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Biomedical subjects

M J Green

Publications and source records attributed to M J Green.

At least 91 records · Page 5Linked to original sources
PubMed1983

Novel 17 alpha-chloro-17 beta-sulfinyl steroids as specific inhibitors of sebaceous gland activity: potential antiacne agents.

The preparation and antisebaceous gland activities of a series of 17 alpha-chloro-17 beta-sulfinyl steroids are described. They were obtained from the corresponding 17 alpha-sulfides by chlorination and oxidation with iodobenzene dichloride in aqueous pyridine at -40 degrees C. A single-crystal X-ray structure determination of 17 alpha-chloro-17 beta-(benzylsulfinyl)-1,4-androstadiene-3,11-dione (4) established the absolute configuration at sulfur to be R. From an analysis of their CD spectra, some of the other alpha-chloro sulfoxides were also assigned the same absolute stereochemistry at sulfur. Inhibition of sebaceous gland activity, after topical application of the test compounds, was determined in hamsters and found to reach a maximum with 4. The 17 beta-sulfone and 17 alpha-sulfide corresponding to 4 were less potent. Subcutaneous administration of 4 produced no antiandrogenic effects in either hamsters or rats.

Acne Vulgaris↗
PubMed1980

Antimicrobial susceptibility of Neisseria meningitidis isolated from 1975-1979.

During the period 1975 to 1979, 88 isolates of Neisseria meningitidis from cerebrospinal fluid (CSF), 28 isolates from blood, and 89 isolates from other sources were serogrouped and tested for their susceptibility to sulphadiazine, penicillin, minocycline and rifampin. Prior to 1979, isolates from CSF or blood were predominantly serogroup B. In the sample tested, the prevalence of this serogroup decreased while the prevalence of serogroup A isolates increased, until in 1979 this was the predominant serogroup. From 1975, the incidence of sulphonamide-resistance in the serogroup B isolates from CSF or blood decreased. However, all serogroup A isolates from these sources, except the first one tested, were sulphonamide-resistant. The 89 isolates from other sources remained predominantly sulphonamide-sensitive serogroup B. All isolates were sensitive to penicillin, minocycline and rifampin.

Anti-Bacterial Agents↗
PubMed1980

Synthesis and structure-activity studies of a series of 7 alpha-halogeno corticosteroids.

The preparation and topical antiinflammatory potencies of a series of 7 alpha-halogeno-16-substituted-prednisolone derivatives are described. The 7 alpha-chloro, 7 alpha-bromo, and 7 alpha-iodo corticosteroids were obtained by addition of hydrogen halide to the 6,7-dehydro compounds. The extent of addition of HCl varied with substitution at C-11, while no addition of HF was observed at all. The 7 alpha-fluoro corticosteroids were prepared by reaction of the appropriate 7 beta-hydroxy compounds with N,N-diethyl(2-chloro-1,1,2-trifluoroethyl)amine. The 7 beta-hydroxy steroids were obtained, in turn, from the 6,7-dehydro compounds via the 6 beta,7 beta-dihydroxy derivatives. Antiinflammatory potencies were measured in mice by the Tonelli croton oil ear assay. The greatest effect of a 7 alpha-halogen was observed in the 16 alpha-methylprednisolone series, where 7 alpha-chloro and 7 alpha-bromo substitution increased potency 2.5- to 3.5-fold. Compounds 4b and 5b were equipotent to betamethasone dipropionate. 7 alpha-Halogen substitution in other series produced more variable effects and sometimes led to a reduction of antiinflammatory potency.

Administration, Topical↗
PubMed1980

The influence of esterification on the topical antiinflammatory activity of 7 alpha-chloro- and 7 alpha-bromo-16 alpha-methylprednisolones.

The effect on topical antiinflammatory potency of altering the ester functions of 7-halogenocorticosteroids was examined. Highest potencies for both 7 alpha-chloro- and 7 alpha-bromo-16 alpha-methylprednisolones were generally achieved through diesterification at the 17- and 21-positions. However, among these diesters, structure seems to be more important for topical potency than lipophilicity.

Administration, Topical↗
PubMed1979

In vitro antimicrobial susceptibility of Streptococcus pneumoniae in New Zealand.

