Search PubMed⌕ Search

Biomedical subjects

R S Tedder

Publications and source records attributed to R S Tedder.

At least 163 records · Page 9Linked to original sources
PubMed1982

The production of monoclonal antibodies to rubella haemagglutinin and their use in antibody-capture assays for rubella-specific IgM.

Mice were immunized by three intraperitoneal and one intravenous injection of rubella haemagglutinin. Splenocytes from these mice were fused with the cells of a syngeneic myeloma cell line, and following culture for various periods of time, single-cell clones were derived by the technique of limiting dilution. A total of 139 clones were derived from 13 parent hybrid cultures. To date, four of these cloned cultures have been propagated as ascitic tumours in mice. The preparation of IgG from ascitic fluid and labelling of this antibody with 125I is described. Results indicate that the use of labelled monoclonal antibodies as indicator reagents in solid-phase IgM antibody capture assays for the detection of rubella-specific IgM results in enhanced performance of these tests.

Animals↗
PubMed1981

Contrasting patterns and frequency of antibodies to the surface, core, and e antigens of hepatitis B virus in blood donors and in homosexual patients.

An attempt was made to assess the significance of the relatively frequent low-titre positive reactions in radioimmunoassays for antibody to hepatitis B surface antigen. Serum specimens negative for surface antigen were assayed for antibodies to the surface, core, and e antigens of the Hepatitis B virus. Two populations were studied - one of low hepatitis B incidence (2000 blood donors) and one of high incidence (200 male patients attending a clinic for sexually transmitted diseases). The validity of some singly occurring low-titre anti-HBs and anti-HBc reactions is questioned, and the occurrence of positive reactions unrelated to previous hepatitis B infection inferred.

Antibodies, Viral↗
PubMed1981

Detection of antibody to varicella-zoster virus by competitive and IgM-antibody capture immunoassay.

A simple, sensitive, and specific competitive solid phase immunoassay for antibody to varicella-zoster virus (anti-VZV) is described. The assay uses reagents that can easily be prepared and is sparing of viral antigen. Using a solid phase coated with sheep IgG from a serum raised against human mu-Fc, the same reagents will accurately detect anti-VZV IgM. The competitive assay divided sera from children from adults into immune and nonimmune groups that closely correlated with a history of previous VZV illness. It was not affected by the presence or absence of antibody to other herpes viruses. The IgM antibody capture assay demonstrated the presence of anti-VZV IgM in sera from patients with both varicella and zoster and gave negative results in patients with infections unrelated to VZV and in healthy blood donors.

Adult↗
PubMed1981

Development of an enzyme-linked immunosorbent assay (ELISA) for hepatitis B e antigen and antibody.

Horseradish peroxidase has been conjugated with human immunoglobulin containing antibody to hepatitis B e antigen (anti-HBe). This was used in a solid-phase 'sandwich' enzyme-linked immunosorbent assay designed for reading by eye, to test sera for HBeAg and anti-HBe. Optimum conditions for preparing the conjugate and for performing the test are described. Results of testing hepatitis B surface antigen (HBsAg)-positive sera were compared with those obtained using a sensitive solid-phase radioimmunoassay. The enzyme assay provided a simple and sensitive method of testing for HBeAg and anti-HBe, and correlated well with the radioimmunoassay.

Antibodies, Viral↗
PubMed1981

Antibody capture radioimmunoassay for anti-rubella IgM.

An M-antibody capture radioimmunoassay (MACRIA) for anti-rubella IgM was developed. Under optimum conditions positive serum specimens bound up to 20 times as much radioactivity as negative specimens. Positive reactions were expressed in arbitrary units/ml by comparison with a calibration curve derived from results obtained with dilutions of a standard serum. The specificity of the assay was confirmed by testing IgM and IgG rich fractions of positive sera. One hundred and forty specimens from blood donors, patients whose sera contained rheumatoid factor and patients with acute, non-rubella, virus infections were tested by MACRIA. No significant non-specific reactions were detected. Paired sera from acute rubella (25 patients) and individual sera from suspected rubella (69 patients) were tested for anti-rubella IgM by MACRIA and by haemagglutination inhibition following sucrose-density-gradient fractionation. There was close agreement between the two methods. The capture assay was more sensitive and could be used to detect the weak IgM response in women given RA 27/3 vaccine. After the natural infection, the MACRIA was strongly positive for two months and remained weakly so for a further two months. Repeat testing of sera demonstrated good reproducibility of the assay. MACRIA proved a simple, sensitive and specific test for anti-rubella IgM and compared favourably with currently used techniques.

Animals↗
PubMed1981

IgM-antibody response to the hepatitis B core antigen in acute and chronic hepatitis B.

A solid phase M-antibody capture radioimmunoassay (MACRIA) and a serum fractionation method were used to quantitate the IgM response to the hepatitis B core antigen (IgM anti-HBc) in acute and chronic hepatitis B infections. Antibody to the core antigen was predominantly of the IgM class during the acute phase of hepatitis B. Resolving acute infections remained positive by MACRIA, but at decreasing levels, for as long as 6 months. IgM anti-HBc persisted in HBsAg carriers but at levels very much lower than seen in acute infections. There was no correlation of IgM anti-HBc with severity of chronic liver disease in carriers. Measurement of IgM anti-HBc by MACRIA enabled accurate identification of acute hepatitis B on single serum specimens.

Antibody Formation↗
PubMed1981

Are many women immunized against rubella unnecessarily?

