PubMed Health⌕ Search

Biomedical subjects

S C Clarke

Publications and source records attributed to S C Clarke.

At least 55 records · Page 3Linked to original sources
PubMed2001

Confirmation of meningococcal disease by urinary antigen testing.

The meningococcus is an important cause of morbidity and mortality and a rapid laboratory diagnosis is required through accurate, non-culture-based methods. Body fluids that are easily obtainable are preferred for this route of diagnosis and urine is the specimen of choice as it can be obtained non-invasively. Urine samples were tested from patients with suspected meningococcal disease and tested by latex agglutination and PCR. It was shown that urinary PCR is not useful for the laboratory confirmation of MD but latex agglutination testing may be useful in certain settings prior to confirmatory testing by a reference laboratory.

Antigens, Bacterial↗
PubMed2001

Laser revascularisation.

Patients who present with angina pectoris due to underlying coronary artery disease which is not controlled by medical therapy, and who have disease which is not amenable to conventional forms of revascularisation, present an increasing clinical problem. Laser techniques have been introduced to improve myocardial perfusion in this group of patients. The surgical technique of transmyocardial laser revascularisation has been evaluated in this patient population. Generally, there has been a good symptomatic response in terms of improvement in angina, and in some studies an increase in exercise capacity. The technique, however, does carry significant morbidity and mortality. More recently, a catheter-based technique has been introduced--percutaneous myocardial laser revascularisation. This technique seems to improve symptoms of angina, produce an increase in exercise capacity, with a much more favourable procedural risk profile.

Angina Pectoris↗
PubMed2001

Automation of fluorescence-based PCR for confirmation of meningococcal disease.

A fluorescence-based PCR method was developed, fully automated, and used to confirm infection with Neisseria meningitidis by detection of the meningococcus-specific ctrA gene. The method provided a highly sensitive, high-throughput assay that was reproducible and less labor-intensive than manual methods.

Bacterial Proteins↗
PubMed2001

Semiautomation of multilocus sequence typing for the characterization of clinical isolates of Neisseria meningitidis.

The Scottish Meningococcus and Pneumococcus Reference Laboratory (SMPRL) provides a national service for the laboratory confirmation of meningococcal and pneumococcal disease in Scotland. Part of this service includes the serogrouping of meningococcal isolates followed by typing and subtyping. The procedures for this are labor-intensive but important for the identification of linked cases and the surveillance of disease so that effective public health measures can be taken. However, different strains of meningococci, such as those within the electrophoretic type 37 complex, occurring during case clusters of disease are now indistinguishable by current methods. The SMPRL has started using multilocus sequence typing (MLST) as a routine method for the characterization of isolates of Neisseria meningitidis. MLST produces nucleotide sequence data of seven housekeeping genes providing results that are useful for public health management. However, the method is laborious and time-consuming and therefore lends itself towards automation. The SMPRL therefore developed a semiautomated method for MLST using a 96-well format liquid handler and an automated DNA sequencer. Semiautomated MLST is now provided as a reference service for Scotland. This work describes the methodology required for the characterization of N. meningitidis and highlights its usefulness for public health intervention.

Automation↗
PubMed2001

Introduction of an automated service for the laboratory confirmation of meningococcal disease in Scotland.

The Scottish Meningococcus and Pneumococcus Reference Laboratory provides a national service for the laboratory confirmation of meningococcal and pneumococcal disease in Scotland. The main tests used for the laboratory confirmation of meningococcal disease are culture, the polymerase chain reaction (PCR), antibody testing, and more recently DNA sequencing. This paper describes the automation of PCR for the laboratory confirmation of meningococcal disease and the typing of meningococcal isolates using DNA sequencing. Both methods have been automated using a robotic liquid handler and automated DNA sequencer. These methods, along with standard culture phenotyping and antibody testing, provide Scotland with an excellent service for the confirmation of meningococcal disease.

Automation↗
PubMed2001

Laser revascularization in the management of coronary artery disease.

In recent years, laser therapy has been evaluated for the treatment of patients with angina who have coronary artery disease which is not amenable to conventional revascularization techniques. The results of transmyocardial revascularization and percutaneous myocardial revascularization are reviewed.

Angina Pectoris↗
PubMed2001

Meningococcal disease due to serogroup Y in Scotland, 1992-1999.

