Modification of soft drinks with xanthan gum to minimise erosion: a study in situ.

OBJECTIVE: To compare the erosive effect of a new blackcurrant/calcium drink with xanthan gum, on enamel in situ, with a low erosive product, a conventional fruit beverage and water. DESIGN: The study was single centre, randomised, single blind, 4 treatment crossover design. SETTING: This study, conducted in 2000, employed volunteers working at the Bristol Dental Hospital, UK. SUBJECTS, MATERIALS AND METHODS: 16 subjects (>or=18 years) wore two enamel samples in a removable acrylic appliance. The drinks tested were (A) New blackcurrant/calcium/gum drink (test product), (B) Original blackcurrant/calcium drink, (C) Conventional blackcurrant drink (positive control) and (D) Water (negative control), for 15 day study periods. Drinking was supervised, with 250 ml imbibed four times/day between 9.00am-5.00pm. Profile measurements of specimens were made at baseline, 5, 10 and 15 days. MAIN OUTCOME MEASURES: Paired t-tests compared erosion by surfometry with selected pairs of formulations. RESULTS: Of 16 screened subjects (3 male, 13 female), mean age 34.2 years, 1 subject failed to complete the study. A caused significantly less enamel loss than C, with no statistically significant differences from B at any time points measured. Of 43 treatment emergent adverse events, none were considered related to the study formulations. CONCLUSIONS: A retained low erosive properties similar to B, with additional benefits of taste flexibility and beverage stability.

Development of low erosive carbonated fruit drinks 2. Evaluation of an experimental carbonated blackcurrant drink compared to a conventional carbonated drink.

OBJECTIVE: Previous studies demonstrated that a non-carbonated blackcurrant juice drink with added calcium produced little erosion of enamel in vitro and in situ by comparison with other low pH fruit drinks. The aim of this study is to evaluate the erosive effects in situ of an experimental formulation carbonated drink with added calcium, compared to a conventional carbonated drink over a 20 day period using a similar design as in previous studies. METHOD: The study was a single centre, single blind, randomised placebo controlled three cell crossover design involving 15 volunteers. The test drinks were an experimental carbonated ready-to-drink (RTD) blackcurrant drink, a conventional carbonated RTD orange drink and water. Two enamel samples were retained in situ, in the midline of the hard palate on an upper removable acrylic appliance. Drinks were 250 ml volumes consumed four times per day during 20 working days. Measurements of enamel loss were made on enamel samples after days 2, 5, 10, 15 and 20 by profilometry. RESULTS: The experimental carbonated blackcurrant drink caused significantly less enamel loss than the conventional carbonated orange drink at all time points measured, but was not significantly different from water at days 2, 5 and 20. CONCLUSIONS: This study has shown that it is possible to modify carbonated soft drinks in a manner similarly shown with non-carbonated soft drinks, to minimise dental erosion.

Self-reported smoking, cigarette yields and inhalation biochemistry related to the incidence of coronary heart disease: results from the Scottish Heart Health Study.

BACKGROUND: Smoking is a well-known risk factor for coronary heart disease (CHD). The components of tobacco that cause CHD have not yet been established; nor have the relative dangers of cigarettes of different strengths. METHODS: This is a cohort study of 2,849 men and 2,900 women with no symptoms of CHD at baseline in the Scottish Heart Health Study. RESULTS: In a 7.7 year follow-up, to 1993, there were 123 male and 49 female CHD events. After adjusting for age, cholesterol and blood pressure, men who smoke > or = 20 cigarettes per day have a relative hazard [95% confidence interval (CI)] of 1.93 (1.15-3.24) compared with non-smokers; for women the corresponding relative hazard is 3.81 (2.00-7.27). Biochemical measures (cotinine, thiocyanate and expired-air CO) are closely correlated with self-reported smoking (0.67 < or = r < or = 0.72), and have similar relationships with CHD. Amongst cigarette smokers, relative hazards (third to first tertile), for tar yield are 1.05 (0.54-2.07) for men and 4.00 (1.13-14.18) for women. Nicotine and CO yields give similar results. Hazard ratios associated with heavy smoking and strong cigarettes are thus much higher for women. CONCLUSION: Although smoking was found to have a detrimental effect, this study was unable to suggest a single major cause of CHD. The excess effects found in women compared with men could be due to differences in former smoking habits. Furthermore, risk differences for smoking are slightly greater for men, explained by the relatively low incidence of CHD amongst women.

Heterozygosity for mutations in the ataxia telangiectasia gene is not a major cause of radiotherapy complications in breast cancer patients.

Of patients being treated by radiotherapy for cancer, a small proportion develop marked long-term radiation damage. It is believed that this is due, at least in part, to intrinsic individual differences in radiosensitivity, but the underlying mechanism is unknown. Individuals affected by the recessive disease ataxia telangiectasia (AT) exhibit extreme sensitivity to ionizing radiation. Cells from such individuals are also radiosensitive in in vitro assays, and cells from AT heterozygotes are reported to show in vitro radiosensitivity at an intermediate level between homozygotes and control subjects. In order to examine the possibility that a defect in the ATM gene may account for a proportion of radiotherapy complications, 41 breast cancer patients developing marked changes in breast appearance after radiotherapy and 39 control subjects who showed no clinically detectable reaction after radiotherapy were screened for mutations in the ATM gene. One out of 41 cases showing adverse reactions was heterozygous for a mutation (insertion A at NT 898) that is predicted to generate a truncated protein of 251 amino acids. No truncating mutations were detected in the control subjects. On the basis of this result, the estimated percentage (95% confidence interval) of AT heterozygous patients in radiosensitive cases was 2.4% (0.1-12.9%) and in control subjects (0-9.0%). We conclude that ATM gene defects are not the major cause of radiotherapy complications in women with breast cancer.