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Biomedical subjects

U Desselberger

Publications and source records attributed to U Desselberger.

At least 19 recordsLinked to original sources
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↗
PubMed1990

Prevalence of human parvovirus (B19) and rubella virus infections in urban and remote rural areas in northern Brazil.

Sera from inhabitants of Belém, Pará (542 sera), Brazil and of members of 3 Brazilian tribes--Tiriyo/Alto Paru (near Surinam) (212 sera), Xicrin (128 sera), and Mekranoiti (121 sera)--of different age and sex groups were tested for the presence of specific antibody against human parvovirus (B19) (RIA) and rubella virus (latex agglutination test). Parvovirus (B19) IgG was found in 42.6% of the population sample from Belém but in only 4.7 to 10.7% of the members of the tribes. Rubella virus antibody was found in 72.7% of the sera from Belém but approaching a prevalence of 85-90% in age groups above 20 years. In the tribes rubella virus antibody was detected in 36.9 to 72.6% of all sera. There were remarkable sex differences of antibody prevalence in several age groups of the population from Belém and of the tribal populations. About a quarter of the skin rashes in Belém that were not attributable to infections with rubella, measles, or arboviruses were caused by recent B19 infections.

Adolescent↗
PubMed1990

Genetic drift of equine 2 influenza A virus (H3N8), 1963-1988: analysis by oligonucleotide mapping.

Comparative analysis by RNA oligonucleotide fingerprints of total genomic RNA as well as the individual RNA segments of equine 2 influenza A virus strains from 1963, 1968, 1979, 1984, 1987 and 1988 revealed genetic diversity. Strains from the epizootic outbreak during 1978-1979 showed minor differences among their genomes. The Swedish isolates from 1979 up to 1988 showed increasing genomic heterogeneity indicating genetic drift.

Animals↗
PubMed1989

Epidemiology of human T-cell leukaemia/lymphoma virus type 1 (HTLV-1) infections in a subpopulation of Afro-Caribbean origin in England.

Epidemiological studies on neurological diseases in residents of Afro-Caribbean origin in the West Midlands region of England have identified eight patients with tropical spastic paraparesis (TSP), all of whom were found to be infected with human T-cell leukaemia/lymphoma virus type 1 (HTLV-1). The husband of one of the patients with TSP was also infected with HTLV-1 and had a T-cell lymphoma. In addition, six asymptomatic HTLV-1-infected first-degree relatives of the TSP patients have been found. By anonymous testing of over 700 sera obtained from individuals of Afro-Caribbean, African, or Asian ethnic origin, seven HTLV-1-infected individuals were detected, who were all immigrants from the Caribbean. Overall, these numbers yielded a seroprevalence of HTLV-1 infections of 3.4% among the immigrant population of Afro-Caribbean origin, which is comparable with the prevalence of HTLV-1 in Jamaica in an equivalent age and sex cohort. Sera were tested for HTLV-1 antibody by means of three different procedures: passive particle agglutination test (Serodia), indirect enzyme-labeled immunosorbent assay (ELISA; Dupont), and indirect immunofluorescence test (in-house, using HTLV-1-infected MT2 cells). The results of all three tests correlated very well with each other. HTLV-1 antibody titres in TSP patients were on the whole significantly higher than those of asymptomatic carriers, but some of the apparently healthy first-degree relatives and one anonymously tested individual had titres as high as most of the TSP patients.

Black or African American↗