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U Desselberger

Publications and source records attributed to U Desselberger.

At least 73 records · Page 4Linked to original sources
PubMed1993

Detection of human parvovirus B19-specific IgM and IgG antibodies using a recombinant viral VP1 antigen expressed in insect cells and estimation of time of infection by testing for antibody avidity.

Sera from patients with symptoms of recent human parvovirus B19 (B19) infection were tested for B19-specific IgM in an immunofluorescence assay (IFA) using insect cells expressing B19 recombinant VP1 coat protein as an antigen. A highly significant correlation (P < 0.001) was found between titres obtained in the IgM IFA and the units obtained in an IgM antibody-capture RIA using plasma derived native B19 antigen. An IgG IFA using the recombinant antigen was performed on 57 sera and the antibody avidity determined. There was a highly significant correlation (P < 0.001) between the relative amounts of low avidity B19-specific IgG antibodies and time after onset of illness. This finding allows the detection of IgG to be used for diagnosing acute infection.

Animals↗
PubMed1993

Homotypic and heterotypic immune responses to group A rotaviruses in parenterally immunized sheep.

Immune responses to human rotaviruses were investigated in sheep with a view to obtaining antibodies for passive immunotherapy of humans. Eighteen adult sheep with previous natural exposure to rotavirus serotypes G3 and G6 were immunized parenterally with purified preparations of either individual rotavirus serotypes G1, G2, G3, G4 and G8, or a mixture thereof. Two additional sheep were kept as control animals with the flock. The antibody responses were measured on serial serum samples by neutralization tests. The homotypic antibody response ranged from 100-fold (rarely) up to 100,000-fold increases in titre. Heterotypic responses against serotypes G3 and G6 were demonstrated in 7/12 and 15/18 sheep, respectively, but the increases in titre were lower than the homotypic responses, ranging from 10- to 100-fold in most cases and were 1000-fold in two sheep. Interestingly, no heterotypic response against the human rotavirus serotypes was raised after 3 months; moderate titres of cross-neutralizing antibodies for the human serotypes were only observed after a third inoculation.

Animals↗
PubMed1993

A large Q fever outbreak in the West Midlands: clinical aspects.

In the spring of 1989 the largest outbreak of acute Q fever recorded in the United Kingdom occurred in Solihull and surrounding areas of the West Midlands. The diagnosis was confirmed in 147 people, mainly males of working age. Windborne spread from farmland to the south of the urban area was the most likely route of infection. Fever was the commonest symptom, seen in 101/102 (99%) cases, followed by weight loss reported by 83/101 (82%). Headache, often severe, was experienced by 69/101 (68%). The commonest respiratory symptom was breathlessness, 65/102 (64%), followed by cough, 52/102 (51%), and chest pain, 46/102 (45%). Neurological features, seen in 23% of cases, were more prominent in this outbreak than is commonly recognized. Persisting ill health 6 months following the acute episode not due to chronic Q fever was also a prominent feature of this largely urban outbreak.

Adolescent↗
PubMed1993

Antenatal survey for the seroprevalence of HTLV-1 infections in the West Midlands, England.

The sera of 3522 women who attended an antenatal clinic in Birmingham, England were tested anonymously for antibodies against HTLV-1. Samples from 5 women (0.14%) were positive, one serum showed indeterminate reactivity. Two of the women (0.06%) were born in the West Indies (of Afro-Caribbean ethnic origin), one (0.03%) in Africa (of African ethnic origin), and three (0.09%) were white Caucasian women born in the UK. Thus, HTLV-1 infection in pregnant women in the UK, though comparatively rare, is not negligible. As transmission of HTLV-1 to the newborn via breast milk has been observed and as seropositive mothers can be advised to refrain from breastfeeding or to treat their milk, the question of routine screening for HTLV-1 infection during antenatal care is discussed.

Adolescent↗
PubMed1993

Complete sequence conservation of the human T cell leukaemia virus type 1 tax gene within a family cluster showing different pathologies.

We have amplified, through PCR, the full-length tax gene of human T cell leukaemia virus type 1 (HTLV-1) derived from proviral DNA of peripheral blood lymphocytes of five first degree relatives of Afro-Caribbean origin. One patient (the father) had adult T cell leukaemia (ATL), one (the mother) tropical spastic paraparesis (TSP), and three (children) were healthy asymptomatic carriers. All five family members had identical tax nucleotide sequences as determined by direct sequencing of PCR products. This sequence was compared with tax gene sequences of an unrelated TSP patient of Afro-Caribbean origin, and of C8166 cells, and found to have one and seven nucleotide differences, respectively. At the amino acid level these three sequences differed from the HTLV-1 prototype Japanese strain (ATK-1). All sequence changes were clustered towards the 3' end of the gene. These data demonstrate the complete conservation of an HTLV-1 gene following, presumably, horizontal and vertical transmission of the virus. Clones of this gene showed more sequence variation within the TSP patient than the ATL patient, mostly consisting of point mutations; there was no conservation of mutations between the two individuals. These mutations occurred only in individual clones of the ATL patient whereas those of the TSP patient were found to be repeated in different clones. A tax-specific cytotoxic T lymphocyte response was observed in two asymptomatic carriers with low antibody titres, whereas none was detected in an individual with a high antibody level. No tax-specific sequence was identified which may have contributed to the apparently high degree of transmission from mother to children (three of five children tested) nor account for the differences between disease symptoms in the parents.

