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Biomedical subjects

R J Hayes

Publications and source records attributed to R J Hayes.

7 recordsLinked to original sources
PubMed1992

Cooperative binding of the red clover necrotic mosaic virus movement protein to single-stranded nucleic acids.

The movement protein of red clover necrotic mosaic dianthovirus was produced in Escherichia coli using an expression vector. Gel retardation analysis and u.v. cross-linking studies showed that the movement protein bound cooperatively to ssRNA and ssDNA, but not to dsDNA. Binding competition experiments established that the movement protein bound to ssRNA and ssDNA with similar affinities and that the binding was not sequence-specific in the experimental conditions employed. A truncated movement protein lacking the C-terminal 88 amino acids was also shown to bind to ssRNA.

Binding, Competitive↗
PubMed1992

Complete replication of a satellite RNA in vitro by a purified RNA-dependent RNA polymerase.

The 334 nucleotide R satellite RNA was used as a template for purified RNA-dependent RNA polymerase (RdRp) from cucumber mosaic virus-infected tobacco plants. The products of the reaction were dsRNA and positive-strand RNA of the same size as the R satellite RNA. Similar products were obtained when T7 RNA polymerase positive-strand transcripts of a cDNA clone of the satellite RNA, designed to have the same 5' and 3' ends as the satellite RNA, were used as templates. The formation of the positive strands demonstrates complete replication of the satellite RNA. A positive-strand transcript with 65 and 255 additional nucleotides at the 5' and 3' ends of the satellite RNA respectively was also utilized as a template by the RdRp, but only dsRNA was formed. However, no products could be detected when the RdRp was programmed with transcripts corresponding to the negative-strand satellite RNA, either with no additional terminal nucleotides or with 24 and 310 additional nucleotides at the 5' and 3' ends respectively.

Base Sequence↗
PubMed1992

Case-control studies of severe malaria.

The majority of children infected with Plasmodium falciparum in areas of stable endemicity do not develop severe, life-threatening disease. It is important to identify risk factors for the minority who do. Case-control studies in which children with severe disease are compared with children with non-severe disease and with community controls, avoid some of the ethical and logistical problems inherent in such an undertaking. This paper discusses methodological aspects of case-control studies of severe malaria including case and control definitions, selection of cases and controls, potential risk factors, sample size calculations and analysis. Although specifically concerned with malaria, many of these issues are equally relevant to case-control studies of other infectious and parasitic diseases in a tropical environment.

Case-Control Studies↗
PubMedDate not supplied

Use of prednisolone in the treatment of HIV-positive tuberculosis patients.

Corticosteroids are beneficial in the treatment of some forms of tuberculosis, but their role in TB affecting HIV-positive patients is not clear. During a cohort study of tuberculosis patients in Lusaka, Zambia, prednisolone was prescribed for specific indications. Six of 47 (13 per cent) of patients who received prednisolone early in treatment developed herpes zoster, compared with 2 of 118 (2 per cent) of those who did not. Three patients who received prednisolone developed Kaposi's sarcoma, compared with none who did not. At 2 months patients who had received prednisolone showed a greater improvement in generalized lymphadenopathy and cough. Controlled studies of the risks and benefits of administration of corticosteroids to HIV-positive TB patients are urgently needed.

AIDS-Related Opportunistic Infections↗