Mortality among male anaesthetists in the United Kingdom, 1957-83.

A cohort of 3769 male anaesthetists resident in the United Kingdom between 1957 and 1983 was followed up for a total of 51,431 person years of observation. All subjects were fellows of the Faculty of Anaesthetists and held full registration with the General Medical Council. With all men in social class I being taken as the standard, the standardised mortality ratio among anaesthetists for all causes of death was 68 (95% confidence interval 59 to 77) and the standardised mortality ratio for all cancers was 50 (95% confidence interval 36 to 67). There was no significant excess mortality from lymphomas or leukaemias, but 16 of the 221 deaths in anaesthetists were due to suicide, giving a standardised mortality ratio of 202 (95% confidence interval 115 to 328). When anaesthetists were compared with all doctors the standardised mortality ratio for suicide was only 114, a nonsignificant excess. These findings confirm that the risk of suicide among anaesthetists is twice as high as among other men in social class I but suggest that the risk does not differ significantly from that among doctors as a whole. There was no evidence of a significant excess risk of cancer, and, in particular, the small excess of cancer of the pancreas reported previously could not be confirmed.     

Placebo controlled trial of nicotine chewing gum in general practice.

Of 2110 adult cigarette smokers originally recruited to a study of the effect of antismoking advice in general practice, 429 who reported at follow up after one year that they had tried unsuccessfully to stop smoking were offered "a special antismoking chewing gum," either nicotine gum or a placebo gum, in a double blind study. Of 200 who were willing to try the gum, 101 were randomly allocated to the nicotine gum and 99 to the placebo gum. They were followed up at six months by an unannounced home visit, at which they were interviewed and asked to provide a breath sample for analysis of carbon monoxide. Twenty five claimed that they had stopped smoking, but, of them, seven exhaled levels of carbon monoxide indicative of continued smoking. Of the 18 in whom giving up smoking was validated, 10 had received active gum and eight placebo gum, a difference which was not significant (odds in favour of nicotine gum = 1.25, 95% confidence limits 0.47-3.31). The value of nicotine chewing gum, if any, can be quite small when it is used in general practice.     

The biochemical basis for the conjugation of bile acids with either glycine or taurine

All animals, except for the placental mammals, conjugate their bile acids exclusively with taurine. However, in certain of the placental mammals, glycine conjugates are also found. The basis for the appearance of glycine conjugation among the placental mammals was investigated. The reaction of choloyl-CoA with glycine and taurine, as catalysed by the soluble fraction from guinea-pig liver, had a high affinity for taurine and a poor affinity for glycine. The predominant synthesis of glycine conjugates in the guinea pig can be related to the fact that guinea-pig liver contains an unusually low concentration of taurine and a high concentration of glycine. Rabbits make exclusively glycine conjugates and their livers also contain low concentrations of taurine. However, the biochemical basis for their glycine conjugation is more straightforward than in the guinea pig in that the soluble fraction from rabbit liver has a high affinity for glycine and a poor affinity for taurine. Alternative-substrate-inhibition studies with glycine and taurine in soluble fractions from guinea-pig and rabbit liver revealed that glycine and taurine were mutually inhibitory. This suggests that there is only one enzyme for glycine and taurine conjugation in these tissues. The soluble fractions from bovine liver and human liver also made both glycine and taurine conjugates and evidence is presented that suggests that there is only one enzyme in these tissues too. Even the rat, which excretes mostly taurine conjugates, could make both glycine and taurine conjugates in vitro. However, in contrast with all of the placental mammals studied, the supernatant fraction from liver of the chicken, and other non-mammals, could not make glycine conjugates even in the presence of very high concentrations of glycine.     

Breast cancer and oral contraceptives: findings in Oxford-Family Planning Association contraceptive study.

Among the 17 032 women taking part in the Oxford-Family Planning Association contraceptive study, 72 were first diagnosed as having breast cancer between the date they were admitted to the study and 1 September 1980. The relative risk of developing the disease in women who had used oral contraceptives in comparison with those who had never used them was estimated to be 0.96 (95% confidence limits 0.59 to 1.63). Among women aged under 35 years, the corresponding relative risk (based on only 14 women with breast cancer) was estimated to be 0.61. No relation was apparent between the risk of developing breast cancer and duration of oral-contraceptive use or interval since first oral-contraceptive use in any age group. The data in this study are thus reassuring; but observations based on women with long-term use of oral contraceptives, especially those starting to use the preparations at an early age, are few.     

Pelvic inflammatory disease and the intrauterine device: findings in a large cohort study.

The incidence of pelvic inflammatory disease was investigated among parous women taking part in the Oxford-Family Planning Association contraceptive study. Hospital admission rates for "acute definite" disease were 1.51 per 1000 woman-years among those currently using an intrauterine device (IUD) and 0.14 per 1000 woman-years among those using other methods of birth control (age-standardised relative risk 10.5 to 1 with 95% confidence limits of 5.4 to 1 and 32 to 1). There was little evidence of an increased risk of such disease in ex-users of an IUD. Hospital admission for "chronic definite" disease, on the other hand, was commoner in ex-users of an IUD than in current users. Acute definite disease occurred somewhat more frequently during the early months of use of an IUD than during the later months. While the rate of such disease was increased in users of each type of device, the highest rate (8.1 per 1000 woman-years) was observed in users of the Dalkon shield. This rate, however, was based on only three affected women.     

Genetics of 51d-52a, a Region Containing Several Maternal-Effect Genes and Two Maternal-Specific Transcripts in Drosophila

Two genomic clones exhibiting a maternal-specific pattern of expression map to cytological region 52A. To elucidate the function of these clones we have undertaken a mutagenesis of the cytological region 51D-52A. This paper presents the results of this screen and the preliminary analysis of female-sterile and lethal mutations isolated. A total of twelve complementation groups have been identified, four of which are defined exclusively by female-sterile alleles. Only one visible mutation was isolated, a recessive temperature-sensitive allele of Thickened-arista (Tarts). Several of the seven lethal loci display an embryonic lethal phase. Three of the four female-sterile loci affect chorion structure with one resulting in underamplification of the chorion genes, and two (possibly three) of the four female-steriles affect nuclear division/DNA replication. Thus it appears that this is a "developmentally important" region, possibly representing a clustering of genes involved in either DNA replication or nuclear division.