Adult↗
PubMed1993

Sequence analysis of reverse transcriptase genes of zidovudine (AZT)-resistant and -sensitive human immunodeficiency virus type 1 strains.

Sequential isolates of human immunodeficiency virus type 1 (HIV-1) were obtained from patients with AIDS on short and long term treatment with zidovudine (3'-azido-3'-deoxythymidine; AZT). The isolates were tested for resistance to zidovudine by monitoring the inhibition of syncytium formation, HIV-1-specific immunofluorescence and p24 production in C8166 cells. The reverse transcriptase (RT) genes of zidovudine-sensitive (< 1 microM) and -resistant (10 to 15 microM) strains were amplified using the polymerase chain reaction and the products were sequenced directly. The predicted amino acid sequences of the RTs of zidovudine-sensitive and -resistant isolates showed 95 to 97% identity to the corresponding sequence of HIV-1SF2 which was used as a reference. Amino acid changes at positions 41, 67, 70, 215 and 219 which are known to be associated with zidovudine resistance were present in some, but not all isolates exhibiting zidovudine resistance in vitro. This indicates that mutations in the RT of HIV-1, other than those already identified, may be involved in conferring resistance to zidovudine.

Amino Acid Sequence↗
PubMed1993

Prevalence of antibodies to Norwalk virus in England: detection by enzyme-linked immunosorbent assay using baculovirus-expressed Norwalk virus capsid antigen.

A total of 3,250 serum specimens collected in England in 1991 and 1992 were tested by an indirect enzyme-linked immunosorbent assay for antibody to Norwalk virus using baculovirus-expressed capsid antigen, and 2,382 (73.3%) were positive. The prevalence of Norwalk virus antibody differed regionally. It was lowest (24.6%) in 6- to 11-month-old infants and increased to 89.7% in persons over 60 years old.

Adolescent↗
PubMed1993

Genomic concatemerization/deletion in rotaviruses: a new mechanism for generating rapid genetic change of potential epidemiological importance.

Three variants of group A rotavirus with large changes in their gene 5 structures have been analyzed at the molecular level. The first of these, P9 delta 5, was obtained during plaque purification undertaken as part of the biological cloning of a field isolate of virus. The gene 5 homolog in this isolate migrated just ahead of the normal segment 6 RNA, giving an estimated size of 1,300 bp. Molecular cloning and sequencing of this homolog revealed it to have a single 308-bp deletion in the center of the normal gene 5 sequence extending between nucleotides 460 and 768 of the normal gene sequence. This deletion caused a frameshift in the gene such that a stop codon was encountered 8 amino acids downstream of the deletion point, giving a predicted size for the protein product of this gene of 150 amino acids compared with the 490 amino acids of its normal-size counterpart. Attempts to detect this shortened protein in virus-infected cells were not successful, indicating that it was much less stable than the full-length protein and/or had suffered a large change in its antigenicity. The second two variants, brvA and brvE, were generated in an earlier study following the high-multiplicity passage of the UKtc strain of bovine rotavirus. Polyacrylamide gel electrophoresis analysis of these nondefective variants showed that brvA had a gene 5 homolog approximately equal in size to the normal RNA segment 2 (approximately 2,700 bp) and that brvE had a size of approximately 2,300 bp. Both variants showed changes in their gene 5 protein products, with brvA mimicking P9 delta 5 in failing to produce a detectable product whereas brvE produced a new virus-specific protein approximately 80 kDa in size. Full-length cDNA clones of the brvE gene 5 homolog were isolated, and analysis of their structure revealed a head-to-tail concatemerization of the normal gene 5 sequence with the first copy of the concatemer covering nucleotides 1 to 808 and the second covering nucleotides 92 to 1579, giving a total length of 2,296 bp. Sequencing across the junction region of the two copies of the gene showed that they were joined in frame to give a predicted combined open reading frame of 728 amino acids with the amino-terminal region consisting of amino acids 1 to 258 fused at the carboxy terminus to amino acids 21 to 490.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1993

Molecular epidemiology of adenovirus conjunctivitis in Glasgow 1981-1991.

Adenoviruses isolated over a period of 10 years from patients with conjunctivitis were typed by neutralisation test using reference sera and by restriction endonuclease fragment (REF) analysis. Adenoviruses were isolated from 516 of 10,232 patients tested (5.0%); 154 were identified as type 3, 153 as type 4, 70 as type 7, 17 as type 10 and 122 as other types. At any one time, several serotypes co-circulated. The prevalence of types varied. Type 4 was not isolated in the first 2 years and then gradually increased in incidence, becoming the most frequently isolated type after 1987. Two periods of increased isolation frequency occurred: firstly from May to August 1981, when 8-28% of patients per month were found to be adenovirus-positive, with serotype 3 being predominant; and secondly from January 1989 to August 1990, when 8-20% of patients per month were adenovirus-positive, predominantly with type 4. Analysis of REFs showed that several different genotypes exist within serotypes. These also co-circulated over long periods with intermittent changes of the predominant genotype. The prototype strain Ad3GB was isolated more frequently than five other Ad3 genotypes from 1981 to 1988, after which a variant strain Ad3a was most common.

