Of 6052 adult patients who consulted their doctors in six Oxfordshire general practices between October 1980 and February 1981, 2110 (35%) were smokers. The smokers were allocated to one of four study groups--a control (non-intervention) group; a group that received verbal and written antismoking advice from the general practitioner; a group that received this advice and also a demonstration of exhaled carbon monoxide; and a group that received the advice plus the offer of further help from a health visitor. After one year 72% of smokers replied to a postal follow up questionnaire: 11% of the control group claimed to have stopped smoking compared with 15% in the group that received advice alone, 17% in the exhaled carbon monoxide group, and 13% in the health visitor group. Validation of these findings by assays of urinary concentrations of cotinine showed that between 24% and 40% of subjects may have misreported their smoking habits, but there was no indication that the rate of misreporting was higher in the intervention groups than in the control group. Giving advice routinely against smoking has a useful effect, and showing an immediate, personal, and potentially harmful consequence of smoking using a CO-oximeter may improve this, particularly in lower socioeconomic groups.
New Zealand White rabbits immunized with covalent conjugates prepared from polylysine and the O-carboxy-methyloxime derivatives of either aflatoxin B1 (AFB1) or an analogue, 5,7-dimethoxycyclopentenon (2,3-c) coumarin, produced antibodies that bind 3H-AFB1. The specificities of the antisera with respect to aflatoxins BI, B2a, G1, G2, Q1, P1, and some other structually related compounds were determined. Radioimmunoassays that can detect levels as low as 0.27 pmoles (0.06 ng) of AFB1-were used to analyze serum, urine, and crude extracts of corn and peanut supplemented with aflatoxin. In the foodstuffs, as little as 1 mug AFB1/kg was measured. The immunoassay was at least as sensitive and specific as other available analytic methods, but did not require the purification of samples by chromatography before analysis. The technique may be particularly useful in epidemiologic studies designed to study the possible relationship between chronic aflatoxin ingestion and cancer.
Pepsinogens A, D, and C have been isolated from the gastric mucosae of chickens using ion-exchange and molecular sieve chromatography and were found to have molecular weights of approximately 42,000. Pepsinogens A and D are closely related in their amino acid compositions, electrophoretic mobilities, and stabilities. Pepsinogen C is significantly different in these properties. Unlike swine pepsin, M ultiple forms of pepsinogen, which yield enzymes ~ ~~~ ____ ~ * Publication No. 709 from the Graduate
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