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Biomedical subjects

P Morgan-Capner

Publications and source records attributed to P Morgan-Capner.

124 records · Page 7Linked to original sources
PubMed1980

Rubella antibody measured by radial haemolysis. Characteristics and performance of a simple screening method for use in diagnostic laboratories.

A simple method for preparing radial haemolysis gels for rubella antibody screening is described. In use it gave clear zones of haemolysis when a standard serum was tested at dilutions down to 5.6 i.u./ml rubella antibody. In five laboratories 8404 sera were screened by the method and the results were read by comparing zones of haemolysis with that of a standard serum diluted to contain 15 i.u/ml antibody. A zone greater than or equal to 15 i.u./ml, indicating immunity, was given by 7433 (88.4%) of the sera. No zone indicating susceptibility was seen with 748 (8.9%) sera. Small zones, less than 15 i.u./ml standard, were given by 189 (2.2%) sera, and in only 34 cases (0.4%) did non-specific haemolysis interfere with the test readings. Further testing of the radial haemolysis interfere with the test readings. Further testing of the radial haemolysis negative and low positive sera by the haemagglutination inhibition test gave rise to some discrepant results which are discussed.

Antibodies, Viral↗
PubMed1980

Rubella-specific IgM detection using Sephacryl S-300 gel filtration.

Sephacryl S-300 has been compared with Sephadex G-200 in the fractionation of sera for the detection of rubella-specific IgM. No difference in sensitivity was found with sera that had low titres of rubella-specific IgM. Sephadex G-200 was apparently more sensitive with some sera which had high titres of rubella-specific IgM due to the contribution of rubella-specific IgA. Sephacryl S-300 offers considerable advantages in ease and speed of preparation, and as it is a more rigid gel higher flow rates can be obtained. Sera may be fractionated in 2.5 hours on Sephacryl S-300 compared with 7-10 hours on Sephadex G-200.

Antibody Specificity↗
PubMed1980

Nature of circulating immune complexes in infective endocarditis.

Two percent polyethylene glycol (PEG) precipitation was found to be a useful method for detecting circulating immune complexes (CIC) and could be used diagnostically to implicate infective endocarditis. Complexes consisting of a least Clq, IgG, and IgA were typically detected in sera from patients with infective endocarditis. Serial studies showed that CIC detection and measurement could be used to monitor clinical progress. Successful clinical improvement was reflected by decreasing CIC levels and the disappearance of rheumatoid factor, and, where increasing amounts of CIC were found, this may indicate situations where treatment was insufficient or inappropriate. There was specific free antibody demonstrable in the serum of six out of nine patients against their own infecting organisms, but attempts to identify the specificity of the complexed antibody as being directed against these organisms or their extracellular products failed. We could not detect any radioactive precipitin arcs, indicative of the free antibody also being in the complex, between the F(ab')2 preparation from the complex and the electrophoresed bacterial antigens in a radio-immunoelectrophoresis system. Eleven out of 13 sera that contained Clq, IgG, and IgA in their complexes also contained rheumatoid factor. Immunisation against the patient's own persisting CIC may explain this phenomenon.

Adult↗
PubMed1980

A fatal case of Epstein-Barr virus infection with jaundice and renal failure.

A fatal case of Epstein-Barr virus infection in a 17-year-old male is described. The patient presented with an illness clinically typical of infectious mononucleosis but death followed development of renal failure, jaundice and pulmonary failure. There was no absolute lymphocytosis nor a significant number of atypical mononuclear cells in his peripheral blood. However, heterophile antibody and Epstein-Barr virus-specific IgM were present.

Acute Kidney Injury↗
PubMed1979

A comparison of three tests for rubella antibody screening.

Sera from 1000 women attending antenatal clinics were screened for the presence of rubella antibody by haemagglutination inhibition (HI), single radial haemolysis (SRH), and enzyme-linked immunosorbent assay (ELISA). With 925 sera concordant results were obtained with all three tests. There were 46 false-negative HI tests due to the necessity of allowing for residual non-specific inhibitors. With SRH there was one false positive and three that were negative by SRH but HI- and ELISA-positive. By ELISA 14 sera gave a false-positive result (OD 405 nm greater than or equal to 0.2). Ten of these could be eliminated by taking an OD 405 nm of 0.5 as the threshold but then another 10 sera became false negatives.

Antibodies, Viral↗
PubMedDate not supplied

Prenatal detection of rubella-specific IgM in fetal sera.

Serum specimens were obtained by fetoscopy at 19-25 weeks' gestation from four fetuses whose mothers had had confirmed rubella earlier in pregnancy. They were tested for rubella-specific IgM by antibody capture radioimmunoassay. No specific IgM was detected in one fetus and a healthy infant was delivered at term. Specific IgM was detected in the other three fetuses. In one case the level was low (1 unit) and this pregnancy went to term resulting in a neonate with clinical and laboratory evidence of congenital rubella infection. The remaining two fetuses had 2.8 and 2.4 units of specific IgM and the pregnancies were terminated. Blood obtained from these two fetuses after abortion showed levels of 5.4 and 2.9 units respectively. No specific IgM was detected in sera from eleven other fetuses aborted because of maternal rubella but five of these cases were terminated before 19 weeks and in five the interval between rash and abortion was three weeks or less. The results show that the human fetus can produce detectable specific IgM antibody by 19-20 weeks' gestation after exposure to rubella several weeks earlier. However, a larger study is required to define the reliability of fetoscopic blood sampling for the diagnosis of intrauterine infection.

Amniotic Fluid↗
PubMedDate not supplied

Rubella-specific IgG1 avidity: a comparison of methods.

Two methods of determining the avidity of specific IgG1 were compared with sera from different categories of rubella infection. Both methods were based on an antiglobulin enzyme-linked immunosorbent assay. In one method the absorbances were compared with and without diethylamine (DEA) in the serum diluent over a range of serum dilutions and the difference between the dilution curves measured (DEA-shift). In the other, the absorbances at a single serum dilution were compared with and without urea in the wash fluid used after the antigen/serum incubation (avidity index). Various concentrations of DEA were also assessed in the avidity-index method, as this method is simpler to perform. The DEA-shift method was shown to be more sensitive for diagnosing recent primary rubella or immunization by demonstrating specific IgG1 of low avidity. The avidity-index method, however, was more specific when sera from cases of reinfection or non-specific rubella IgM reactivity were tested. 35 mM DEA was found to be the optimal concentration of DEA when DEA was substituted for urea in the avidity index method.

Antibodies, Bacterial↗