Leucoplakia of the oral cavity, smoking and arylhydrocarbon-hydroxylase inducibility

Smoking cessation practices in dental offices

We have surveyed the health promotion efforts of dentists and dental hygienists in general dental practice in Chittenden County, Vermont, in relation to smoking. The response rate was 61 percent. Smoking issues were addressed by 76 percent of dentists and 81 percent of dental hygienists in approximately one quarter of their smoking patients. Although the majority of both dentists and dental hygienists advised their patients to change their smoking behavior, their advice was usually to cut down rather than to quit. Most of the respondents--78 percent of dentists and 93 percent of dental hygienists--considered it appropriate to give advice about smoking during visits for routine dental care and 68 percent and 89 percent, respectively, were willing to learn brief methods of advising their patients about smoking. Experience with giving advice about smoking and agreement that it was appropriate to give such advice were both strongly related to willingness to learn brief methods of giving such advice. In individual dental practices, there were virtually no correlations between the dentist's and the dental hygienist's behaviors as far as the proportion of patients from whom a smoking history was taken, the proportion of smokers advised about smoking, the content of the advice, or the nature of the advice. Only nine percent of dentists and 11 percent of dental hygienists were current smokers.

Distribution and reproducibility of aryl hydrocarbon hydroxylase inducibility in a prospective population study of middle-aged male smokers and nonsmokers

Aryl hydrocarbon hydroxylase (AHH) inducibility was determined in a lymphoblast test system in 2,000 consecutive middle-aged male smokers, 304 ex-smokers, and 218 never-smokers in the same birth-year cohorts. Intraindividual, intraobserver, and interobserver, as well as temporal, reproducibility was checked in a special double-blind quadruplet sample series from 20 other consecutive middle-aged men. The results showed a three-modal phenotype distribution of AHH inducibility with high (fold induction greater than or equal to 3.6), intermediate (2.6-3.6) and low (less than or equal to 2.5) levels ranging between 7.6% to 10.5%, 38.5% to 43.0%, and 46.5% to 53.9%, respectively, in all the smoking categories. The reproducibility of the measurements was excellent, with one-way variance in the order of 0.007 to 0.033, and the applied assay method can therefore be used in large-scale prospective population investigations. Such are required in order to establish a cause-effect association between high AHH inducibility and smoking-related malignancies of the respiratory tract and oral cavity, as has been suggested from earlier retrospective studies in more limited clinical materials of cancers and precanceroses of these varieties.

Mutagen sensitivity, smoking habits and enzyme induction in healthy middle-aged men

Unscheduled DNA synthesis (UDS) (excision-repair) of N-acetoxy-2-acetylaminofluorene (NA-AAF) damage to the DNA of human lymphocytes and levels of 3H-labeled NA-AAF bound to the DNA (carcinogen binding) of lymphocytes after 18 hr of culturing were measured in a consecutive subsample of healthy middle-aged males attending a multiphasic health screening program at the Department of Preventive Medicine in Malmö during 3 weeks in November-December 1981, and compared relative to their smoking habits, body weight, serum cholesterol, and gamma-glutamyltransferase levels as well as aryl hydrocarbon hydroxylase inducibility. This study group numbered 66 males and was uniform in sex, age, and investigation time. No case of significant arterial hypertension was present. The UDS and carcinogen binding results showed no correlation with the other factors measured, with the exception of smoking which was strongly (P less than 0.01) associated with increasing levels of both the UDS and carcinogen binding values. It is concluded that under ordinary circumstances smoking may represent the most important exogenous factor which may modulate risk to cardiovascular disease and cancer by influencing individual mutagen sensitivity.

Aryl hydrocarbon hydroxylase induction levels in patients with malignant tumors associated with smoking

The levels of aryl hydrocarbon hydroxylase (AHH) inducibility were assessed in 173 patients with cancers statistically associated with smoking, i.e., squamous cell and transitional cell carcinomas, at various sites. In 34 patients with carcinomas of the oral cavity, 41 patients with laryngeal carcinomas, and 22 patients with pulmonary carcinomas there was a highly significant overrepresentation of high inducers, whereas 30 patients with carcinomas of the renal pelvis and ureter and 46 patients with urinary bladder carcinomas did not differ significantly in this respect from a control population comprising 92 subjects with no history of neoplastic disease. The results add further support to the concept of AHH as a major activator of carcinogens belonging to the group of polycyclic aromatic hydrocarbons (PAH) when these affect the oral cavity and/or the respiratory tract. The role of AHH in urothelial carcinogenesis seems to be less explicit.

A method for assaying aryl hydrocarbon hydroxylase in man using fibroblasts cultured in vitro from oral mucosa

Animal studies have linked aryl hydrocarbon hydroxylase (AHH) with cancer induction by polycyclic aromatic hydrocarbons (PAH), but the relationship between the activation of PAH by AHH and cancer induction in man is unclear. Studies using human lymphocytes to investigate this relationship have produced conflicting results. This report describes a technique for assaying AHH in fibroblasts isolated and cultured from normal human oral mucosa. Fibroblasts were cultured from normal portions of routine oral mucosal biopsy specimens obtained from 6 patients, and AHH activity was found in fibroblasts cultured from all the specimens. AHH activity was induced by 1,2-benzanthracene and reached a peak after 48 h. The assay had a pH optimum of 8.6 and an absolute requirement for reduced nicotinamide-adenine dinucleotide phosphate. The fibroblasts maintained their inducibility of AHH through 11 cell passages. Fibroblasts cultured from oral mucosal biopsy specimens offer several advantages over other systems for comparison of individual differences in AHH activity in man, including the consistent presence of inducible AHH activity, stability of enzyme activity in culture, provision of ample number of cells for study, and availability of oral mucosal specimens from patients having routine diagnostic biopsies.

Community-based preventive medical department for individual risk factor assessment and intervention in an urban population

In Malmö, a southern Swedish city of about 230,000 inhabitants, an institute of preventive medicine within the medical department of Malmö General Hospital has been in operation since 1975. It is directed against the major middle-aged internal medical health risks and complications such as cardiovascular diseases, diabetes mellitus, and alcohol complications, and contains both screening and intervention resources, mediated predominantly by an individually orientated approach both in the function of the department and in the preventive medical actions. The design, feasibility, and some of the quantitative results of the program are described.