Radial haemolysis (RH) was used to test sera for immunity to rubella from 1317 patients attending a general practice. One hundred and forty-one (10.7%) were treated as susceptible and offered an attenuated virus vaccine (RA 27/3). Pre-immunization sera from 43% of these patients were reactive at low levels in RH (less than 15 international units rubella antibody per ml). Pre- (S1) and post- (S2) immunization sera from 66 vaccinees were studied in detail. Antibody was detected by RH, haemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA), and the specific IgM response was measured by a solid-phase M-antibody capture radioimmunoassay (MACRIA). The vaccine-induced IgM response was only detected if the S1 serum was non-reactive by all tests for rubella antibody. It was weaker than that seen following wild virus infection. It could be detected reliably for six weeks, and in most cases for nine weeks, after immunization. In contrast, patients with S1 specimens reactive by RH, HI or ELISA never showed an IgM response in the S2 specimen despite "significant' antibody rises often being present. It was considered that an IgM response to RA 27/3 was the best indicator of pre-immunization susceptibility to rubella. The failure of many vaccinees to make an IgM response implied that a significant proportion were already immune. It is suggested that the threshold for a report of immunity to rubella could be lowered from 15 i.u. antibody per ml and so fewer women immunized without vaccine being withheld from those who need it.

Adolescent↗
PubMed1980

The role of rheumatoid factor in an electron microscope study of hepatitis B antigens.

An immune electron microscopic (IEM) study of the hepatitis B e antigen (HBeAg) system has shown that rheumatoid factor (RE) can be an important complicating factor when examining preparations containing multiple antigenic specificities. For example, in the presence of RF, mixed immune complexes were produced that suggested HBeAg might be antigenically related to either Dane particles or cores. When RF was removed, however, the putative HBeAg--anti-Hbe complexes showed no relationship with any other hepatitis B component. It has been shown that RF can have a positive practical application in IEM by using it to link preformed marker complexes to immune complexes which do not contain morphologically recognizable antigen.

Antigen-Antibody Reactions↗
PubMed1980

Detection by radioimmunoassay of IgM class antibody to hepatitis B core antigen: a comparison of two methods.

A solid-phase radioimmunoassay (RIA) for IgM anti-HBc is described. The assay (anti-mu RIA) is based on the adsorption of IgM to a tube coated with sheep antibody to the human IgM mu-chain. The adsorbed immunoglobulin is assayed for anti-HBc activity. Positive reactions in the test are shown to be due to IgM antibody, and a confirmation blocking test is described. Reactivity of test sera can be quantitated by comparison with standard sera containing known levels of IgM anti-HBc. Sera assayed for IgM anti-HBc by both the anti-mu RIA and a method employing serum fractionation and competitive RIA gave similar results. Rheumatoid factor (RF) alone did not react in the anti-mu RIA, but reactivity could be generated in the presence of RF and preformed aggregates of IgG anti-HBc.

Antibodies, Viral↗
PubMed1980

Hepatitis B carrier state produced by a blood transfusion.

A renal transplant patient was infected by a transfusion of blood from a chronic carrier of hepatitis B and he also became a symptomless carrier. Stored sera enabled detailed retrospective measurement of the rate of decline of passively transferred HBsAg, anti-HBc, and anti-HBe. Active HBsAg production was detected after two months and anti-HBc after six months; neither HBe nor anti-HBe was actively produced although there were many 42 nm HBV particles in the patient's serum.

Adult↗
PubMed1979

Characterization of 'e' antigen associated with hepatitis B.

Hepatitis B 'e' antigen (HBe) from the serum of a chronic carrier of HBsAg has been partially purified and characterized. It behaves as an acidic protein, pI 4.5--5.0, which is thermolabile and sulphydryl-sensitive. In serum it usually has a flotation density 1.3 g/cm3, but is sometimes found at density 1.15 g/cm3 because of its association with lipid. HBe from serum is polydisperse on gel filtration although most antigen is recovered with a nominal molecular weight of 3 x 10(5) Daltons. In contrast, in the presence of chaotropic ions, the bulk of serum HBe is found as a species of 3 X 10(4) Daltons previously detected in small amounts under non-dissociating conditions. This suggests that the larger material is formed by non-covalent association of the 3 X 10(4) Dalton species either with itself or other serum components. This would include IgG, although there is no evidence that HBe itself bears immunoglobulin determinants. Analysis of HBe precipitins by polyacrylamide gel electrophoresis under reducing and dissociating conditions suggests that its component polypeptide chains are about 1.7 X 10(4) Daltons.

Adult↗
PubMed1978

Liver enzyme concentrations as measure of possible infectivity in chronic asymptomatic carriers of hepatitis B.

Fifty-two British-born blood donors who were chronic carriers of hepatitis B surface antigen (HBsAg) were tested for the presence of hepatitis B e antigen (HBeAg) and antibody to HBeAg by an immunoradiometric assay. The presence of HBeAg was closely associated with a slight rise in serum liver enzyme concentrations, a high HBsAg titre, and male sex. We suggest that the finding of persistently raised serum liver enzyme concentrations in an asymptomatic HBsAg carrier might be useful as a likely indicator of HBeAg and high infectivity.

Carrier State↗
PubMed1978

Testing for e antigen and e antibody by immunodiffusion.

A rapid and reproducible micro e-ID test is described which allows two out of three HBsAg carriers to be classified as e-Ag or e-Ab. The majority of the remaining one-third of carriers are e-Ab as shown by e-RIA though a few will be e-Ag positive carriers by e-RIA.

Antibodies, Viral↗