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M J Cardosa

Publications and source records attributed to M J Cardosa.

11 recordsLinked to original sources
PubMed1992

IgM capture ELISA for detection of IgM antibodies to dengue virus: comparison of 2 formats using hemagglutinins and cell culture derived antigens.

The highly sensitive AFRIMS format IgM capture ELISA for the diagnosis of dengue virus infections requires the use of mouse brain derived hemagglutinins and consequently also the use of 20% acetone extracted normal human serum to eliminate high background. These reagents are not always easily available and we have thus compared the AFRIMS format with another published format which uses cell culture derived antigens (culture fluid, CF, format) in order to determine if it is reasonable to use cell culture derived antigens in situations where hemagglutinins and normal human serum are difficult to obtain. The study shows that using AFRIMS results as the reference point, the CF format described here has a sensitivity of 90% and a specificity of 96%.

Antibodies, Viral↗
PubMed1992

Mumps encephalomyelitis.

A 7-year-old Indian girl developed complete paralysis of her lower limbs and acute urinary retention 10 days after suffering from mumps. Encephalomyelitis due to mumps was not suspected initially since it is a rare complication of mumps, although relatively well-documented. However, the preceding history of parotitis and the presence of mumps-specific IgM in both blood and cerebrospinal fluid led to the diagnosis. The initially severe acute neurological deficits resolved completely three months after onset of her illness. Serological investigations were helpful in diagnosing neurological complications of mumps in this case, and especially where there is no preceding parotitis.

Child↗
PubMed1991

A serological study of Japanese encephalitis virus infections in northern Peninsular Malaysia.

This study describes the status of viral encephalitis in Perak, Malaysia during the year 1990. In addition, 14 cases selected from Penang and Perak during the years 1989 and 1990 are presented, with data showing titers of neutralizing antibodies against Japanese encephalitis virus (JEV) and dengue 2 virus, titers of antibodies against JEV and dengue virus antigens as determined by DEIA, and a comparison of these with the presence of IgM to JEV and dengue virus. These data show that there probably is far more viral encephalitis due to JEV in Malaysia than the national figures reflect.

Adolescent↗
PubMed1991

Dot enzyme immunoassay: an alternative diagnostic aid for dengue fever and dengue haemorrhagic fever.

A dot enzyme immunoassay (DEIA) for the detection of antibodies to dengue virus was tested for use as a tool in the presumptive diagnosis of dengue fever and dengue haemorrhagic fever. Paired sera from the following groups of patients were tested using the DEIA and the haemagglutination inhibition (HI) test: those with primary dengue fever; those experiencing a second dengue infection; and febrile patients who did not have dengue. The data obtained show that the DEIA can be effectively used at a serum dilution of 1:1000 to confirm presumptive recent dengue in patients with a second dengue infection. However, demonstration of seroconversion proved necessary for patients with primary dengue. At a serum dilution of 1:1000 the DEIA has a specificity of 97.3%. The role of this simple and rapid test in improving the effectivity of programmes for the control of dengue virus infection is discussed.

Adult↗
PubMed1988

Development of a dot enzyme immunoassay for dengue 3: a sensitive method for the detection of antidengue antibodies.

Partially purified DEN3 virus was used as antigen in a sensitive dot enzyme immunoassay (DEIA) for the detection of antibodies to flavivirus antigens. We describe here the method used to prepare and optimise the antigen-bearing nitrocellulose membranes and present the results obtained from screening 20 acute phase sera from patients shown to have had recent dengue infections by the haemagglutination inhibition (HI) test. Sixteen pairs of acute and convalescent sera from dengue-negative patients had no detectable antibody to dengue virus by HI. These were shown to have no antibody detectable by DEIA. Sera positive for dengue antibodies by HI had DEIA titers ranging from 10 to several thousand times greater than the titers detected by HI.

Antibodies, Viral↗
PubMed1988

A dot enzyme immunoassay for dengue 3 virus: comparison with the haemagglutination inhibition test.

A dot enzyme immunoassay (DEIA) was used to determine the levels of antibody to dengue 3 virus in the acute and convalescent sera of febrile patients with a clinical diagnosis of dengue fever or dengue haemorrhagic fever. The antibody titres were compared with titres determined by the haemagglutination inhibition (HI) test. The results of the study showed that, besides being more simple to perform, the DEIA is in order of magnitude more sensitive than the HI test. Furthermore, the data suggest that it is possible to use a single dilution as a cutoff point to predict with reasonable accuracy, if a patient has had a recent dengue infection. The DEIA test for antibodies to dengue virus is an appropriate technology highly suitable for rapid diagnosis and surveillance in developing countries.

Dengue↗
PubMed1979

Isolation and analysis of chemosensory behavior mutants in Drosophila melanogaster.

A behavioral countercurrent paradigm has been developed for assaying the chemotactic responses of wild-type and mutant Drosophila melanogaster adults. Oregon R males avoid both quinine sulfate and NaCl, whereas Oregon R females reject the quinine salt but are attracted to NaCl when tested in this paradigm. Wild-type behavior is sufficiently reproducible to allow identification of mutants affecting chemotaxis, and 12 such mutants, in six complementation groups, have now been isolated. Three of the mutants respond abnormally to NaCl, two in one complementation group with atactic behavior (no chemotaxis) and the other, in a separate group, with a mistactic response (attraction to the stimulus). Four mutants in another group respond mistactically to quinine sulfate. Of the remaining mutants, two in one group behave atactically and three, in two groups, respond mistactically to either chemical stimulus. Several of the mutants also show abnormal behavior in a proboscis extension assay when tested individually with sucrose solutions.

Animals↗