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Biomedical subjects

R Doll

Publications and source records attributed to R Doll.

At least 145 records · Page 8Linked to original sources
PubMed1987

Estimation of dietary intake of nitrate and nitrite in Great Britain.

A survey was conducted of the dietary intake of nitrate and nitrite of 747 people aged 15-74 yr living in four regions in Britain. The mean intakes from food were estimated to be about 95 mg nitrate and 1.4 mg nitrite. Vegetables contributed over 90% of the nitrate intake and cured meats 65% of the nitrite intake. The contribution from drinking-water was estimated to add a further 13.5 mg, about 12% of total intake, but varied greatly depending upon water nitrate concentration. Residents of Oxford and the South-east had a higher intake of dietary nitrate, due to a greater vegetable consumption, whereas those from North Wales and the North-east had a higher nitrite intake due mainly to a greater consumption of bacon. The consumption of relatively low ascorbic acid/high nitrate vegetables was significantly greater in Oxford and the South-east. Smoking appeared to inhibit the uptake of circulating nitrate into the saliva, especially at higher levels of dietary nitrate intake. The efficiency of reduction of nitrate to nitrite in vivo and the effect of differing rates of this conversion on the relative importance of different dietary items as potential sources of nitrite are discussed.

Adolescent↗
PubMed1987

Early oral contraceptive use and breast cancer: results of another case-control study.

We report the results of a case-control study of oral contraceptive use and breast cancer conducted in London, Oxford and Edinburgh between 1980 and 1984. One thousand one hundred and twenty-five women aged 16-64 years with newly diagnosed breast cancer and a like number of matched controls were interviewed and asked about their past due use of oral contraceptives (OCs). Among women aged 45 years or more at diagnosis there was no evidence of an association between OC use and breast cancer. Among the 351 pairs of women aged under 45 years at diagnosis there was a significantly elevated risk associated with increasing duration of use before first full term pregnancy (relative risk for 4+ years use versus never use = 2.6, 95% confidence limits, 1.3-5.4). Since this result is at variance with the findings in some other studies we have investigated the nature of this association with particular emphasis on possible bias, pill type and a latent effect.

Adolescent↗
PubMed1987

Long term mortality after a single treatment course with X-rays in patients treated for ankylosing spondylitis.

Mortality up to 1 January 1983 has been studied in 14,106 patients with ankylosing spondylitis given a single course of X-ray treatment during 1935-54. For neoplasms other than leukaemia or colon cancer, mortality was 28% greater than that of members of the general population of England and Wales, and this increase is likely to have been a direct consequence of the treatment. The proportional increase reached a maximum of 71% between 10.0 and 12.4 years after irradiation and then declined. There was only a 7% increase in mortality from these tumours more than 25.0 years after irradiation and only for cancer of the oesophagus was the relative risk significantly raised in this period. Neither the magnitude of the relative risk, nor its temporal pattern following treatment, were greatly influenced by the age of the patient at first treatment. For leukaemia there was a threefold increase in mortality that is also likely to have been due to the radiotherapy. The relative risk was at its highest between 2.5 and 4.9 years after the treatment and then declined, but the increase did not disappear completely, and the risk was still nearly twice that of the general population more than 25.0 years after treatment. There was some evidence that the risks of acute myeloid, acute lymphatic, and chronic myeloid leukaemia were all increased, but no evidence of any increase in chronic lymphatic leukaemia. The relative risk appeared to be greatest for acute myeloid leukaemia. For colon cancer, which is associated with spondylitis through a common association with ulcerative colitis, mortality was increased by 30%. For non-neoplastic conditions there was a 51% increase in mortality that was likely to be associated with the disease itself rather than its treatment. The increase was apparent for a wide range of diseases and was not confined to diseases that have been associated clinically with ankylosing spondylitis.

Adolescent↗
PubMed1986

Oral contraceptives and hepatocellular carcinoma.

