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Biomedical subjects

H O Kangro

Publications and source records attributed to H O Kangro.

At least 37 records · Page 2Linked to original sources
PubMed1990

A prospective study of viral and mycoplasma infections in chronic inflammatory bowel disease.

Seventy-two children with chronic inflammatory bowel disease were investigated for infections with various viruses and Mycoplasma pneumoniae, Chlamydia psittaci, and Coxiella burnetii to determine whether these pathogens are associated with acute onset exacerbations. Altogether 54 infections were identified serologically, of which 23 (42.6%) were associated with exacerbations. This corresponded to 24.2% of the recorded exacerbations during the study period. The respiratory pathogens accounted for 59.3% of the infections and 43.8% of these were associated with gastrointestinal symptoms. This is consistent with the observation that up to 40% of the exacerbations were associated with symptoms of antecedent or concurrent infection, most commonly involving the respiratory tract. Rubella virus, Epstein-Barr virus, and adenovirus were associated with acute exacerbations in 5 children. Thus, common pathogens were frequently associated with exacerbations and account for a large proportion of the commonly reported symptoms of a concurrent infection. The possible causal relationship between these pathogens and exacerbation of inflammatory bowel disease is discussed. Reactivation of latent herpesviruses was identified in 4 children with active disease and indicates that the converse relationship may also occur.

Acute Disease↗
PubMed1990

Protein blotting: ten years on.

Protein blotting was originally described in 1979 as an outgrowth of nucleic acid techniques, and received its commonly used designation of 'Western' blotting in 1981. The use of the technique to render electrophoresed proteins accessible for further analysis has found many roles, the most prominent being subsequent reaction with antibodies or antisera, which has many clinical and research applications. Since the initial development of the system there have been many changes to the techniques involved, but the basic principles remain unaltered. This review discusses these changes, and also provides a summary of current techniques.

Antibodies↗
PubMed1990

Lipoproteins of varicella-zoster virus.

Human fibroblast cells infected with varicella-zoster virus (VZV) showed a slight increase in lipoprotein synthesis, with the production of two major viral lipoproteins, as detected by radioimmunoprecipitation (RIP). Three bands of Mr 73,000, 90,000 and 97,000 were identified as forms of the VZV gpI glycoprotein. All three incorporated both palmitic and myristic acid, and were shown by thin-layer chromatography to contain myristic, palmitic and stearic acids. A very strong band corresponding to 7,000 Mr, which may represent the product of VZV gene 49, was detected after RIP and in VZV-infected cells, and was shown to contain almost entirely myristic acid. Several minor bands were also detected. The possible functions of the lipoproteins are discussed.

Cell Line↗
PubMed1989

Discordant results obtained on testing sera from immunocompromised patients for cytomegalovirus IgG by enzyme-linked immunosorbent assay and radioimmunoassay.

The investigation of sera from immunocompromised patients for antibody to CMV by ELISA, RIA, immunofluorescence (IF) and complement-fixation (CF) revealed discrepancies that reflected differences in test specificity rather than sensitivity and suggested that for the long-term serological follow-up of such patients it would be advisable not to rely on only a single assay procedure.

Adult↗
PubMed1988

Serological responses in varicella and zoster assayed by immunoblotting.

Acute and convalescent zoster sera taken from 11 patients with varicella and 12 patients with zoster were assayed using immunoblotting for the presence of IgG- and IgM-class antibodies to proteins present in varicella-zoster virus-infected cells. All patients exhibited a detectable virus-specific response with both antibody classes. The IgG responses involved up to 28 protein bands between 28 and 255 kilodaltons (kDa). The reactivity was particularly strong in the 78-114-kDa region, with additional bands observed with all patients at 32, 35, 66, and 220 kDa. This pattern of reactivity typically developed more slowly and was weaker and more variable in patients with varicella compared to those with zoster. The reactivity of IgM antibodies in immunoblotting was similar after varicella and after zoster. Individual sera showed up to 25 bands, with the major reactivity being directed against the 78-96-kDa region and two bands at 32 and 35 kDa. Some differences were apparent between the primary and anamnestic responses with both IgG and IgM antibodies, but this did not allow reliable discrimination of the two types of infection.

Adult↗
PubMed1988

Reduction in immunoreactivity of varicella-zoster virus proteins induced by mycoplasma contamination.

