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Biomedical subjects

J C Booth

Publications and source records attributed to J C Booth.

At least 55 records · Page 3Linked to original sources
PubMed1994

Quantification of cytomegalovirus DNA in blood specimens from bone marrow transplant recipients by the polymerase chain reaction.

A nested PCR system for cytomegalovirus (CMV) DNA in blood specimens from bone marrow transplant recipients is described, in which the biotinylated tritium-labelled product from the second round of PCR is quantified using streptavidin-coated fluorometric Scintillation Proximity Assay (SPA) beads (Amersham, UK). This assay has been compared with a PCR procedure based on limiting-dilution, in which the end-point is determined visually following electrophoresis in agarose gel. The two systems were shown to be equivalent in sensitivity and specificity on testing stored serial blood samples from six CMV antibody-positive allogeneic bone marrow transplant patients who developed viraemia as detected by conventional methods of virus isolation in tissue culture.

Base Sequence↗
PubMed1994

Sequence variation within the carboxyl terminus of the nucleoprotein gene of mumps virus strains.

BACKGROUND: On rare occasions, clinically apparent mumps virus infection and meningitis can be caused by vaccine virus as well as wild type strains. This has been shown by nucleotide sequencing of short regions of the viral genome. OBJECTIVES: We wished to confirm and extended these findings by investigating for strain differences within the carboxyl terminus of the nucleoprotein (NP) gene, which is known to be highly variable amongst paramyxoviruses in general. STUDY DESIGN: A 576 bp carboxyterminal fragment of NP was amplified by reverse transcriptase (RT) PCR from several different strains and was sequenced directly. RESULTS: Three Urabe vaccine variants and five clinical isolates previously classified as Urabe strains revealed the same carboxyterminal pattern for NP. Three other isolates and the Leningrad-3 vaccine strain showed characteristic differences of up to 5% compared to the Urabe strains, with U/C substitutions being predominant. CONCLUSIONS: The carboxyterminal sequence of NP varies significantly between mumps virus strains such that it can be used for differentiating between vaccine and wild-type isolates.

Journal Article↗
PubMed1993

Genomic typing of BK virus in clinical specimens by direct sequencing of polymerase chain reaction products.

Two hundred and twelve urine specimens, from several clinical groups, were examined for BK virus (BKV) using the polymerase chain reaction (PCR) to detect the VP1 region of BKV DNA. Positive results were obtained on 14 specimens from 44 post-transplant patients (31.8%), 10 specimens from 39 pregnant women (25.6%), and 5 specimens from 100 children (5%) but not on any specimens from 29 laboratory staff. Twenty-eight of the amplified BKV genomes, 19 from urine specimens, eight from culture fluid of inoculated tissue, and also one from a throat washing were directly sequenced from single-stranded templates immobilized via a biotinylated primer; it was possible to assign all to one of the four subtypes of BKV which had previously been identified on the basis of variation in nucleotide sequence of the VP1 region. Serological subgroup classification correlated with the genomic subtyping results in 21 of the isolates. The distribution of the BKV subtypes and the clinical status of the infected individuals are discussed.

BK Virus↗
PubMed1993

Lymphocyte responses and virus excretion as risk factors for intrauterine infection with cytomegalovirus.

Serological screening of pregnant women in this and a previous study identified 28 cases of primary infection with cytomegalovirus, 7 (25%) of whom transmitted the infection to their fetuses. Risk factors for intrauterine infection were: 1) age less than 20 years, 2) Caucasian rather than non-Caucasian race, 3) a weak response to cytomegalovirus antigen in the lymphocyte transformation test, and 4) the excretion of cytomegalovirus in the urine. The greatest risk was when a weak lymphoproliferative response was detected in combination with a positive result for virus isolation, in which case the chance of fetal infection was 83%. Despite these associations, there was one important anomalous result of a woman who demonstrated a strong lymphocyte response during pregnancy and a negative result for virus isolation, but who gave birth to an infected baby who developed unilateral hearing loss.