A series of 26 white women aged under 50 who developed hepatocellular carcinoma in a non-cirrhotic liver were studied for the possible role of oral contraceptives. Eighteen of the women had used the "pill" for a median of eight years. Over 1300 women whose use of the pill had been determined in another study served as controls. Patients and controls were divided into five age and four calendar groups and the relative risks associated with oral contraceptives calculated by multivariate analysis. Short term use of the pill was not associated with an increased risk of tumour development; nevertheless, use for eight years or more was associated with a 4.4-fold increased risk (p less than 0.01). When patients with markers of hepatitis B virus infection were excluded the relative risk was 7.2 (p less than 0.01). In both instances the absolute risk for developing hepatoma remained low.

Adult↗
PubMed1986

Cancer of the liver and the use of oral contraceptives.

A case-control study of the use of oral contraceptives was conducted among women certified as having died from cancer of the liver in the period 1979-82 and in the age range 20-44 years. An age matched group of women who died from other causes, not related to use of oral contraceptives, in the same period were used as controls. Information about use of oral contraceptives was obtained from the general practitioners' notes for both cases and controls. Information was obtained for 30 women with histologically confirmed liver cancer, 19 with hepatocellular carcinoma and 11 with cholangiocarcinoma, and for 147 controls. The results were analysed after adjusting for age at diagnosis and year of birth and showed that use of oral contraceptives was associated with a significantly (p less than 0.05) raised relative risk for hepatocellular carcinoma of 3.8 (95% confidence interval 1.0 to 14.6) and use for eight years or more was associated with a significantly (p less than 0.01) increased relative risk of 20.1 (2.3 to 175.7). There were no apparent increases in risk for cholangiocarcinoma. Despite the small number of cases in this study and the methodological problems in assessing use of oral contraceptives from general practitioners' notes, the results were consistent with other similar studies. Although in the United Kingdom primary liver cancer remains an exceptionally rare disease, especially in young women, further research on the role of oral contraceptives is needed in those countries where it is a much more common disease.

Adenoma, Bile Duct↗
PubMed1986

Human papillomavirus types 16 and 18 in carcinomas of the penis from Brazil.

Human papillomavirus (HPV) type-16 DNA sequences were found in 26/53 (49%) and HPV type-18 in 5/53 (9%) of penile cancers. In only one specimen was HPV18 found on its own. HPV16 sequences were integrated into the host cell chromosomes although some monomeric and oligomeric free forms of DNA were detected in a few tissues. HPV18 was, as far as detectable, free and unintegrated in all tissues tested. HPV16 DNA was also detected in 40% of cases of carcinoma of the cervix in 19 women from the same social groups as the males. The viral DNA in the female cases was a mixture of integrated and free forms. The DNA binding protein (ICSP 11/12) of herpes simplex type 2 (HSV2) was not detected in 10 penile cancers tested with a monoclonal antibody.

Antigens, Viral↗
PubMed1986

Cancer of the cervix uteri and vitamin A.

The concentrations of retinol and beta carotene were measured in serum samples taken from 113 women with cervical cancer, 32 with invasive and 81 with pre-invasive disease, and compared with those from 226 age-matched control women. There was little difference in serum retinol levels between women with cancer of the cervix, at any stage, and the control women, after adjusting for potential confounding factors. Serum beta carotene concentrations were likewise similar in women with invasive disease and the controls. However mean beta carotene levels were significantly reduced in women with pre-invasive disease compared to the controls (221.3 cf. 291.6 micrograms l-1, P less than 0.05). This reduction was more evident amongst women with a diagnosis of carcinoma-in-situ (mean 213.1 micrograms l-1 than amongst those with severe dysplasia (mean 228.7 micrograms l-1. There is a negative trend between beta carotene and risk of pre-invasive disease which is of borderline significance. These data have also been used to investigate the effects of smoking and oral contraceptive usage on the serum levels of retinol and beta carotene. Both habits tend to increase retinol and decrease beta carotene concentrations.

Carcinoma in Situ↗
PubMed1986

Passive smoking.

