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

The indirect peroxidase labelled technic for the diagnosis and research in malaria rests on the same principle than immunofluorescence test (I. F.). Homologous or heterologous antigens are incubated with patient serum in the same conditions than for I. F., and then with peroxydase, labelled, conjugate diluted 1/200. The resulting complex is colored by the diaminobenzidine method of Graham and Karnovski. The coloration is observed in light microscopy. This technic as sensitive as immunofluorescence test can be done, with a cheaper microscopic material. The possibility of studying the conjugate fixation in electron microscopy opens new direction for research.
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PMID:[Use of peroxidase markers in the research and diagnosis of paludism]. 124 96

An immunocytochemical peroxidase test (ICPT) has been developed to allow serological measurement of the antibody response to Plasmodium vivax by light microscopy. Acetone fixed P. vivax erythrocyte stages were used as source of antigen. The immunofluorescent antibody test (IFAT) was used as reference test. In testing sera from individuals infected with P. vivax in southeastern Venezuela a high correlation (100%) was obtained between the ICPT and the IFAT. There were cross reactions with sera from patients with malaria by P. falciparum but not with those from patients with other parasitic diseases. Antibody titres as measured by the ICPT showed a positive correlation with past P. vivax malarial experiences.
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PMID:An immunocytochemical test for the diagnosis of antibodies to Plasmodium vivax. 143 38

Renal specimens from Aotus monkeys were studied by light microscopy and immunohistochemistry to examine pathologic changes following vaccination with synthetic peptides corresponding to the 35-kD, 55-kD, and 83-kD asexual blood stage antigens of Plasmodium falciparum. The monkeys were vaccinated and later challenged with P. falciparum. In the monkeys vaccinated with Centers for Disease Control peptides (group I), specimens from four of six postvaccinated animals had mild to severe mesangial proliferation and two had diffuse interstitial nephritis. Specimens from three monkeys vaccinated with Colombia peptides (group II) had mild to severe mesangial proliferation and one had interstitial nephritis. In the hybrid polymer-vaccinated monkeys (group III), specimens from three animals had mild to moderate mesangial proliferation and one had severe interstitial nephritis. On the other hand, the control group immunized with bovine serum albumin (group IV) showed that specimens from three animals had mild to severe mesangial proliferation and two had severe interstitial nephritis. In the nonimmunized group (group V), specimens from three animals had moderate to severe mesangial proliferation and two had severe and mild interstitial nephritis. Immunohistochemical analysis using the peroxidase-antiperoxidase method revealed mesangial deposits of P. falciparum antigens in 11 of 14 vaccinated monkeys and in five of 10 unvaccinated controls. These results show that treatment of monkeys with prospective malaria vaccines does not increase the frequency of occurrence or of the severity of renal lesions. These data thus provide a baseline for assessing the safety of synthetic malarial vaccines in the future.
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PMID:Renal pathology in owl monkeys vaccinated with Plasmodium falciparum asexual blood-stage synthetic peptide antigens. 144 2

A direct, double- and triple-staining immunoenzymatic method detected and differentiated sporozoites by color in Anopheles stephensi salivary glands and in mixed sporozoite slide preparations. A double-staining method used beta-galactosidase- and alkaline phosphatase-labeled monoclonal antibodies to the circumsporozoite (CS) proteins of Plasmodium berghei and P. falciparum in mosquito salivary glands. The CS proteins were distinguished clearly by the blue-green and red substrate products of beta-galactosidase and alkaline phosphatase, respectively. A triple-staining method differentiated by color among a mixture of P. falciparum and two strains of P. vivax sporozoites. Monoclonal antibodies to the CS proteins conjugated to beta-galactosidase (P. falciparum), alkaline phosphatase (P. vivax variant), and horseradish peroxidase (P. vivax predominant) readily color differentiated sporozoites by the blue-green, purple-blue, and orange-brown substrate products, respectively. This assay may have potential use in malaria transmission studies, genetic crosses of variant strains of plasmodia to determine assortment of CS antigen alleles, and as a technique to determine the fate of the CS antigen in infected mosquitoes.
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PMID:Immunoenzymatic labeling of multiple plasmodial salivary gland sporozoites in a single test. 155 71

Liposomes containing lipid A induced potent humoral immune responses in mice against an encapsulated malaria antigen (R32NS1) containing NANP epitopes. The immune response was not enhanced by lipid A alone or by empty liposomes containing lipid A. Experiments to investigate the adjuvant mechanisms of liposomes and lipid A revealed that liposome-encapsulated R32NS1 was actively presented by bone marrow-derived macrophages to NANP-specific cloned T cells. The degree of presentation was related to the amount of liposomal antigen added per macrophage in the culture medium. At high cell densities, poor presentation occurred when liposomes lacked lipid A but excellent presentation occurred when the liposomes contained lipid A. Liposomes containing lipid A and encapsulated antigen also activated gamma interferon-treated macrophages to produce nitric oxide. Macrophage activation and antigen presentation occurred with liposomes that could not be detected by the Limulus amebocyte lysis assay. Intraperitoneal injection of liposomal lipid A caused a marked increase in the recruitment of immature (peroxidase-positive) macrophages to the peritoneum. On the basis of these experiments, we propose that the mechanism of the adjuvant action of liposomal lipid A is partly due to increased antigen presentation by macrophages and partly due to recruitment of an increased number of macrophages serving as antigen-presenting cells.
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PMID:Adjuvant effects of liposomes containing lipid A: enhancement of liposomal antigen presentation and recruitment of macrophages. 158 11