Meningococcal disease is an important cause of morbidity and mortality. A retrospective analysis was performed of all cases of invasive group-Y disease that were laboratory-confirmed in Scotland between 1992 and 1999. A total of 1881 meningococcal isolates were characterised, 78 of which were serogroup Y. The incidence of non-invasive group-Y disease remained level between 1992 and 1999. Only 12 isolates were from invasive disease, comprising five strain types. Invasive group-Y disease was associated mostly with the young or old. Serogroup-Y meningococcal disease was uncommon and a rare cause of invasive disease in Scotland between 1992 and 1999; however, it is essential that microbiologists are aware of its potential for increasing in incidence due to the recent introduction of the MenC vaccine, and its increased incidence in the USA.

Adult↗
PubMed2001

Acid-fast bodies in faecal smears stained by the modified Ziehl-Neelsen technique.

The modified Ziehl-Neelsen (ZN) stain has proved useful in the laboratory diagnosis of cryptosporidiosis and, more recently, for the laboratory diagnosis of cyclospora. Apart from cryptosporidia and cyclospora, many other organisms and artefacts are present in faeces, and may be seen in faecal smears stained by the modified ZN method. Described here is the presence of such organisms and artefacts in faecal samples submitted to the routine microbiology laboratory of a district general hospital. Over 6000 faecal smears were examined using the modified ZN method, with an incidence of cyclospora and cryptosporidium of approximately 0.1% and 1%, respectively. Other organisms and artefacts were observed, with an incidence ranging from 0.1% to 1%. It is emphasised that the identification of known gastrointestinal tract pathogens should not rely solely on the results of their staining reactions. It is essential that criteria such as morphology and size be taken into account to differentiate organisms with similar staining reactions.

Animals↗
PubMed2001

Automated non-culture-based sequence typing of meningococci from body fluids.

In recent years, the polymerase chain reaction has been used for the non-culture diagnosis of meningococcal disease, and sequence-based typing takes this further by providing the full characterisation normally only available by culture. In this study, porA gene sequencing was used to perform non-culture-based sequence typing of Neisseria meningitidis strains direct from body fluids. Non-culture porA gene sequencing provided the serosubtype of the infecting organism, and proved to be a useful method as N. meningitidis was not isolated from any of the patients in this study. In conclusion, porA gene sequencing is a very useful tool for the non-culture characterisation of meningococci and provides important information for public health management of cases and contacts.

Bacterial Typing Techniques↗
PubMed2001

Pneumococcal disease and asplenia: the importance of vaccination.

Pneumococcal disease is an important cause of morbidity and mortality, particularly in certain patient groups including those who have been splenectomised or have no functioning spleen. Recent deaths in two asplenic patients from pneumococcal disease should remind doctors of the importance of vaccination in asplenic individuals. The current guidelines for vaccination in such patients are highlighted and discussed. The need for a national asplenic register is also suggested.

Adult↗
PubMed2000

Development of a risk assessment methodology for evaluating potential impacts associated with contaminated mud disposal in the marine environment.

In order to assess impacts associated with disposal of contaminated mud arising from Hong Kong's dredging and reclamation projects, a methodology has been formulated to determine the level of risk posed by consumption of seafood/marine prey species to humans and to the Chinese White Dolphin (Sousa chinensis). This methodology improves on previously used techniques by incorporating risks for organic contaminants, accounting for doses from sources other than seafood, and incorporating additional local knowledge on Sousa chinensis behaviour. It thus represents an advance in risk assessment techniques and a new integration of risk assessment and monitoring in environmental management.

Animals↗
PubMed1998

Tyrosine phosphorylation in Escherichia coli.

The phosphorylation on tyrosine of a protein in Escherichia coli both in vivo and in vitro was revealed by recognition by anti-phosphotyrosine antibodies, labelling with [gamma-32P]ATP, and phosphoamino acid analysis. This protein, which we name TypA, is the product of the o591 reading frame as revealed by N-terminal sequencing and antibody cross-reactivity. Inactivation of typA altered the patterns of protein synthesis during both exponential growth and carbon starvation. These alterations included the disappearance of an acidic isoform of both the universal stress protein UspA and carbon starvation protein Csp15, and increased synthesis of the histone-like protein H-NS. The sequence of TypA from strain K-12 differs from that of an enteropathogenic strain in six amino acid residues and the protein is three residues shorter. We propose that TypA interacts with global regulatory networks and that its phosphorylation may be relevant to pathogenesis.

Adenosine Triphosphate↗