Evaluation of a malaria antibody ELISA and its value in reducing potential wastage of red cell donations from blood donors exposed to malaria, with a note on a case of transfusion-transmitted malaria.

Background And Objectives: Blood donations are often wasted for lack of a satisfactory procedure to evaluate donors potentially exposed to malaria.

Materials And Methods: We evaluated a commercial ELISA for the detection of antibodies to malaria and compared it with an immunofluorescent antibody test (IFAT).

Results: When 5,311 sera from routine non-exposed donors were tested, 24 (0.

Diagnosis of human toxocariasis by antigen capture enzyme linked immunosorbent assay.

Aims: To evaluate an antigen capture enzyme linked immunosorbent assay (ELISA) which detects a carbohydrate epitope on the excretory-secretory (ES) antigens of Toxocara canis in clinical practice.

Methods: Serum specimens from healthy adults, patients with acute visceral larva migrans, ocular and inactive toxocariasis, and with other helminth infections were examined by two site antigen capture ELISA.

Results: Over half of the patients (19/28) with acute toxocariasis had a positive result in contrast to a small proportion of those with inactive disease (1/10) or ocular infection (2/7).

Progress toward a simplified polymerase chain reaction and its application to diagnosis of tuberculosis.

The complexity, expense, and susceptibility to contamination of the polymerase chain reaction (PCR) are all issues which need to be overcome if PCR is to be used outside of research laboratories. We addressed these problems with respect to the diagnosis of tuberculosis. First, we simplified the procedure for extracting Mycobacterium tuberculosis DNA from sputum samples.

The development and validation of a simple antigen detection ELISA for Plasmodium falciparum malaria.

A double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) is described for the detection of Plasmodium falciparum antigen. The test is based on an immunoglobulin (Ig) M capture monoclonal antibody on the solid phase and an IgG monoclonal antibody conjugated to peroxidase. The simple test takes about 2.

The spectrum of ocular toxocariasis.

Ocular toxocariasis is rare and therefore the spectrum of clinical disease is difficult to establish. We present a review of the clinical features and laboratory findings in a group of patients with positive Toxocara serology and ocular toxocariasis. The clinical spectrum was diverse and milder disease was commoner than might be supposed from reviews of the literature.

Comparison of an EBV transformed cell line and an EBV hybridoma cell line producing the same human anti-HBs monoclonal antibody.

A stable human-mouse heterohybridoma secreting human anti-HBs monoclonal antibody in continuous culture for 12 months was generated. It grew faster than the parent EBV transformed lymphoblastoid cell line (LCL) but produced the same level of specific antibody. The LCL was positive for the Epstein-Barr Virus Nuclear Antigen (EBNA), human CD 23 and contained a diploid number of human chromosomes.

Development and characterization of human anti-HBs antibodies.

Peripheral blood mononuclear cells (PBMC) from 13 healthy hepatitis B vaccines were transformed with the Epstein-Barr virus (EBV) and lymphoblastoid cell lines (LCL) producing antibodies to hepatitis B surface antigen (anti-HBs antibodies). Seven LCL and two clones secreting human anti-HBs monoclonal antibody were generated and their antibodies purified. One clone was fused with a mouse myeloma and the antibody from a cloned anti-HBs secreting heterohybridoma purified.

Epitope mapping of HBsAg using a panel of human anti-HBs antibodies.

Mapping of B cell epitopes on HBsAg was performed using a panel of human anti-HBs antibodies. Synthetic peptides representing different regions of HBsAg failed to inhibit the binding of two antibodies which recognized non-conformational HBsAg determinants in dot-blot ELISA and HBsAg polypeptide bands in immunoblot analysis. Cross-inhibition studies using five of the antibodies conjugated to horseradish peroxidase suggested that at least three different epitopes are recognised by the panel of antibodies, two of which are within the 'a' group determinant.

Studies of a common idiotype PR4 in autoimmune rheumatic disease.

A new common idiotype, designated PR4, is described. This idiotype was originally identified on a human hybridoma-derived monoclonal antibody from a patient with leprosy, which binds the major Mycobacterium leprae-derived antigen, phenolic glycolipid-1, poly(ADP)-ribose, DNA, and poly(dT). The PR4 idiotype was found in patients with systemic lupus erythematosus (SLE) (70%), rheumatoid arthritis (40%), and Sjögren's syndrome (15%).

