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Biomedical subjects

J Gedney

Publications and source records attributed to J Gedney.

7 recordsLinked to original sources
PubMed1987

Chromosomal resistance of gonococci to antibiotics.

Three hundred and twenty nine strains of non-penicillinase-producing Neisseria gonorrhoeae (non-PPNG) isolated from men and women were tested for their susceptibility to a range of antibiotics, and were also auxotyped and serogrouped. Nearly 6% (18) of 312 strains tested were resistant to 1 mg/l or more penicillin (compared with 4.4% of PPNG strains isolated in 1981). Many (198, 64%) strains showed intermediate resistance to penicillin (0.12-0.5 mg/l). Nearly 5% (15) of 312 strains tested were resistant to 0.5 mg/l or more cefuroxime, and there was a high degree of cross resistance between these two antibiotics. High levels of resistance to erythromycin and tetracycline were also found, and there was also appreciable cross resistance between these antibiotics and the beta lactam drugs. Resistance to spectinomycin was rare, and there was no cross resistance between spectinomycin and other agents tested. Levels of resistance between strains isolated from different anatomical sites did not differ, except that resistance to erythromycin was greater in rectal isolates. Four main auxotypes were detected. Strains requiring arginine, hypoxanthine, and uracil (AHU-) were more prevalent from the cervix. We have shown that there is an association between auxotype, serogroup, and level of sensitivity to penicillin, cefuroxime, and tetracycline.

Anti-Bacterial Agents↗
PubMed1986

Penicillinase producing gonococci: a spent force?

Though the incidence of gonorrhoea caused by penicillinase producing Neisseria gonorrhoeae (PPNG) strains at St Mary's Hospital rose rapidly from 1980 to reach 6.2% in 1982, it declined in 1983 (8.6%) and in 1984 (6.5%), a trend that has continued in 1985. The use of penicillinase stable antibiotics or more effective contact tracing are unlikely to be responsible for this recent decline. We have always isolated very few PPNG strains from homosexual men, and the possible effects of the acquired immune deficiency syndrome (AIDS) on sexual behaviour in this group is therefore unlikely to be relevant. We have seen a steady increase in the proportion of PPNG strains carrying the 4.4 megadalton penicillinase plasmid (67% of PPNG strains in 1984). Strains carrying both the 4.4 megadalton plasmid and the 24.5 megadalton conjugal plasmid were very common in 1982, but since then have declined in importance. PPNG strains carrying the 3.2 megadalton plasmid have become less common, and the presence of the 24.5 megadalton plasmid in these strains has not apparently led to their wider dissemination in the community. Whereas the basic pattern of PPNG auxotypes has changed little, since 1982 we have isolated an increasing number of mixed auxotypes with nutritional requirements other than just proline. PPNG strains carrying the 4.4 megadalton plasmid seem to be more resistant to erythromycin, tetracycline, and streptomycin than those carrying the 3.2 megadalton plasmid. Spectinomycin resistance has only occurred in strains carrying the 4.4 megadalton plasmid.

Gonorrhea↗
PubMed1986

Nipple differentiation in fetal male rats treated with an inhibitor of the enzyme 5 alpha-reductase: definition of a selective role for dihydrotestosterone.

In the rat, androgens are responsible for sexually dimorphic nipple differentiation. Nipples are expressed in the female, while in the male, the nipple anlage regress prenatally. Mammary gland development is present in both sexes. Treatment of pregnant Sprague-Dawley rats from days 12-21 of gestation with the aza-steroid 17 beta-N,N-diisopropylcarbamoyl-4-aza-5 alpha-androstan-3-one, a competitive inhibitor of the enzyme 5 alpha-reductase, resulted in nipple development in male offspring. Additionally, there was feminization of the external genitalia, with urethral displacement to the base of the phallus. The role of androgens in suppression of nipple anlage in the male rat fetus is known. This study, however, suggests for the first time a selective role for 5 alpha-dihydrotestosterone in regression of the nipple anlage in utero. Thus, 5 alpha-dihydrotestosterone may be critical not only for masculinization of the external genitalia, but also for inhibition of nipple development in the male rat fetus.

5-alpha Reductase Inhibitors↗
PubMed1985

Evaluation of a direct immunofluorescence test for diagnosing gonorrhoea.

A new direct immunofluorescence reagent (Syva and Genetic Systems Inc) was evaluated for its ability to detect Neisseria gonorrhoeae in specimens from populations with a high prevalence of the infection. Gonorrhoea was diagnosed by culture in 45 of 105 (43%) urethral specimens from men and 17 of 90 (28%) urethral and 25 of 60 (42%) cervical specimens from women. In men the immunofluorescence test had a sensitivity of 84.4% and a specificity of 100%; Gram staining gave values of 94% and 100%, respectively. The sensitivity of the immunofluorescence test could be increased to 89% by testing duplicate smears. In women the immunofluorescence test had a sensitivity of 65% and a specificity of 98% for urethral samples and values of 72% and 94%, respectively for cervical samples. At both sites the sensitivity of the Gram stain was 40% and the specificity 100%. The testing of duplicate immunofluorescence smears increased the sensitivity to 76% for urethral and 88% for cervical samples.

Cervix Uteri↗
PubMed1982

Properties of methicillin-resistant staphylococci now endemic in Australia.

Seventy-eight cultures of multiresistant Staphylococcus aureus (MRSA), obtained from Australian hospitals in 1981, were studied to see whether they possessed novel properties responsible for their epidemic spread. In general, these strains resembled MRSA from other countries and were probably derived from them; in particular, they did not survive desiccation better than other staphylococci. The majority of MRSA produced lipases, which might be responsible for their invasiveness, and all produced high amounts of beta-lactamase which hydrolysed each of the isoxazolyl penicillins. This may account for therapeutic failure with cloxacillin of flucloxacillin. Control of this epidemic should rely principally on general measures against the hospital staphylococcus.

Australia↗