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Biomedical subjects

C Wray

Publications and source records attributed to C Wray.

At least 145 records · Page 8Linked to original sources
PubMed1971

Blood clotting and platelet aggregation during oral progestogen contraception: a follow-up study.

A two-year follow-up study of progestogen-only contraception with chlormadinone acetate indicates no increase of the level of factors VII and X, as found after three cycles with all oestrogen-progestogen oral contraceptives. Clotting factors which were raised with combined preparations became normal after the sixth monthly cycle of progestogen and remained normal during the two-year period of study.From 12 months onwards significant changes in the thromboelastograph pattern were recorded, but not to the same extent as with combined preparations. At two years platelet aggregation was significantly accelerated with chlormadinone acetate but was not as rapid as with combined preparations.

Blood Coagulation Tests↗
PubMedDate not supplied

A biotyping scheme for Salmonella livingstone.

Salmonella livingstone is one of the more common salmonella serotypes isolated in the United Kingdom. The characterization of 70 different isolates of S. livingstone using biochemical tests and plasmid profile analysis is described. The isolates could be divided into four groups by their ability to grow in d-tartrate, l-tartrate and Stern's glycerol. Further subdivision was achieved by the use of plasmid profile analysis; 24 of the isolates possessed light plasmids (less than 9.5 MD) and four possessed heavy plasmids (greater than 30 MD). The combination of biotyping and plasmid profile analysis can be used as the basis of a scheme to 'fingerprint' S. livingstone for epidemiological studies.

Animals↗
PubMedDate not supplied

Feeding antibiotic-contaminated waste milk to calves--effects on physical performance and antibiotic sensitivity of gut flora.

The effect of feeding calves antibiotic-containing waste milk was studied in two trials. In the first trial both fermented and unfermented waste milk were fed and in the second trial only unfermented milk was used. The antibiotic-containing milk had a poor palatability and rejection rates were high. Growth rates of the calves were poor and in the second trial differed significantly from those of the control calves which had received milk substitute. Faecal E. coli were monitored for antibiotic resistance. In the first trial, the geometric mean minimal inhibitory concentration for streptomycin was significantly higher for isolations from calves fed antibiotic-containing milk, but no differences were observed for ampicillin. In the second trial, the percentage of resistant E. coli and enterococci was determined but no differences were observed between isolations from calves fed antibiotic-containing milk and the controls. The ambient conditions in the United Kingdom did not encourage the rapid natural fermentation, which would degrade the antibiotics and make it an acceptable food, and it was concluded that the high numbers of bacteria in the product may present disease risk.

Animal Feed↗
PubMedDate not supplied

A survey of antimicrobial resistance in Salmonellae isolated from animals in England and Wales during 1984-1987.

Resistance to 14 antimicrobial substances was tested in 18,647 salmonella strains isolated from animals, their environment and from animal feeds during the period 1984-1987. Of the 2284 Salmonella dublin strains the percentage sensitive to all the antimicrobial substances ranged from 18.1 to 26.8. Resistance to the higher concentration of streptomycin (S25) ranged from 1.9 to 6.4%, whereas the corresponding figures when the lower concentration (S10) was used were 32.3 and 63.8%. Resistance to the higher sulphonamide concentration (Su500) never exceeded 3.3%, although in 1987 70.3% of strains showed resistance to the lower concentration. In general, less than 1% of strains showed resistance to the other antibacterial substances. No strains resistant to amikacin (AK), apramycin (Apr), gentamicin (CN) and colistin (CT) were detected. Of the 8677 S. typhimurium strains the percentage sensitive to all the antimicrobial agents ranged from 6.6 in 1985 to 13.6 in 1987. Resistance to tetracycline (T), ampicillin (PN), trimethoprim (TM) and chloramphenicol (C) ranged from 36.5 to 58.8%, the highest percentages being detected with tetracyclines. Less than 1% of strains showed resistance to furazolidone and none was resistant to amikacin and colistin. Resistance to apramycin ranged from 3.1% in 1984 to 11.6% in 1985; the figures for gentamicin were approximately half that of apramycin. In 1984, 41.6% of strains showed resistance to neomycin but only 8.5% in 1987. The fall in neomycin resistance was associated with the epidemic spread of the commonest phage-type DT204C becoming sensitive to neomycin. Of the 7687 strains of serotypes other than S. typhimurium and S. dublin the percentage sensitive to all antimicrobial agents ranged from 23.7 in 1985 to 14.7 in 1987. Resistance to tetracyclines and sulphonamides (Su500) ranged from 5.2 to 12.1% and 5.8 to 13.3% respectively. Resistance to the other antimicrobial agents was usually less than 5%.

Animal Feed↗