ELISA--a possible alternative to establish a therapeutic drug monitoring system in severe and complicated falciparum malaria.

A modification of an enzyme-linked immunosorbent assay (ELISA) for the quantitative determination of plasma quinine levels is described. The test is rapid, sensitive and reproducible.

An enzyme-linked immunosorbent assay for the detection of Entamoeba histolytica antigens in faecal material.

This paper describes a method for the detection of Entamoeba histolytica antigens in stool samples using a multi-layer ELISA. The method is sensitive and specific, showing no interference with other intestinal parasites, e.g.

Comparison of an ELISA with a RIA method for serum alpha-fetoprotein determination in screening for fetal neural tube defects.

An enzyme-linked immunosorbent assay (ELISA) was evaluated for serum alpha-fetoprotein determination in the antenatal screening for fetal open neural tube defects. The ELISA was used concurrently with an existing radioimmunoassay (RIA) method until serum specimens from 5000 pregnant women, between 15 and 20 weeks gestation, had been tested. The accuracy of the ELISA was similar to that of the RIA; the median AFP values by gestational week obtained with the ELISA were, on average, 2 KIU/L higher than the corresponding RIA values; the 10th and 90th percentiles, in terms of multiples of the median (MoM), were very similar.

A critical reappraisal of the use of enzyme-linked immunosorbent assays in the study of snake bite.

The enzyme-linked immunosorbent assay (ELISA) has been the most widely used serological test in snake bite immunodiagnosis and epidemiology. The technique has been applied, however, without due consideration of the many factors which would affect an inherently sensitive test system, especially in tropical rural areas where large scale snake bite studies are usually carried out. This review discusses the effects of non-specific reactivity, cross reactivity and the quality of reagents on both the sensitivity and specificity of venom antigen and antibody detection assays.

Malaria chemoprophylaxis with chloroquine in young Nigerian children. I. Its effect on mortality, morbidity and the prevalence of malaria.

One hundred and ninety-eight Nigerian children who received weekly chemoprophylaxis with chloroquine from shortly after birth until the age of one year or two years and 185 age-matched controls were studied. Chemoprophylaxis with chloroquine was partially, but not completely, effective in controlling malaria. Clinical malaria was documented significantly less frequently in protected children than in control children, and only 9% of random blood films obtained from protected children were positive for Plasmodium falciparum while 41% of random blood films from control children were positive for this parasite.

Malaria chemoprophylaxis with chloroquine in young Nigerian children. II. Effect on the immune response to vaccination.

The immune response of 198 young Nigerian children protected against malaria by chemoprophylaxis with chloroquine to immunization with triple, poliomyelitis, measles, typhoid, meningococcal and BCG vaccines was compared with the immune response to vaccination of 185 control children. Good responses to triple, measles and BCG vaccines were shown by children in both groups; poorer responses were obtained to poliomyelitis, typhoid and meningococcal vaccines. The response to immunization of protected children was similar to that observed among control children for all the vaccines tested except for meningococcal polysaccharide vaccine.

A comparison of chloroquine and pyrimethamine as malaria chemoprophylactics in young Nigerian children.

The efficacy of chloroquine and pyrimethamine as malaria chemoprophylactics was investigated in young Nigerian children. Chloroquine resistance had not been documented in the study area; pyrimethamine resistance was probably present but uncommon. Children who received weekly chemoprophylaxis with pyrimethamine had a lower prevalence of malaria parasitaemia and malaria antibodies than children who received weekly chemoprophylaxis with chloroquine.

Serum C-reactive protein levels and falciparum malaria.

A microplate ELISA was developed to measure C-reactive protein (CRP) and it was used to establish the relationship between CRP levels and malaria. Highest serum CRP levels were found in African patients with high Plasmodium falciparum parastaemia. However, even African children with lower parasitaemia had higher CRP levels than others without parasitaemia.

Purified Trypanosoma cruzi specific glycoprotein for discriminative serological diagnosis of South American trypanosomiasis (Chagas' disease).

Chagas' disease, leishmaniasis, and Trypanosoma rangeli infection are endemic and their distributions overlap in vast regions of South and Central America. Serological cross-reactivities can confuse epidemiological studies of these infections, and their differential diagnosis has been assigned a high priority by the World Health Organisation. A lectin-affinity-purified, 90,000 molecular weight glycoprotein (GP90) is present in the known principal strains (zymodemes) of Trypanosoma cruzi and absent from Leishmania and T rangeli.