Alan Bailey

LOW SERUM-VITAMIN-A AND SUBSEQUENT RISK OF CANCER: Preliminary Results of a Prospective Study

In a prospective study of about 16 000 men, serum samples were collected and stored. Vitamin-A (retinol) levels were later measured in the stored samples from the 86 men who were subsequently notified as having developed cancer and in the stored samples from 172 controls who did not develop cancer. Low retinol levels were associated with an increased risk of cancer. The association was independent of age, smoking habits, and serum-cholesterol level aand was greatest for men who developed lung cancer (mean retinol level 187 i.u./dl compared with 229 i.u./dl for the controls, p < 0.005). The risk of cancer at any site for men with retinol levels in the lowest quintile was 2.2 times greater than the risk for men with levels in the highest quintile (p < 0.025). These results suggest that measures taken to increase serum-retinol levels in man may lead to a reduction in cancer risk.

Carbon monoxide in breath in relation to smoking and carboxyhaemoglobin levels.

Carboxyhaemoglobin (COHb) levels were studied in 11 249 men. The distribution among the 2613 men who smoked cigarettes was well separated from that in 6641 non-smokers (including ex-smokers). The distribution for 2005 cigar and pipe smokers was intermediate, though some of the highest COHb levels occurred in cigar smokers. Using a COHb cut-off level of 2%, 81% of cigarette smokers, 35% of cigar and pipe smokers, and 1.0% of non-smokers had raised COHb levels. In a subsidiary experiment alveolar air samples were collected from 162 smokers and 25 non-smokers using a simple breath sampling technique. Carbon monoxide concentrations in alveolar breath were highly correlated with COHb levels (r = 0.97) indicating that COHb levels can be estimated reliably by measuring the concentration of carbon monoxide in breath. Alveolar carbon monoxide measurement is thus a simple method of estimating whether a person is likely to be a smoker.

HIGH-DENSITY LIPOPROTEIN AND CORONARY RISK FACTORS IN NORMAL MEN

Serum high-density-lipoprotein cholesterol (H.D.L.) was measured in 2568 men attending a screening centre and registered with a medical practitioner in Great Britain. Serum-total-cholesterol (T.C.), serum-triglyceride, serum-glucose, systolic and diastolic blood-pressures, electrocardiogram, chest X-ray, height, weight, cigarette and alcohol history, and a brief assessment of physical activity were also recorded. H.D.L. was inversely related to cigarette-smoking, relative weight, and serum-triglyceride level, and directly related to physical activity, total-cholesterol level, and alcohol consumption. The ratio of H.D.L. to T.C. (H.D.L./T.C.) showed similar significant relationships to the above variables (except that the ratio was negatively correlated with T.C.). In addition the ratio was inversely related to age. These relationships were independent of the other measured variables. Both the H.D.L. and H.D.L./T.C. were inversely related to coronary risk rating. It is suggested that, despite methodological problems, H.D.L. is a useful biochemical measurement to add to a coronary risk profile.

SERUM COTININE LEVELS IN PIPE SMOKERS: EVIDENCE AGAINST NICOTINE AS CAUSE OF CORONARY HEART DISEASE

Serum levels of cotinine (a principal metabolite of nicotine) were studied in men who did not smoke (28), and in men who smoked cigarettes only (150), cigars only (70), and pipes only (56). The mean cotinine level for pipe smokers was 389 ng/ml, significantly higher than the mean level for cigarette and cigar smokers (306 and 121 ng/ml, respectively); no cotinine was detected in the serum from any of the non-smokers. Large prospective studies have shown that pipe smokers have no material excess risk of coronary heart disease but cigarette smokers do, so that our observations indicate that nicotine is unlikely to be the major cause of the excess coronary heart disease mortality in cigarette smokers.

Assessment of whether in-hospital mortality for lobectomy is a useful standard for the quality of lung cancer surgery: retrospective study

Objectives To calculate in-hospital mortality after lobectomy for primary lung cancer in the United Kingdom; to explore the validity of using such data to assess the quality of UK thoracic surgeons; and to investigate the relation between in-hospital mortality and the number of procedures performed by surgeons. Design Retrospective study. Setting 36 departments dealing with thoracic surgery in UK hospitals. Participants 4028 patients who had undergone lobectomy for primary lung cancer by one of 102 surgeons. Main outcome measures In-hospital mortality in relation to individual surgeons, among all patients, and among each of five groups of patients defined by the number of operations performed by the surgeon. Results 103 patients (2.6%, 95% confidence interval 2.1% to 3.1%) died after surgery during the same hospital admission. No significant difference was found for in-hospital mortality between the five groups. Conclusions The number of procedures performed by a thoracic surgeon is not related to in-hospital mortality. Reporting data on in-hospital mortality after lobectomy for primary lung cancer is a poor tool for measuring a surgeons performance.