Adult↗
PubMed1993

Rapid detection of mumps virus by the polymerase chain reaction.

A procedure for detecting mumps virus in under 48 h was developed using the PCR. The sensitivity of the PCR amplification reaction and of the detection of the PCR product was significantly improved by: (i) enriching for viral template RNAs by overnight culture of the virus in Vero cells and (ii) substitution of polyacrylamide gel analysis for agarose gel electrophoresis. The technique was capable of detecting 1-20 infectious units of virus or an equivalent of 1-10 pg of mumps virus-specific plasmid DNA.

Animals↗
PubMed1991

Threshold integration of bi-amplitude signals.

This study examined the pattern of intensity integration at threshold. The stimuli studied are unique in that they have a compound peak-to-peak amplitude envelope. This waveform was partitioned into two segments, each having a different peak-to-peak magnitude (bi-amplitude). All signals in the bi-amplitude series were the same duration (100 ms). Therefore, threshold differences between these signals are due solely to the integration of intensity in the amplitude dimension. A prediction of the pattern of thresholds, based on the diverted-input hypothesis, suggested that little or no integration would occur when the amplitude difference between segments is greater than a specific magnitude. Our results indicate that there are similarities in the integration process found with variable duration signals and with bi-amplitude signals. We conclude that previous estimates of the minimum intensity level based on temporal integration data underestimates the intensity levels that can contribute to threshold. Our results suggest that there are no apparent constraints on the intensity levels that can be integrated near threshold. The auditory system integrates distributed stimulus intensity in both the time and amplitude dimensions. Temporal integration in the auditory system can be viewed as a signal process, where an enhanced internal representation is given low-level stimuli.

Acoustic Stimulation↗
PubMed1991

Sequence analysis of the V3 loop regions of the env genes of Ugandan human immunodeficiency proviruses.

Ugandan strains of human immunodeficiency virus type 1 (HIV-1) were isolated by cocultivation of peripheral blood lymphocytes from infected individuals with cord blood lymphocytes. Sequences from the V3 region of the env gene were amplified by the polymerase chain reaction (PCR) from chromosomal DNA obtained from low passage virus cultures. The PCR products from 13 Ugandan isolates were cloned into a phagemid vector and sequenced. Many isolates contained divergent V3 loop sequences and adjacent regions: diversity was associated with codon deletions or duplications and with nucleotide substitutions, especially G----A transitions. Proviruses from some of the cultures showed extensive diversity within the V3 loop sequences but others were more homogeneous. The V3 loop apices were conserved in 6 of the Ugandan proviruses and these were very similar to the equivalent regions of several Zairean proviruses. The V3 loop apices of African isolates of HIV-1 are divergent from those of North American isolates. The possible biological consequences of this divergence are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Complement-independent neutralising monoclonal antibody with differential reactivity for strains of human cytomegalovirus.

A mouse monoclonal antibody with complement-independent neutralising activity against cytomegalovirus (CMV) and reactive with the 86 kilodalton (kDa) viral glycoprotein H is described. Neutralisation tests against a range of different strains of CMV showed significant crossreactivity, but clear differences were evident between the two prototype viruses AD169 and Davis, and particularly between AD169 and several low-passage recent clinical isolates; CMV present in urine was neutralised weakly if at all.

Animals↗
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

Complement-mediated cytolytic activity associated with cytomegalovirus complement-fixing IgM antibody.

Cytomegalovirus-specific complement-fixing IgM (CMV CF-IgM) antibody was detected in 12/84 (14.3 percent) sera containing CMV-specific IgM. Higher titres were obtained by using a purified antigen preparation containing enveloped virus particles and membrane fragments when compared with a crude extract of infected cells, suggesting that the CF component of CMV IgM reacts predominantly with antigens on the surface of the infected cells. This also accounts for its complement-mediated cytolytic activity. Neither CMV-specific non-complement-fixing IgM nor CMV-specific IgG demonstrates cytolytic activity.