Ninety-seven isolates of Streptococcus pneumoniae referred to the National Health Institute between January 1976 and March 1978 were tested for their susceptibility to 10 antimicrobials. All were susceptible to penicillin, erythromycin, chloramphenicol, vancomycin, clindamycin, cephalothin and rifampicin. Resistance to tetracycline was found in 9.3 percent of the isolates, and 9.7 percent were resistant to a combination of sulphamethoxazole and trimethoprim.

Anti-Bacterial Agents↗
PubMed1979

Characterization of R-plasmids coding for ampicillin resistance from Salmonella species.

A sudden increase in the incidence of ampicillin resistance was observed among Salmonella species isolated within New Zealand in 1973--4. This increase was due mainly to the apperance and proliferation of Salmonella newington and Salmonella anatum serotypes resistant to ampicillin. The plasmid complements of 14 ampicillin-resistant S. newington and S. anatum isolates obtained from widely separated geographical areas within New Zealand between 1973 and 1974 were characterized by agarose gel electrophoresis. Each contained one or more plasmids ranging in molecular weight from 1.4 to 42 Mdal. Eleven isolates contained a self-transmissible plasmid of 33 Mdal which encoded resistance to ampicillin. After transfer to Escherichia coli, the 33 Mdal R-plasmids from each of these isolates were shown to be identical by restriction endonuclease analysis. The remaining three strains contained ampicillin R-plasmids having molecular weights of 35, 37.5 and 42 Mdal. These plasmids were shown by restriction endonuclease analysis to be related to the 33 Mdal R-plasmid. We conclude that the 33 Mdal plasmid and its derivatives were responsible for the increase in the incidence of ampicillin-resistant S. newington and S. anatum serotypes among the total Salmonella population.

Ampicillin↗
PubMed1979

A novel class of potent topical antiinflammatory agents: 17-benzoylated, 7 alpha-halogeno substituted corticosteroids.

As part of continued efforts in the synthesis of structurally novel corticosteroids, a number of 17 alpha-benzoylated, 7 alpha-halogeno substituted prednisolones were tested for topical antiinflammatory activity. 7 alpha-Chloro, 7 alpha-bromo, and 7 alpha-iodo corticosteroids were synthesized by hydrogen halide addition to 1,4,6-triene-3-ones. The 7 alpha-fluoro substituted steroid was obtained by reaction of the appropriate 7 beta-hydroxy compound with N,N-diethyl(2-chloro-1,1,2-trifluoroethyl)amine. Antiinflammatory potencies were obtained using a croton oil-induced inflammation in the ears of mice. In this assay the greatest effect of a 7 alpha-halogen was observed in the 16 alpha-methylprednisolone series, where 7 alpha-fluoro and 7 alpha-bromo substitution yielded corticosteroids with topical potencies significantly higher than those of the corresponding 17,21-dipropionate analogs. Surprisingly, little potency enhancement due to 7 alpha-halogenation was discerned in the 16 beta-methylprednisolone series.

Administration, Topical↗
PubMed1978

In-vitro antimicrobial susceptibility of Neisseria gonorrhoeae in New Zealand.

Four hundred and forty-two isolates of Neisseria gonorrhoeae were tested by an agar dilution method for their susceptibility to penicillin, ampicillin, tetracycline, cephaloridine, and spectinomycin. Of these isolates, 295 were tested for their susceptibility to sulphamethoxazole and to trimethoprim by the same method, using Oxoid diagnostic sensitivity test agar plus 7.5% laked horse blood instead of Proteose No. 3 agar plus 1% IsoVitaleX and 1% haemoglobin. One hundred (22.6%) of the isolates were found to be relatively resistant to penicillin (minimum inhibitory concentration (MIC) less than 0.1 iu/ml), but only 1.1% had a MIC of 1 iu/ml or higher. Ampicillin was slightly more active than penicillin in that all isolates were inhibited by 0.5 microgram/ml or less. For 3.7% of isolates the MIC of tetracycline was 2 microgram/ml or higher. All isolates were sensitive to spectinomycin. By calculating the Spearman rank correlation coefficient (rs), a high correlation (rs greater than 0.5) was found between susceptibility to penicillin and susceptibility to ampicillin, tetracycline, and cephaloridine. Low correlation (rs less than 0.2) was found between susceptibility to penicillin and susceptibility to spectinomycin, sulphamethoxazole, and trimethoprim.

Anti-Bacterial Agents↗