CARBOXYHÆMOGLOBIN LEVELS IN SMOKERS OF FILTER AND PLAIN CIGARETTES

Blood-carboxyhaemoglobin (COHb) levels were studied in 343 healthy male cigarette smokers aged 35-64. The mean COHb level was 30% higher in the 248 men who smoked unventilated filter cigarettes than in the 41 men who smoked plain cigarettes, after adjusting for the number of cigarettes smoked (P less than 0.001). This result was consistent with the carbon-monoxide (CO) yields of these cigarettes: on average, the unventilated filter cigarettes had yields 25% higher than the plain ones. The mean COHb level was 7% higher in the 54 men who smoked ventilated cigarettes than in men who smoked plain cigarettes. Although this difference was not statistically significant, it was in the opposite direction to the result which might have been expected on the basis of the CO yields of these cigarettes: on average the ventilated filter cigarettes had yields 21% lower than the plain ones. The medical implications of these results are uncertain. COHb levels of 3-4% or more can exacerbate angina pectoris and intermittent claudication, and it is, therefore, of concern that COHb levels are higher in smokers of filter cigarettes than in smokers of plain cigarettes. However, any assessment of risk associated with either type of cigarette should take account of the observation from other studies that filter cigarettes are associated with a lower mortality from lung cancer than are plain cigarettes.

Anthropometric, physiological and biochemical differences between urban and rural Maasai☆

Abstract Measurements were made on samples of urban and rural Maasai, and the values of a number of biochemical, anthropometric and physiological parameters were compared between the two groups. Significant differences were found for weight, upper arm circumference, ponderal index, triceps and subscapular skinfolds, pulse rate and cholesterol. In particular, the mean cholesterol level in the urban sample was much higher than in the rural Maasai. No significant difference was found for triglyceride, fibrinogen or either systolic or diastolic blood pressure. A control group of European males included in the study was found to differ significantly from the rural but not the urban Maasai in the anthropometric variables. Blood pressure and cholesterol levels were significantly higher in the Europeans than in either of the Maasai groups. Possible causes for the differences between the two Maasai groups are discussed.

Inhaling habits among smokers of different types of cigarette.

Inhaling habits were studied in 1316 men who freely smoked their usual brands of cigarette. An index of inhaling was calculated for each person by dividing the estimated increase in carboxyhaemoglobin level from a standard number of cigarettes by the carbon monoxide yield of the cigarette smoked. Smokers of ventilated filter cigarettes inhaled 82% more than smokers of plain cigarettes (p less than 0.001) and those who smoked unventilated filter cigarettes inhaled 36% more (p less than 0.001). Cigarette consumption was similar among smokers of each type of cigarette. Assuming that the intake of tar and nicotine is proportional to the inhaling index, the intake in either group of filter cigarette smokers would have been less than that in plain cigarette smokers. Among smokers of unventilated cigarettes, however, the intake would not have been much less.

A new epoxidation catalyst: the reactivity and X-ray crystal structure of [RuO2(bipy){IO3(OH)3}]·1.5H2O (bipy = 2,2′-bipyridine)

The crystal structure of [RuO2(bipy){IO3(OH)3}]·1.5H2O 1 is reported: with NaIO4 or NBun4IO4 as cooxidant it is an efficient catalyst for alkene epoxidations under mild conditions; it also oxidises primary alcohols to aldehydes and secondary alcohols to ketones.

Heteropolyperoxo- and isopolyperoxo-tungstates and-molybdates as catalysts for the oxidation of tertiary amines, alkenes and alcohols

The catalytic oxidation of tertiary amines to the corresponding N-oxides by [XO4{MO(O2)2}4]3–(X = P or As, M = Mo or W) and by [M2O3(O2)4]2– with H2O2 as co-oxidant has been studied. Epoxidation of alkenes and oxidation of alcohols by [M2O3(O2)4]2– with H2O2 as co-oxidant has also been examined and compared with that effected by [XO4{MO(O2)2}4]3–. A possible structure for [M2O3(O2)4]2– is suggested.