Antibodies, Viral↗
PubMed1988

Functional studies of cell-mediated immunity in haemophilia and other bleeding disorders.

Defects of immunoregulation which occur in haemophilia, reflected by numerical changes in T lymphocyte subsets, have been further investigated in functional studies. Polyclonal T-cell activation by the mitogen phytohaemagglutinin (PHA) and specific stimulation by cytomegalovirus (CMV) or herpes simplex type 2 (HSV-2) in previously sensitized subjects were studied in peripheral blood lymphocyte and in T4-cell-enriched cultures. Compared with 12 controls, the responses of 11 patients (nine with haemophilia A and two with von Willebrand's disease) to PHA were significantly reduced both in unfractionated and in T4-cell-enriched peripheral blood lymphocyte cultures. Reduced responses to PHA were found in HIV (HTLV III)-seronegative as well as -seropositive patients. There were no significant differences between the response of patients' unfractionated and T4-enriched peripheral blood lymphocytes to CMV/HSV-2 recall antigen and the control subjects, although there was evident variation in the magnitude of patients' unfractionated and T4-enriched lymphocyte responses.

Antigens, Viral↗
PubMed1987

Lymphocyte transformation test responses to cytomegalovirus in healthy adults from Britain and Iraq.

Lymphocyte transformation tests to CMV were carried out on young healthy adults from Britain and Iraq. Positive results were obtained in all of 28 seropositive British subjects as compared to 17 of 33 (51.5%) seropositive Iraqis; moreover, stimulation index values in the British group (mean 11.58) were significantly higher than in the Iraqi group (mean 2.84). Attempts to relate these differences to demographic characteristics, antibody response to CMV, including the response to early antigens, lymphoproliferative response to herpes simplex virus, and to phytohaemagglutinin and the presence of blocking factors were unrewarding.

Adolescent↗
PubMed1986

Increased sugar transport in BHK cells infected with Semliki Forest virus or with herpes simplex virus.

Infection of BHK cells by SFV increases the rate of uptake of [3H]MeGlc and of [3H]dGlc at approximately 2 hours p.i. Infection by HSV increases the uptake of [3H]MeGlc and [3H]dGlc at approximately 10 hours p.i.; the increased uptake is prevented by acyclovir. It is concluded that an increased sugar uptake by infected cells reflects an increased rate of transport across the plasma membrane and is the result of cellular changes caused by virus infection.

3-O-Methylglucose↗
PubMed1986

Altered acoustic cue discrimination in Broca's and conduction aphasics.

The present investigation explored the acoustic cue discrimination abilities of eight Broca's and four conduction aphasic patients and nine normal controls. A word-discrimination test was used to assess the subjects' ability to discriminate selected acoustic cues for distinctive features of phonemes. The words differed from one another by a selected minimal feature, such as stop-gap duration, duration of fricative noise, direction and extent of final format transition, or relative location of friction noise in the spectrum. Results indicated that performance for normal and aphasic subjects was poorer for altered temporal subtest items than for altered spectral subtest items. Within the spectral subtest, fewer Broca's aphasics than conduction aphasics passed the items, while 90% of the normals passed. Within the temporal subtest, fewer conduction aphasics than Broca's aphasics passed the items, while 75% of the normal subjects passed this subtest. The results support previous research suggesting that deficiencies in auditory processing of selected acoustic cues are not limited to Wernicke's aphasic individuals but may be found to a varying degree in several aphasic groups.

Adult↗
PubMed1986

Coxsackie B virus-specific IgM antibody and myocardial infarction.

The ELISA technique was shown to be group-specific for the detection of IgM antibodies against coxsackie B viruses, and probably against a wider range of enteroviruses. No evidence was obtained that recent coxsackie B-virus infection predisposes to myocardial infarction.

Antibodies, Viral↗