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Biomedical subjects

R G Masterton

Publications and source records attributed to R G Masterton.

At least 19 recordsLinked to original sources
PubMed2002

Investigation into the selection frequency of resistant mutants and the bacterial kill rate by levofloxacin and ciprofloxacin in non-mucoid Pseudomonas aeruginosa isolates from cystic fibrosis patients.

The frequency by which resistant Pseudomonas aeruginosa strains could be selected was compared for two antibiotics, levofloxacin and ciprofloxacin. Seven distinct strains were cultured on plates containing 1x, 2x, 4x and 8x the minimum inhibitory concentration (MIC) of the antibiotic under investigation. Resistant mutants were more readily isolated by growth on culture plates that contained ciprofloxacin, and the resulting MIC of the resistant mutant was also more frequently increased. Time-kill studies on comparable strains where the MIC for both antibiotics had increased by at least fourfold showed no difference between the two agents.

Adult↗
PubMed2001

Randomized, double-blind study comparing 5- and 7-day regimens of oral levofloxacin in patients with acute exacerbation of chronic bronchitis.

A randomized, double-blind, multicentre study was conducted in adult patients with acute exacerbation of chronic bronchitis (AECB), to compare the efficacy of a 5-day course of levofloxacin 500 mg once daily, with the standard 7-day regimen at the same dose. Five hundred and thirty-two patients from 48 centres in 10 countries were randomized to receive levofloxacin: 268 and 264 received the 5- and 7-day courses, respectively. The primary efficacy analysis was the clinical response at 7-10 days post-treatment in the per-protocol (PP) population. Clinical success rates in the primary PP analysis of 482 patients were 82.8% (197/238) for the 5-day group and 84.8% (207/244) for the 7-day group. The difference in success rates was -2.1% with a 95% CI of (-9.1 to 4.9%). The bacteriological response showed eradication rates of 82.1% (92/112) and 83.2% (84/101) in the 5- and 7-day groups, respectively. Both treatments were well tolerated. These results show that for patients with AECB levofloxacin 500 mg once daily for 5 days provides equivalent clinical and bacteriological success to the same dose given for 7 days irrespective of the patient's age, the frequency of exacerbations or the presence of co-existing cardiopulmonary or chronic obstructive airways disease.

Acute Disease↗
PubMed2000

Surveillance studies: how can they help the management of infection?

The increase in antimicrobial resistance has led to predictions of doom in the international press and to depression in the medical community. It has focused attention upon measures for fighting resistance, foremost of which is susceptibility surveillance. Until recently, global efforts at surveillance have been largely uncoordinated and random. This scene is rapidly changing with the World Health Organization (WHO), among others, leading multidisciplinary, targeted initiatives. In terms of individual surveillance programmes, much has been learned about their design. The best of these, the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC), SENTRY and the Alexander Project, involve well-defined patient and organism groups against key denominators, and use standardized, internationally recognized methods that are quality-controlled, explore susceptibility quantitatively and include investigation of resistance mechanisms. Results are rapidly returned to the user. Evidence shows that surveillance, when used to guide policies on antibiotic use and infection control, can be helpful in the fight to control the development and spread of resistance. Further work is required to demonstrate these benefits and quantify them fully.

Anti-Infective Agents↗
PubMed1999

The effect of specimen processing delay on borate urine preservation.

AIM: To investigate the effect on urine culture results and their clinical interpretation of delaying the processing of urine samples in which boric acid had been used as a preservative. METHODS: 792 mid-stream specimens of urine from patients attending their general practitioner were received in borate containing plastic jars. The specimens were cultured upon receipt, stored at room temperature, and then recultured the following morning. RESULTS: After overnight delayed culture, the results were altered in 16% of samples and the clinical interpretation of these findings differed in 8% of specimens. In 28 samples (3.5%) the bacterium isolated on initial culture was not the same as that obtained by culture after overnight storage. CONCLUSIONS: Boric acid urine preservation used for overnight delayed processing of samples is associated with a significant alteration in culture results and the attendant clinical interpretation of such specimens. Rapid transportation/processing of urine specimens must remain the optimum procedure.

Bacteria↗
PubMed1998

Investigation of infection in the neutropenic patient with fever.

Episodes of infection occurring in neutropenic patients are often associated with high levels of morbidity and mortality and prompt, accurate diagnosis allowing the rapid instigation of appropriate treatment can lead to an improved outcome. Recent developments in laboratory technology have increased the range of investigations available to the physician. The improved sensitivity of traditional microbiological culture, methods for antigen and antibody detection and the advances in molecular biology are among the reasons for an increased ability to detect both familiar and novel pathogens. This article describes the current methods available for determining the aetiology of an infectious episode in these patients. A plan of management for investigation of febrile episodes in neutropenic patients is suggested.

Acute-Phase Proteins↗