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Biomedical subjects

R S Matthews

Publications and source records attributed to R S Matthews.

At least 19 recordsLinked to original sources
PubMed1998

New cyclooxygenase-2/5-lipoxygenase inhibitors. 1. 7-tert-buty1-2,3-dihydro-3,3-dimethylbenzofuran derivatives as gastrointestinal safe antiinflammatory and analgesic agents: discovery and variation of the 5-keto substituent.

A series of 5-keto-substituted 7-tert-buty1-2,3-dihydro-3,3- dimethylbenzofurans (DHDMBFs) were prepared and evaluated as potential nonsteroidal antiinflammatory and analgesic agents. Interest in this class of compounds arose when a DHDMBF was found to be an active metabolite of the di-tert-butylphenol antiinflammatory agent tebufelone. We have now found that a variety of 5-keto-substituted DHDMBFs have good in vivo antiinflammatory and analgesic activity after oral administration. These compounds inhibit both cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) in vitro. The cyclooxygenase inhibition was found to be selective for the cyclooxygenase-2 isoform, and this combination of COX-2/5-LOX inhibition may be responsible for the gastrointestinal safety of compounds such as 30.

Animals↗
PubMed1995

Artemia salina as a test organism for measuring superoxide-mediated toxicity.

The purpose of this study was to examine the possibility of using Artemia salina as a test organism in the search for compounds having the ability to protect against superoxide-mediated toxicity. The basic procedure for the assay using Artemia salina was performed as described in previous literature, with minor modifications. We found that Artemia salina are extremely sensitive to menadione bisulfite, a compound whose toxicity is probably mediated by intracellular superoxide generation. Desferrioxamine (desferal), a compound with known protective effects, was shown to display dramatic protective activity in our system. We also observed that an inhibitor of endogenous superoxide dismutase (SOD) activity increased the toxicity of menadione toward Artemia salina. In conclusion, this simple, inexpensive, and convenient assay could be a valuable addition to a screening effort in the search for compounds that will be protective against damage by superoxide or other active oxygen species.

Animals↗
PubMed1993

Evaluation of an enzyme-linked immunoassay and confirmatory test for the detection of Chlamydia trachomatis in male urine samples.

First pass urine (FPU) samples were compared with urethral swab culture from 304 males attending a genitourinary medicine clinic using an enzyme immuno assay (EIA). All of the EIA positive samples were retested by incorporating a novel blocking reagent into the EIA protocol; 101 were positive by culture of which 83 were also positive by FPU EIA, an additional four were detected in FPU only and not by culture; 86 of these 87 were also confirmed positive by the blocking reagent. Discrepant results were evaluated by Syva MicroTrak. The sensitivity and specificity of FPU EIA as compared with urethral swab culture was 82.2% (83/101) and 98% (199/203) respectively with positive and negative predictive values of 95.4% (83/87) and 91.7% (199/217). Male urethral swab culture is more sensitive than FPU EIA; however, when culture is not available then FPU offers a reliable non-invasive alternative to swab EIA which may be of enormous benefit in community screening of asymptomatic as well as symptomatic patients.

Antibodies↗
PubMed1991

In-vitro susceptibility of Chlamydia pneumoniae (TWAR) to seven antibiotics.

A modification of an immunofluorescence method previously used to study the in-vitro antimicrobial susceptibilities of Chlamydia trachomatis was used to investigate the activity of seven antimicrobials against a strain of C. pneumoniae. Our results differed from those obtained by other workers, so we modified our original method and repeated the study. Adding antimicrobial to pre-infected cells gave higher MICs and MLCs than when cells were infected in the presence of the antimicrobials, and this difference in methodology could account for the discrepancy between our results and those of others. Of the antimicrobials studied, clarithromycin and its 14-hydroxy metabolite were the most active agents; sparfloxacin was more active than ciprofloxacin, but no more active than more conventional antichlamydial agents.

Anti-Bacterial Agents↗
PubMed1990

In-vitro activity of sparfloxacin, a new quinolone antimicrobial agent.