Adenovirus Infections, Human↗
PubMed1992

A modified alkaline phosphatase enzyme amplification system and its application in an HIV antigen ELISA.

Alkaline phosphatase amplification systems increase the sensitivity of enzyme-linked immunoassays (ELISAs). Here we describe a modified method by which levamisole is a component of the substrate buffer. This increases sensitivity by reducing the signal from non-specific alkaline phosphatases. The modified procedure was applied to an 'in house' HIV-1 p24 antigen capture assay and was shown to increase the sensitivity 4-fold as compared to the unmodified system. The performance of the modified amplification system is comparable to that of commercially available systems.

Alkaline Phosphatase↗
PubMed1992

Immunodominant epitopes of HIV-1 p17 and p24.

Immunodominant antibody-binding sites were mapped using overlapping synthetic peptides of the structural proteins p17 and p24 of human immunodeficiency virus type 1 (HIV-1). Using sera from HIV-1-infected individuals at a variety of disease states, three major epitopes were identified within p17 and one within p24. Antibodies which recognized these epitopes were present in all risk groups throughout all stages of HIV infection, regardless of the presence of high levels of serum p24 antigen.

Amino Acid Sequence↗
PubMed1992

The pathogenicity of two porcine rotaviruses differing in their in vitro growth characteristics and genes 4.

The pathogenicity of two rotavirus variants, 4F and 4S, obtained following adaptation to cell culture of rotavirus from a diarrhoeic pig in China, was compared by serial passage in 24 gnotobiotic piglets. The rotavirus variants have markedly different growth characteristics in vitro, and their genome profiles differ only in the relative migration of genes 4. Both cell culture-grown variants replicated to an equal extent in gnotobiotic piglets and neither caused disease, although weight gain was slightly affected in piglets inoculated with the 4F variant. During five serial pig-to-pig passages, variant 4F became highly pathogenic at the fourth and fifth passages, causing severe diarrhoea and weight loss, and premature death in two animals. Piglets inoculated with rotavirus variant 4S remained healthy during all passages although weight gain was slightly affected. Mean duration and peak infectivity titres of virus shedding were similar for both variants. Thus, variant 4F, which grew slowly and produced small plaques in vitro and had the faster migrating gene 4, was pathogenic in pigs, whereas variant 4S was apathogenic.

Adaptation, Biological↗
PubMed1992

Nucleotide sequences of normal and rearranged RNA segments 10 of human rotaviruses.

Normal and rearranged RNA segments 10 of group A rotaviruses isolated from a chronically infected immunodeficient child were amplified by the polymerase chain reaction as full-length cDNA copies, and were subsequently cloned and sequenced. Compared with the nucleotide sequence of the normal RNA segment 10, the rearranged form contains a partial non-coding duplication at its 3' end and several point mutations. The normal RNA segment 10 was similar to that of bovine rotavirus.

Amino Acid Sequence↗
PubMed1992

A serotype 10 human rotavirus.

Rotaviruses with genome rearrangements isolated from a chronically infected immunodeficient child (F. Hundley, M. McIntyre, B. Clark, G. Beards, D. Wood, I. Chrystie, and U. Desselberger, J. Virol 61:3365-3372, 1987) are the first recognized human isolates of serotype 10. This was shown by both a direct enzyme-linked immunosorbent assay and virus neutralization assays using serotype specific monoclonal antibodies. The serotype was confirmed by sequence analysis of the gene encoding VP7, which revealed a 96% amino acid homology to the bovine serotype 10 isolate B223.

Amino Acid Sequence↗
PubMed1992

Primary humoral antibody response to Coxiella burnetii, the causative agent of Q fever.

Of 147 patients with acute Q fever diagnosed during a major outbreak in Birmingham, England, in early summer 1989, 41 provided sets of sera which allowed us to make a detailed analysis of the primary humoral immune response. Antibody titers specific for Coxiella burnetii were measured by the complement fixation test and by an immunoglobulin M (IgM)- and IgG-specific indirect immunofluorescence test. The relative avidity of specific IgGs was determined by the indirect immunofluorescence test with and without treatment of antigen-antibody complexes with 8 M urea. The IgG subclass responses after primary infection and their avidities were also determined for a limited number of paired serum specimens. Specific IgM titers persisted for more than 6 months in the majority of cases and were therefore not a sufficient criterion for the diagnosis of recent infection. However, for serial samples the antibody titer ratios (IgG/IgM) and the ratios (IgG titer with treatment/IgG titer without treatment) that indicated relative avidity changed significantly, depending on the time postinfection. Within the IgG class, the C. burnetii-specific antibody response over time was almost exclusively represented by subclass 1 molecules, which thus showed affinity maturation.

Antibodies, Bacterial↗