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Biomedical subjects

G M Terry

Publications and source records attributed to G M Terry.

15 recordsLinked to original sources
PubMed1990

Diagnosis of foetal rubella virus infection by polymerase chain reaction.

We have used the polymerase chain reaction (PCR) to provide a very sensitive and unequivocal test for diagnosis of foetal rubella virus infection. RNA extracted from biopsy specimens (chorionic villi), placenta or products of conception was reverse-transcribed using a rubella virus-specific oligonucleotide primer and the cDNA was amplified by PCR. The specificity of the amplified fragment was confirmed by Southern blotting. Detection of rubella virus infection in five out of 41 clinical specimens examined by this approach was shown to be entirely consistent with clinical history and other methods of laboratory diagnosis in current use. The sensitivity of the test and the unequivocal nature of the results obtained could be invaluable in providing prenatal counselling following rubella virus infection during pregnancy.

Animals↗
PubMed1989

Detection of rubella virus in fetal and placental tissues and in the throats of neonates after serologically confirmed rubella in pregnancy.

From 35 therapeutic abortions performed because rubella had occurred at 2-19 weeks of pregnancy, 120 fetal organs, 12 specimens of mixed products of conception, and 15 placentae were tested for rubella virus. Virus was isolated from 10 out of 11 fetuses (91 per cent) from women infected at 2-8 weeks, from 5 out of 8 (63 per cent) infected at 9-10 weeks, and from 2 out of 16 (13 per cent) infected at 11-19 weeks. Hybridization tests for viral RNA on 39 fetal organs from eight cases revealed infection in four additional fetuses. Virus was isolated from only 3 out of 15 aborted placentae, but hybridization tests on six placentae revealed infection in three additional specimens. Hybridization was superior to virus isolation for detecting rubella infection in products of conception and is therefore potentially the better method for examining chorionic villus biopsies. Rubella virus was isolated from the throats of 4 out of 9 infants (44 per cent) infected during the first 12 weeks of gestation, but from none of 13 infected after 17 weeks. Infants in the latter group are unlikely to infect susceptible contacts.

Abortion, Therapeutic↗
PubMed1989

A bio-engineered rubella E1 antigen.

The major rubella envelope protein, E1, and a segment of it, comprising amino acids 207-353, have been separately expressed as fusion proteins with the IgG binding region of Staphylococcus aureus protein A in Escherichia coli. The proteins carry E1-specific antigenicity recognized by monoclonal antibodies raised against whole virus confirming that correct glycosylation is not required for antigenicity. The use of these bioengineered antigens in immunoassays for diagnosis of rubella infection and for immunization in experimental animals is described.

Amino Acid Sequence↗
PubMed1988

Diagnosis of fetal rubella infection by nucleic acid hybridization.

The efficacy of nucleic acid hybridization for the diagnosis of rubella infection in experimental and clinical materials was compared with immunoblot and virus isolation techniques. Our results showed that nucleic acid hybridization is specific and rapid but gives false-negative results when compared with conventional virus isolation in some experimental although not in clinical materials so far examined. For this reason, a failure to demonstrate rubella virus in fetal specimens by this method alone cannot yet be taken as a sole criterion for ruling out fetal rubella infection.

Abortion, Spontaneous↗
PubMed1988

Localization of the rubella E1 epitopes.

Three epitopes which react with haemagglutination inhibition and neutralizing antibodies have been located between amino acids 245-285 in the predicted amino acid sequence of rubella envelope glycoprotein E1.

Amino Acid Sequence↗
PubMed1986

First trimester prenatal diagnosis of congenital rubella: a laboratory investigation.

Acute primary maternal infection with rubella virus during pregnancy often, but not invariably, leads to the congenital rubella syndrome. Diagnosis by detection of virus specific IgM in the mother is not always possible, and in those cases in which IgM is detected the fetus has not necessarily also been infected. A method for direct, prenatal detection of fetal infection would allow more accurate early diagnosis of congenital rubella syndrome. In this study a case of suspected preconception rubella infection that was not referred until 14 weeks after the appearance of a rash was studied to determine whether a retrospective serological diagnosis of primary rubella could be made, and whether direct evidence of fetal infection could be obtained from a chorionic villus biopsy specimen by detecting virus specific antigens or ribonucleic acid (RNA) sequences. Monoclonal antibodies and a cloned complementary deoxyribonucleic acid probe were used successfully to detect antigens to rubella virus antigens and RNA sequences in the chorionic villus biopsy specimen, which was taken at 15 weeks' gestation. This method should serve as a new approach to the diagnosis of congenital rubella syndrome in utero.

Adult↗
PubMed1986

Immunological characterisation of the rubella E 1 glycoprotein. Brief report.

Three epitopes have been identified on rubella virion envelope polypeptide E 1 using monoclonal antibodies. Antibodies to two of the epitopes, E 1EP1 and E 1EP2, show both haemagglutination inhibition and neutralization activities whereas antibodies to the remaining epitope, E 1EP3, show neutralizing activity only.

