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R C Matthews

Publications and source records attributed to R C Matthews.

At least 55 records · Page 3Linked to original sources
PubMed1993

Application of the polymerase chain reaction to the diagnosis of candidosis by amplification of an HSP 90 gene fragment.

A 317-base pair (bp) fragment of the Candida albicans heat shock protein 90 (HSP 90) gene was amplified by the polymerase chain reaction (PCR) for detection of C. albicans DNA in clinical specimens. One hundred specimens were examined including swabs (39), urines (36), peritoneal fluid (9), pus (8) and blood or serum (8): 23% gave positive results with routine culture, 31% with extended broth culture and 37% with PCR. The amplified product was identified by hybridisation with a radiolabelled internal probe and their restriction enzyme digest patterns (SspI, HaeIII, EcoRI, RsaI and XhoI), which could be predicted from the known sequence of HSP 90. C. albicans DNA gave the characteristic 317-bp band and specifically hybridised with restriction enzyme-digested candidal DNA. DNA from other sources intermittently gave multiple faint bands especially in the presence of high concentrations of DNA, but these could be readily distinguished. The method was sensitive to 50 pg of DNA (5 pg with radiolabelled probing) and 100 cfu of C. albicans.

Candida albicans↗
PubMed1993

Application of polymerase chain reaction to fingerprinting Aspergillus fumigatus by random amplification of polymorphic DNA.

A new method for fingerprinting Aspergillus fumigatus by random amplification of polymorphic DNA (RAPD) by using single primers with arbitrary sequences is described. Five primers were examined with 19 isolates from six patients with aspergilloma as well as with A. fumigatus NCPF 2109. Two of the primers (GCT GGT GG and GCG CAC GG, 5' to 3') gave adequate discrimination between isolates, generating five and six types, respectively. Combination of the results obtained with each of these two primers generated 12 types. This compares very favorably with immunoblot fingerprinting and XbaI-generated restriction fragment length polymorphisms on the same isolates. Typeability and reproducibility were good with RAPD, and RAPD was less labor-intensive than immunoblot fingerprinting. RAPD typing results suggested that aspergillomas sometimes contain isolates of more than one type.

Aspergillosis↗
PubMed1992

Is Bordetella pertussis clonal?

OBJECTIVE: To establish whether Bordetella pertussis is essentially clonal. DESIGN: Analysis of restriction fragments of XbaI digests of DNA from clinical and control isolates of B pertussis by pulse field gel electrophoresis. MATERIALS: 105 isolates of B pertussis: 67 clinical isolates from throughout the United Kingdom and 23 from Germany (collected during the previous 18 months); vaccine strains 2991 and 3700; and 13 control isolates from Manchester University's culture collection. MAIN OUTCOME MEASURES: Frequency of DNA types according to country of origin and classical serotyping. RESULTS: 17 DNA types were identified on the basis of the variation in 11 fragments, banding at 200-412 kilobases; 15 types were found in the clinical and control isolates from the United Kingdom and seven in those from Germany. There was no correlation with serotype. DNA type 1 was the commonest overall (22/105 strains, 22%), predominating in serotypes 1,2 and 1,2,3 and including the vaccine strains but not the isolates from Germany. CONCLUSIONS: Current infections due to B pertussis are not caused by a clonal pathogen as multiple strains are circulating in a given population at one time. There is also considerable epidemiological variation in the pathogen population between countries. These findings may have implications for the design of acellular vaccines.

Bordetella pertussis↗
PubMed1992

67Ga-9N3 uptake by xenografts of human melanotic melanoma in mice.