During the study of protein differences between several strains of varicella-zoster virus (VZV), two of the strains were found to be contaminated with Mycoplasma hyorhinis. Polyacrylamide gel electrophoresis showed fourteen extra bands present in MRC5 fibroblasts infected with these strains compared to other strains of VZV. A more striking difference was observed when infected cultures were used as antigens in immunoblotting. Certain viral proteins, corresponding in molecular weight to the viral glycoproteins, showed greatly reduced immunoreactivity. Experimental contamination of a mycoplasma-free strain of VZV with the glucose fermenting M. hyorhinis produced similar effects on immunoreactivity, while contamination with the arginine-hydrolysing M. orale produced no detectable effects. Given these data, it appears likely that the glucose-fermenting species induced significant changes in the VZV glycoproteins, possibly by depletion of sugars or interference in glycosylation pathways. The implications of this are discussed.

Cells, Cultured↗
PubMed1988

Detection of specific IgM in varicella and herpes zoster by antibody-capture radioimmunoassay.

A simple and sensitive M antibody-capture radioimmunoassay (MACRIA) is described which utilizes crude commercial VZV antigen and a single monoclonal anti-VZV antibody. This was compared to the immunofluorescence (IF) test for IgM antibody and was used to study IgM responses in sera from 261 patients with varicella and 220 patients with herpes zoster. With MACRIA, IgM antibodies were detected in all patients with varicella. The IgM antibodies appeared shortly after onset of rash, reached peak levels between 1 and 4 weeks after onset and then declined to low or undetectable levels in most, though not all, patients after 3 months. IgM antibodies were also detected in 98.2% of patients with herpes zoster, but the levels of IgM were significantly lower than after varicella and there was wider individual variation both in magnitude and duration of the IgM responses, in some cases only lasting 2-3 weeks. Comparison between MACRIA and IF showed good agreement in the detection of IgM antibodies following varicella. Discordant results were obtained with 13% of sera, of which 81% were taken either early or late after onset of rash and contained very low IgM levels. In contrast, 62 (28%) of the 220 sera from patients with zoster gave discordant results in the two tests, all except five being MACRIA-positive but IF-negative. The largest proportion of discordant results were obtained with sera taken more than 3 months after onset of rash, but 18 (29%) contained high IgM levels and were taken during the period of peak IgM responses. The diagnostic applications of the VZV MACRIA are discussed.

Chickenpox↗
PubMed1987

Efficacy of varicella vaccine in patients with solid tumours.

Thirty nine children with malignant disease and without antibodies to varicella zoster virus were immunised with a live Oka strain varicella vaccine. Seroconversion was shown in 24 of those who were vaccinated but five of 18 who responded to the vaccine who were followed up for over six months subsequently lost their antibodies. Of 10 children who were revaccinated, nine responded to the second dose but three lost their antibodies within six months to two years. Four children developed reactions related to the vaccine, one local and three generalised, but all these were transitory and of no clinical concern. Nine of those who were vaccinated, including four who did not respond to the vaccine, have subsequently had close exposure to varicella but none has developed the disease.

Antibodies, Viral↗
PubMed1986

The effect of staining on the immunoreactivity of nitrocellulose bound proteins.

It was found that Coomassie blue staining of proteins electroblotted onto nitrocellulose resulted in a significant decrease in subsequent immunoreactivity, relative to unstained proteins. This was not uniform, and resulted in distortion of the pattern detected by immunoreaction as well as an overall decrease in sensitivity. Staining with amido black resulted in no such alteration. Additionally, it was observed that amido black is completely leached from the nitrocellulose strip during immunoreaction, whereas no leaching is apparent with Coomassie blue. This may contribute to the observed effect of staining on immunoreactivity.

Antigen-Antibody Reactions↗
PubMed1985

Screening tests for antibodies to cytomegalovirus: an evaluation of five commercial products.

Four hundred and ninety two samples of serum from blood donors were screened for the presence of antibodies specific to cytomegalovirus using radioimmunoassay, a modified complement fixation test, and five commercially available tests: the Cetus CMV IHA, Abbott CMV total AB EIA, Cytomegalisa Stat EIA, Enzygnost EIA, and Virenz G-CMV EIA. A wide variation in results was found, with only 53.5% of the sera giving total concordance by all methods. Rates of seropositivity in the different tests ranged from 34.9% to 59.3%, with sensitivities ranging from 75.2% to 99.1% compared with the radioimmunoassay. Of 211 sera which gave positive results with four or more of the tests, none was negative by the radioimmunoassay and Abbott EIA, three were negative in Cetus IHA and Enzygnost EIA, and 11 were negative in the modified complement fixation test. Virenz G and Cytomegalisa Stat EIAs, however, gave 40 (19%) and 49 (23.2%), respectively, as negative. The results confirmed the reliability of the radioimmunoassay for the detection of the antibody status to CMV, but this test is too elaborate for a screening procedure. The Abbott EIA and Cetus IHA were found to be the most suitable for this purpose in spite of high false positive rates.

Antibodies, Viral↗
PubMed1985

Cytomegalovirus infection in dialysis patients.