A method has been developed which detects malaria parasites in the salivary glands of live Anopheles stephensi. The method exploits the sugar feeding behaviour of the mosquito and requires only routine Western blotting techniques on nitrocellulose membrane (NCM). Infectivity can be determined without any direct manipulation of individual mosquitoes. Female A. stephensi were infected with the rodent malaria parasite, Plasmodium berghei, and after 14-16 d were starved of fructose overnight (12-18 h), then resupplied with fructose presented through a small piece of NCM. Mosquitoes were allowed to probe the membrane for several hours; the NCM was then removed and subjected to a standard immunoblotting protocol using an anti-P. berghei circumsporozoite protein (CSP) monoclonal antibody as the primary reagent, and a horseradish peroxidase-coupled secondary antibody. NCMs taken from cages containing infected mosquitoes showed a variable number of small black dots where individual females had probed and deposited either CSP or sporozoites. Infectivity could be detected easily from 13-14 d after feeding, and in as few as 10 mosquitoes at 19 d after infection; in one instance, infection in a single mosquito was clearly determined. After blocking with goat serum, the NCMs could be stored for 3-4 months and still provided positive reactions, offering some potential for applicability to field research studies.
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PMID:Detection of mature malaria infections in live mosquitoes. 175 48

The accuracy of visually assessing positivity for samples of field-collected Anopheles tested by enzyme-linked immunosorbent assays (ELISA) for Plasmodium falciparum sporozoites and human bloodmeals was determined during malaria field studies in Kenya. Six observers familiar with ELISAs evaluated 5,344 sporozoite ELISA samples and four observers evaluated 360 bloodmeal samples as either positive or negative based on the presence and strength of green-colored peroxidase reactions relative to controls on each microtiter plate. Interobserver agreement ranged from 97.9 to 99.8% for sporozoite samples and from 90.3 to 96.1% for bloodmeal samples. For both assays, the mean sensitivity and specificity of visual readings, compared with spectrophotometric readings, exceeded 98% when absorbance values were greater than or equal to 0.4 (on a scale of 0.0 to 2.0). Most incorrect visual readings occurred for samples with absorbance values between 0.2 and 0.4. The total percentage of samples classified correctly by visual examination ranged from 97.7 to 99.5% for the sporozoite ELISA and from 95.0 to 96.7% for the bloodmeal ELISA. Thus, there was minimal error associated with visually determining positive reactions for the ELISA assays used in malaria field studies.
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PMID:Visual assessment of sporozoite and bloodmeal ELISA samples in malaria field studies. 177 May 15

The feasibility of using fusion protein Dot-ELISA to detect the antibodies to Plasmodium falciparum was presented. Fusion protein expressed in the P. falciparum genomic DNA expression library with lambda gt11 was used as the antigen to coat the solid support nitrocellulose strips. Horseradish peroxidase conjugated with goat antihuman IgG was used as the second antibody. The enzyme activity was read by naked eyes according to the dot colour. The results by Dot-ELISA correlated well with those by IFA. The study indicated that this method was specific, sensitive, simple, and replicable. It would be valuable for further studying the usefulness of fusion protein in the immunodiagnosis of malaria.
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PMID:[Fusion protein Dot-ELISA for the detection of Plasmodium falciparum antibodies]. 206 53

Circulating antigen in sera from acute, chronic and late stages of schistosomiasis patients was detected by direct dot-ELISA with monoclonal antibody 3D8A against schistosome gut-associated cathodic antigen linked with peroxidase, the positive rates being 90.6%, 83.2% and 30.7%, respectively. No positive reactions were found with sera from patients of clonorchiasis, malaria and non-parasitic diseases. The positive rate and the circulating antigen level in EPG greater than 100 group of patients were found to be higher than those in EPG less than 100 group. Circulating antigen became negative one year after praziquantel treatment in 84.0% of patients who showed negative fecal examination, while the other patients remained positive with decreasing titers. The results indicated that the circulating antigen in sera from schistosomiasis patients of various stages can be detected by dot-ELISA with monoclonal antibody 3D8A against circulating schistosome gut-associated cathodic antigen. The authors concluded that the circulating antigen level was correlated with the intensity of infection and the efficacy of treatment.
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PMID:[Detection of circulating antigen in schistosomiasis by dot-ELISA with monoclonal antibody]. 212 22

An avidin biotin peroxidase complex enzyme-linked immunosorbent assay (ABC-ELISA) was examined for the diagnosis of malaria in a controlled area in Sudan Gezira. The titers of the ABC-ELISA coincided with those of the IFAT. The method was more sensitive than the ordinary ELISA as the final enzyme reaction was amplified through the use of the ABC system. This allowed the resulting color spots on the dried plate wells to be read clearly with the naked eye. This test can be carried out without using major electrical equipment.
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PMID:An ABC-ELISA for malaria serology in the field. 240 25


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