Tumour uptake of the inert, neutral complex 67Ga-9N3 and the tumour:blood concentration ratio (1,4,7,triazacyclononane-1,4,7, triacetic acid) were measured in mice bearing xenografts of the human melanotic melanoma HX118. Between 1 and 4 h after the injection the tumour:blood ratio increased from 3.5 to 21 and the concentration of 67Ga-9N3 in the tumour decreased from 0.43 to 0.13% g-1. During the first 24 h the concentration of 67Ga-9N3 in the tumour exceeded that in all other tissues except the liver and kidneys. The tumour:blood ratio and tissue distribution of 67Ga-9N3 at 4 h were compared with those of four other complexes. The results indicated that of the five complexes 67Ga-9N3 would be the most suitable for tumour imaging at early times after administration. Imaging would not be restricted to gamma emitting 67Ga as there is also the possibility of using the 9N3 ligand to bind 111In for single photon emission computed tomography (SPECT), 68Ga for positron emission tomography (PET) or even stable Ga for direct in vivo nuclear magnetic resonance (NMR) detection.

Animals↗
PubMed1992

The 14th C. L. Oakley Lecture. Candida albicans HSP 90: link between protective and auto immunity.

Heat shock proteins (HSP) are thought to play a role in the aetiology of autoimmune diseases, but are also common targets for the immune response to many infections. Patients recovering from systemic candidosis produce antibodies to Candida albicans HSP 90, both to species-specific epitopes and, more commonly, to epitopes shared with human HSP 90. One such autoreactive antibody was protective in a mouse model of systemic candidosis.

Animals↗
PubMed1992

Clamped homogeneous electric field gel electrophoresis typing of Torulopsis glabrata isolates causing nosocomial infections.

Thirty isolates of Torulopsis glabrata were examined by pulsed-field gel electrophoresis, which resolved 13 DNA pieces, allowing the identification of 12 types. Bands at 1,400, 1,200, 1,070, 1,025, 681, and 500 kbp were conserved. When applied to 18 isolates from an outbreak, 10 distinct types were identified by this technique. Seven patients had isolates which were identical.

Candida↗
PubMed1992

Restriction endonuclease analysis of Aspergillus fumigatus DNA.

AIMS: To develop a genome based DNA fingerprinting system for Aspergillus fumigatus mould. METHODS: DNA was extracted from 21 isolates obtained from eight patients with an aspergilloma. This was with a freeze-dried mycelial extract fragmented in liquid nitrogen. DNA was subsequently purified by phenol-chloroform extraction followed by ultracentrifugation on a caesium chloride gradient. The DNA was restricted by EcoRI and Xba I. RESULTS: All isolates were identical when cut by EcoRI; Xba I delineated six DNA types. CONCLUSIONS: DNA fingerprinting can be used to type isolates of A fumigatus. Strains from within an aspergilloma which were morphologically distinct could either have the identical DNA fingerprint or produce a unique type.

Aspergillosis↗
PubMed1991

Hospital outbreaks with yeasts.

Five previous outbreaks of disseminated candidosis due to Candida albicans are reviewed and a new outbreak on a neonatal unit in Belfast presented. This involved four disseminated cases. The control and definition of outbreaks by morpho-, immunoblot- and DNA-typing is discussed. An outbreak of Torulopsis glabrata infection involving 23 patients is described. This was defined by DNA fingerprinting with the enzyme Xba. There were five deaths attributable either completely or in part to the yeast infection.

Cross Infection↗
PubMed1991

HSP 90, yeasts and Corynebacterium jeikeium.

Recovery from disseminated candidosis is associated with seroconversion to a 47 kDa breakdown product of the Heat Shock Protein (HSP) 90 of Candida albicans. Cloning, sequencing and epitope mapping has allowed the delineation of the immunodominant epitopes LKVIRKNIVKKMIE and STDEPAGESA. Monoclonal and polyclonal antibodies specific to these epitopes are used to show that all strains of C. albicans tested produce HSP 90 in both the yeast and mycelial phases. Homologous proteins are demonstrated in Saccharomyces cerevisiae, Candida parapsilosis and Corynebacterium jeikeium but not in Torulopsis glabrata. Evidence is presented for the existence of two distinct HSP 90s in C. albicans. The first of these is expressed constitutively whilst the second is produced on heat shocking the yeast from 23 to 37 degrees C.