The in-vitro activity of sparfloxacin (AT-4140), a new difluorinated quinolone, was compared with those of ciprofloxacin, temafloxacin and selected members of other groups of antimicrobial agents, against 651 recent distinct clinical isolates and strains with known mechanisms of resistance. Three strains of Chlamydia trachomatis were also studied. The MICs for 90% of the Enterobacteriaceae were between 0.06 and 1 mg/l; for Pseudomonas aeruginosa the MIC90 was 2 mg/l. Sparfloxacin was 16-fold more active against Acinetobacter spp. than ciprofloxacin. For Staphylococcus spp., Streptococcus, spp. and Enterococcus faecalis the MIC90 was between 0.25 and 1 mg/l; sparfloxacin was four-fold more active against Str. pneumoniae than ciprofloxacin. Ninety percent of strains of Haemophilus influenzae, Branhamella catarrhalis and Neisseria spp. were inhibited by less than 0.03 mg/l; for Bacteroides fragilis the MIC90 was 1 mg/l. The three strains of Chl. trachomatis were susceptible to 0.06-0.12 mg/l sparfloxacin, which was 16-fold more active than ciprofloxacin. There was cross resistance among the quinolones, but not between the quinolones and other groups of antimicrobials. The protein binding of sparfloxacin was 40% and serum had little effect on its activity.

Anti-Bacterial Agents↗
PubMed1990

Evaluation of a novel solid-phase immunoassay, Clearview Chlamydia, for the rapid detection of Chlamydia trachomatis.

Clearview Chlamydia (Unipath Limited, Bedford, United Kingdom) is a rapid immunoassay for the direct detection of Chlamydia trachomatis antigen. This assay was evaluated against the tissue culture method by using 376 paired endocervical specimens. The Clearview assay had a sensitivity of 93.5% and a specificity of 99% when it was compared with the tissue culture method. This assay does not require specialized equipment or trained personnel and yields results within 30 min from the time that a specimen is collected.

Bacteriological Techniques↗
PubMed1988

In vitro activity of lomefloxacin, a new quinolone antimicrobial agent, in comparison with those of other agents.

The in vitro activity of lomefloxacin (SC-47111; NY-198), a new difluorinated quinolone, was compared with those of ofloxacin, ciprofloxacin, fleroxacin, amoxicillin, cefuroxime, and trimethoprim against 585 recent clinical isolates and other strains with known mechanisms of resistance. The MICs of lomefloxacin against 90% of the members of the family Enterobacteriaceae, Pseudomonas aeruginosa, and staphylococci were between 0.25 and 4 micrograms/ml. Ninety percent of Neisseria sp. and Haemophilus influenzae were susceptible to less than or equal to 0.06 micrograms/ml, and streptococci (including Streptococcus pyogenes, Streptococcus pneumoniae, and enterococci) and Bacteroides fragilis were susceptible to 8 micrograms/ml. Lomefloxacin was comparable in activity to fleroxacin and ofloxacin, but it was less active than ciprofloxacin. There was cross-resistance between the quinolone group of antimicrobial agents. The protein binding of lomefloxacin was 15.4%, and serum had little effect on the activity of the compound. However, urine at pH 5.0 decreased the activity by two- to eightfold compared with that at pH 7.0

Amoxicillin↗
PubMed1987

Neonatal herpes.

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Cervix Uteri↗
PubMed1987

Commercially available fluorescein-conjugated monoclonal antibody for determining the in vitro activity of antimicrobial agents against Chlamydia trachomatis.

A simple, reproducible method for determining the antibiotic susceptibility of chlamydial isolates is described. Minimum inhibitory and lethal concentrations (MICs and MLCs) were determined for tetracycline and erythromycin titrated against a recent clinical isolate of Chlamydia trachomatis in McCoy cell cultures. A fluorescent antibody stain was found to be more sensitive than giemsa staining, generally giving two-fold higher values for both MICs and MLCs.

Antibodies, Monoclonal↗
PubMed1987

Pooled specimens for Chlamydia trachomatis: new approach to increase yield and cost efficiency.

Pooled specimens from the urethra and cervix accounted for 97% of 101 positive chlamydial isolations in 332 women, and this yield compared favourably with the individual yield from either the urethra (77%) or the cervix (88%). Pooling specimens caused no apparent increase in toxicity to the cell culture system. These results indicate the advantages, in terms of higher yield and no higher cost, of combining the urethral and cervical specimens in one container.

Cervix Uteri↗
PubMed1979

Virus-specific and anticellular antibodies in molluscum contagiosum.

Sera from patients with molluscum contagiosum showed a higher incidence of anticellular and fibrillar anticellular antibodies of IgM class as compared to sera from control subjects. Most patients with anticellular IgM antibodies also had molluscum contagiosum virus-specific antibodies. In a comparative study, there was a higher incidence of anticellular IgM antibodies to normal human epidermis and fibrillar anticellular IgM antibodies in molluscum contagiosum than in warts of psoriasis. The incidence in psoriasis was lower than warts and was similar to that found in control subjects.

Adolescent↗