA was extracted using all the above-mentioned methods except STE-proteinase K-SDS method. DNA extracted with Chelax-100 was recommended.
 ...
PMID:[Application of Plasmodium falciparum DNA extract from dried blood spot of falciparum malaria patient in polymerase chain reaction]. 755 60


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>