Amino Acid Sequence↗
PubMed1991

Heat shock protein 88 and Aspergillus infection.

Immunoblotting was used to dissect the antibody responses in the sera of 50 patients with proven invasive aspergillosis, 28 patients with suspected invasive aspergillosis, 35 patients with allergic bronchopulmonary aspergillosis, and 10 patients with an aspergilloma. This demonstrated the immunodominance of antigenic bands at 88, 84, 51, and 40 kDa. Monoclonal antibodies against the heat shock protein 90 complexes of Candida albicans and the water mold Achlya ambisexualis identified these four antigenic bands as homologous proteins. Similar antigens have been described in humans, mice, Saccharomyces cerevisiae, chickens, and Drosophila species. The antibody against A. ambisexualis has previously been shown to cross-react with antigens belonging to the human heat shock protein 90 complex. Aspergillus heat shock protein 90 was extracted from the sera of patients with invasive aspergillosis by affinity chromatography. This was done with both a rabbit hyperimmune antiserum raised against an extract of Aspergillus fumigatus NCPF 2109 and a monoclonal antibody against the heat shock protein 90 of C. albicans. In vivo expression of the antigen was demonstrated in an aspergilloma surgically removed from a patient. The role of the antigen as an allergen in allergic bronchopulmonary aspergillosis is also discussed.

Allergens↗
PubMed1991

Autoantibody to heat-shock protein 90 can mediate protection against systemic candidosis.

Epitope mapping shows that patients recovering from systemic infection with Candida albicans produce antibodies against both fungal-specific and conserved epitopes of the heat-shock protein (hsp) 90. In a mouse model of systemic candidosis, mortality was halved by prior administration of sera from two infected patients containing antibodies to hsp 90. One of these patients had no other candidal antibodies detectable on immunoblotting. The protective effect was mediated by the immunoglobulin fraction of the immune serum. It was not observed with a normal human serum. A mouse monoclonal antibody raised against one of the conserved peptide epitopes suggested that an autoantibody to hsp 90 could mediate protection against systemic candidosis in the animal model.

Animals↗
PubMed1990

Characterization of the antibody response in Corynebacterium jeikeium septicaemias.

Corynebacterium jeikeium causes septicaemia in neutropenic patients usually after colonizing intravenous lines. This paper reports the results of immunoblotting sera from 14 patients with a C. jeikeium septicaemia. Recovery from the septicaemia was associated with production of both IgM and IgG against antigenic bands of 50, 52 and 110 kDa. Antibody against the 110 kDa band was present in controls but the antibody against the 50 and 52 kDa was specific to those patients who had on-going or previous C. jeikeium infection. A case of C. jeikeium endocarditis is also presented and here recovery was associated with seroconversion to the 50 and 52 kDa bands.

Antibodies, Bacterial↗
PubMed1989

Immunoblot fingerprinting Aspergillus fumigatus.

A new technique for typing Aspergillus fumigatus is presented. This is based on immunoblot fingerprinting each isolate against a rabbit hyperimmune antiserum raised against A. fumigatus NCTC 2109. All isolates were typable and reproducibility for the 16 antigenic bands which formed the basis of the system was excellent. Discrimination was better than silver staining and revealed 11 types among the 21 isolates from eight patients with an aspergilloma. Each aspergilloma could be due to either a single or multiple types.

Animals↗
PubMed1989

A comparison of immunoblot and DNA restriction patterns in characterising methicillin-resistant isolates of Staphylococcus aureus.

The ability of EcoR1 restriction enzyme fragmentation patterns and of immunoblotting to differentiate methicillin-resistant isolates of Staphylococcus aureus were compared. All isolates examined were typable by both methods and the reproducibility of each was excellent. Immunoblotting differentiated eight types and DNA restriction patterns four. The former technique was of value in characterising methicillin-resistant isolates of S. aureus and controlling an outbreak due to them.

DNA, Bacterial↗