Explore the source record for details and available documents.

Adult↗
PubMed1986

Mortality of nitrate fertiliser workers.

An epidemiological cohort study was conducted to investigate the mortality patterns among a group of workers engaged in the production of nitrate based fertilisers. This study was designed to test the hypothesis that individuals exposed to high concentrations of nitrates might be at increased risk of developing cancers, particularly gastric cancer. A total of 1327 male workers who had been employed in the production of fertilisers between 1946 and 1981 and who had been occupationally exposed to nitrates for at least one year were followed up until 1 March 1981. In total, 304 deaths were observed in this group and these were compared with expected numbers calculated from mortality rates in the northern region of England, where the factory was located. Analysis was also carried out separately for a subgroup of the cohort who had been heavily exposed to nitrates--that is, working in an environment likely to contain more than 10 mg nitrate/m3 for a year or longer. In neither the entire cohort nor the subgroup was any significant excess observed for all causes of mortality or for mortality from any of five broad categories of cause or from four specific types of cancer. A small excess of lung cancer was noted more than 20 years after first exposure in men heavily exposed for more than 10 years. That men were exposed to high concentrations of nitrate was confirmed by comparing concentrations of nitrates in the saliva of a sample of currently employed men with control men, employed at the same factory but not in fertiliser production. The men exposed to nitrate had substantially raised concentrations of nitrate in their saliva compared with both controls within the industry and with men in the general population and resident nearby. The results of this study therefore weight against the idea that exposure to nitrates in the environment leads to the formation in vivo of material amounts of carcinogens.

Aged↗
PubMed1986

Models for respiratory cancer in nickel refinery workers.

Lung and nasal sinus cancer death rates among employees of a nickel refinery in South Wales were examined from the standpoint of quantifying the relationship between exposure and the risk of these two cancers. Areas in the refinery associated with high risk were identified by using a matched case-control approach, and a simple index of exposure for each man was constructed accordingly based on the duration of time spent in these areas. The dependence of relative risk and absolute excess risk for lung and nasal sinus cancers on age at first employment, calendar period of first employment, time since first employment, and duration of exposure in high-risk areas was then analyzed. The relative risk for nasal sinus cancer increased sharply with increasing age at first exposure but remained roughly constant throughout the period of follow-up, while that for lung cancer was independent of age at first exposure and dropped sharply with increasing time since first employment. The implications and limitations of these analyses are discussed in relation to the multistage theory of carcinogenesis and occupational risk assessment.

Adult↗
PubMed1985

Preventive medicine: the objectives.

The objectives of preventive medicine are to prolong life and to reduce disability. Improvements in the standard of living and in medical treatment and specific measures to reduce the incidence of disease have greatly reduced mortality over the last century. The distribution of deaths by age has altered dramatically and, at current rates, the great majority of deaths will occur at 80-85 years of age. Improvement has continued to the present and is still not slackening. It seems unlikely that many deaths can be postponed much beyond 100 years, but a realistic objective would be to raise the median age of death to about 90 years. This would require a substantial reduction in mortality from three groups of diseases that are now the main cause of life lost under 85 years of age: neoplasms, ischaemic heart disease, and other vascular disease. Watch will also need to be kept on diseases that threaten to become more common, so that we can abort new epidemics. Whether a reduction in age-specific mortality rates will also bring a reduction in the prevalence of disability at each age is unclear. Some believe that it will, so that if we concentrate on reducing age-specific mortality, everyone will eventually survive to such an age that failure of homeostasis will bring about a sudden collapse. Others suspect that postponing death will lead to a greater prevalence of pre-terminal disability, due to the prevalence of diseases that are largely independent of or even inversely related to mortality. The objectives of preventive medicine are realizable only in so far as they are perceived to be desirable by society. The perception of what is desirable depends not only on objective quantification, but also on a variety of subjective assessments. Preventive medicine must, therefore, allow for the factors that produce these assessments and educate the public to give them appropriate weight.

Adolescent↗