Animals↗
PubMed1985

Rubella virus RNA: effect of high multiplicity passage.

Evidence for the amplification of defective interfering particles of rubella virus after passage at high multiplicity has been obtained. The process is associated with the production of subgenomic rubella RNA species.

Animals↗
PubMed1984

The relationship between the 140S antigen dose in aqueous foot-and-mouth disease vaccines and the serum antibody response of cattle.

Groups of eight or 12 cattle were injected with dilutions of aqueous saponized vaccines containing 329 760 to 7 ng of 140S O1BFS 1860 strain foot-and-mouth disease antigen per dose. Four months later the animals were subdivided into groups of four and revaccinated with vaccines containing 329 760, 9160 and 42 ng of antigen per dose. Responses were established by taking serum samples from the animals periodically and examining these for neutralizing antibody activity. The results showed that after primary vaccination the dose of antigen in vaccines influenced the earliest time of protection, the peak antibody titres attained and probably, the duration of immunity. At 21 days after vaccination the log antigen-antibody response slope was linear between 7 and 9, 160 ng, with an inclination of 0.53, indicating that every doubling of the vaccine antigen dose produced an increase of 0.16 log10SN50 in the mean serum antibody titre. The secondary response was influenced by the antigen dose in the second vaccination and to a lesser extent by that in the first vaccination also.

Animals↗
PubMed1983

Studies on the stability of foot-and-mouth disease virus using absorbance - temperature profiles.

The main immunogenic component of FMD virus harvests is the intact 140S virus particle. For the production of stable vaccines it is important to ensure that virus strains having a stable capsid should be used. The method of measuring the heat stability of FMD virus by following the increase in optical density of purified virus during capsid breakdown as the temperature is increased was described in 1964 (P. Bachrach, 1964, J. Mol. Biol 8. 348). We have investigated this technique in the hope that it might provide a means of screening virus isolates rapidly to eliminate unstable strains. Using this method we have been unable to follow the course of virus breakdown from the absorbance profile alone. A much more precise indication has been obtained by including ribonuclease in the virus sample. This enhances the optical density rise which occurs when the capsid disintegrates and the RNA becomes accessible. A sigmoid curve is obtained from which 50% breakdown temperature can be calculated. The presence of RNase does not appear to alter the temperature at which breakdown occurs since parallel samples heated in the absence of RNase showed the same behaviour when virus breakdown was measured by sucrose gradient analysis. With a given virus preparation the method gives highly reproducible results. Typical standard deviations for the 50% breakdown point were about 0.5 degrees C. However, the results are influenced by the method of purification of the virus. Virus purified by CsCl gradient centrifugation was less stable than virus purified on sucrose gradients. Thus the environmental conditions through which the virus passes during processing may affect its stability.(ABSTRACT TRUNCATED AT 250 WORDS)

Aphthovirus↗
PubMed1982

Variations in the buoyant density of foot-and-mouth disease virus strains.

Some of the factors which effect the buoyant density in caesium chloride of foot-and-mouth disease virus were investigated. Under standard conditions, the buoyant densities of a range of vaccine virus strains, representing all seven serotypes, were found to be unrelated to their potential of being formulated into effective vaccines. In some virus strains, a small amount of naturally occurring high and/or low density components were observed and these components were examined in more detail in one virus strain.

Aphthovirus↗
PubMed1978

Polysomes and polysomal mRNAs in SV40-infected CV-1 cells. In vivo observations.

SV40-specific polysomes are relatively larger than host polysomes. Both 16 S and 19 S virus-specific late mRNAs are found associated with these polysomes and they are present in a ratio of approximately 2 : 1. The rates at which these virus-specific mRNAs are translated are the same, so that the relative amounts of virus-specific polypeptides synthesized in the virus-infected cells is determined by the relative amounts of 16 S and 19 S mRNAs coding for them.

Cell Line↗
PubMed1977

Host induced modifications of Newcastle disease virus virion polypeptides.

The polypeptide composition of Newcastle Disease Virus (NDV) virions grown in two host cell cystems--chorioallantlic membrane (CAM) and BHK-21 cells--was studied. Two strains of virus were compared, one highly virulent, the other completely avirulent. No significant differences in the polypeptide composition of the two strains of virus could be detected. However, differences were found in virions grown in different hosts, the same differences being found in both strains. An additional polypeptide is found in BHK grown virus which is not present in CAM grown virus and this is associated with a decreased relative amount of nucleocapsid protein in BHK grown virus. The possibility of this new polypeptide being a degradation product of the nucleocapsid protein is discussed. BHK grown virions also contain increased amounts of a polypeptide migrating to a position which might be expected of the FO precursor glycoprotein. However, in contrast to the FO polypeptide, this polypeptide does not appear to be glycosylated.

Animals↗