We have studied cytomegalovirus (CMV) infection in 197 patients on regular dialysis treatment and 170 healthy platelet donors. Evidence of past CMV infection was found significantly more often in patients than in controls (137 of 197 v 60 of 170; p less than 0.001) at the commencement of the study. During a 12 month period 4 of the 60 dialysis patients initially found to be seronegative, but none of the 110 seronegative controls, developed primary CMV infection. Five of the 137 dialysis patients and one of the 60 controls initially found to be seropositive showed evidence of recurrent infection. Typically, there was only a transient elevation of CMV IgM antibody titer in both primary and recurrent infection. However, one dialysis patient with recurrent infection and another 5 initially seropositive patients showed persistence of CMV:IgM antibody production suggesting that they were experiencing chronic active infection. Neither primary nor recurrent infection was invariably a consequence of transfusion of blood or blood products. There were no clear-cut clinical sequelae from any of the three forms of infection documented.

Adolescent↗
PubMed1984

Detection of IgM antibodies against cytomegalovirus: comparison of two radioimmunoassays, enzyme-linked immunosorbent assay and immunofluorescent antibody test.

The sensitivity and specificity of direct antibody radioimmunoassay (RIA), M-antibody capture RIA (MACRIA), enzyme-linked immunosorbent assay (ELISA), and the immunofluorescent antibody (IFA) test for the detection of CMV-specific IgM was compared using 40 sera selected from different groups of patients. RIA, MACRIA, and ELISA gave concordant results with thirty-two sera but discordant results with eight sera, of which three were cord sera from congenitally infected babies, three were from immunocompromised patients with recurrent CMV infections, and two were from patients with lymphadenopathy and Paul-Bunnell-positive mononucleosis, respectively. RIA, MACRIA, and ELISA were of similar sensitivity with sera from adult patients, but ELISA was apparently less sensitive than RIA and MACRIA for the detection of CMV IgM in cord serum. By comparison IFA was significantly less sensitive than the other three tests. Rheumatoid factor is reactive in RIA, ELISA, and IFA but can efficiently be removed by absorption with latex-IgG beads or cross-linked human IgG.

Adult↗
PubMed1984

Improving the varicella-zoster virus: IgG radioimmunoassay procedure by the use of purified antigen.

The indirect radioimmunoassay (RIA) for detecting and assaying IgG class antibodies against varicella-zoster virus (VZV) can be improved by simple purification of the viral antigen. This is achieved by reducing binding to cellular components present in crude antigens. The purified antigen is particularly useful for testing sera that either bind excessively to normal control antigen or give equivocal results when crude antigens are used.

Antibodies, Viral↗
PubMed1984

A user's guide to the indirect solid-phase radioimmunoassay for the detection of cytomegalovirus-specific IgM antibodies.

In this review full laboratory details are given of a solid-phase indirect radioimmunoassay for the detection of specific IgM antibodies against cytomegalovirus. Practical advice is given on readily available commercial sources of reagents, a simple iodination procedure, the rapid dilution of sera under test and calculation of the results with a computer program available from the authors. Problems encountered with the assay are also detailed such as interference by rheumatoid factor, deterioration of the radiolabel and high background binding found with some sera. If these problems are avoided by the methods given in the text then the radioimmunoassay has been shown to give results of 100% specificity with 89% sensitivity for detecting congenital infection and 92% sensitivity for identifying primary cytomegalovirus infection in pregnant women.

Antibodies, Viral↗
PubMed1983

Rubella screening.

Explore the source record for details and available documents.

Antibodies, Viral↗
PubMed1982

Specific IgM class antibody production following infection with cytomegalovirus.

Specific IgM class antibody production was studied in different groups of patients with characterized cytomegalovirus (CMV) infections using a radioimmunoassay (RIA). In pregnant women, IgM antibodies were detected only following primary infection and generally persisted less than 4 months. The demonstration of CMV-specific IgM during pregnancy is therefore diagnostic of recent primary CMV infection. In patients with symptomatic CMV infections, the appearance of IgM antibody was shown to be closely related to the onset of symptoms and coincided with production of complement fixing (CF) antibody. IgM antibodies were at maximum levels 3-4 weeks after presentation but generally declined to low or undetectable levels by 3-4 months. The significance of the results of testing for CMV-specific IgM in relation to clinical and other serological findings in these patients is discussed. IgM antibody production was also demonstrated in renal transplant patients with primary infections and in 6 of 21 recipients with secondary infections. In both groups the antibodies became detectable 3-6 weeks after transplantation but the titres were much higher following primary infection. IgM antibodies persisted throughout follow-up periods of up to 2 years after transplantation in some cases.

Antibodies, Viral↗