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Use of smokeless tobacco products is common worldwide, with increasing consumption in many countries. Although epidemiological data from the USA and Asia show a raised risk of oral cancer (overall relative risk 2.6 [95% CI 1.3-5.2]), these are not confirmed in northern European studies (1.0 [0.7-1.3]). Risks of oesophageal cancer (1.6 [1.1-2.3]) and pancreatic cancer (1.6 [1.1-2.2]) have also increased, as shown in northern European studies. Results on lung cancer have been inconsistent, with northern European studies suggesting no excess risk. In India and Sudan, more than 50% of oral cancers are attributable to smokeless tobacco products used in those countries, as are about 4% of oral cancers in US men and 20% of oesophageal and pancreatic cancers in Swedish men. Smokeless tobacco products are a major source of carcinogenic nitrosamines; biomarkers of exposure have been developed to quantify exposure as a framework for a carcinogenesis model in people. Animal carcinogenicity studies strongly support clinical results. Cancer risk of smokeless tobacco users is probably lower than that of smokers, but higher than that of non-tobacco users. [ABSTRACT FROM AUTHOR]

Occupied and unoccupied electronic states in tetra- tert-butyl-azobenzene (TBA) absorbed on Ag(111) have been investigated by one-photon and two-photon photoemission spectroscopy. These measurements allow the quantitative determination of energetic positions of the highest occupied (HOMO) and the lowest unoccupied molecular orbital (LUMO) as well as the n=1 image potential state. The assignment of the electronic states are supported by quantum chemical calculations. Experimentally a HOMO–LUMO gap of 2.85 eV is observed, whereas the gap obtained from the calculated molecular orbital energies is 0.92 eV larger. This discrepancy can be explained by image charge screening. Furthermore, two unoccupied final states located 0.18 and 0.43 eV above the vacuum level, respectively, have been identified. [ABSTRACT FROM AUTHOR]

Objective: To determine smoking behaviour, acceptability, and toxin exposure when smokers switch to the potential reduced exposure product-Omni cigarette. Design: 12 week randomised, crossover study of Omni versus own cigarettes. Participants: 19 light/ultralight and 15 regular smokers. Outcomes: Cigarettes/day, smoking topography, craving, withdrawal symptoms, urinary cotinine plus its glucuronide (total cotinine), nicotine plus its glucuronide (total nicotine), and carcinogen metabolites (4-(methylnitrosamino)-1 -(3-pyridyl)-1-butanol plus its glucuronides and 1 -hydroxypyrene). Results: When switched to Omni, smokers smoked the same number of cigarettes/day, smoked Omni cigarettes less intensely (total puff volume = -11%) and had slightly lower total cotinine (-18%) levels than their own cigarettes, but had a slightly greater carbon monoxide boost/cig (+21%). Craving and withdrawal ratings were similar with Omni and own cigarettes. Carcinogen metabolite levels were somewhat but not significantly lower with Omni. About half of smokers rated Omni as better for their health and about two thirds stated it was weaker and worse tasting than their own cigarettes. Conclusions: Although Omni may be an adequate behavioural and pharmacological substitute for traditional cigarettes, it may not decrease carcinogen exposure and may increase carbon monoxide. Replications with larger sample sizes and longer follow up are needed. These results indicate the need for regulation of reduced exposure and reduced risk claims. [ABSTRACT FROM AUTHOR]

Objective: To review the literature on carcinogen derived biomarkers of exposure to secondhand tobacco smoke (SHS). These biomarkers are specifically related to known carcinogens in tobacco smoke and include urinary metabolites, DNA adducts, and blood protein adducts. Method: Published reviews and the current literature were searched for relevant articles. Results: The most consistently elevated biomarker in people exposed to SHS was 4-(methylnitrosamino)-1- (3-pyridyl)-1-butanol (NNAL) and its glucuronides (NNAL-Gluc), urinary metabolites of the tobacco specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). The tobacco specificity of this biomarker as well as its clear relation to an established lung carcinogen are particularly appropriate for its application in studies of SHS exposure. Conclusion: The results of the available carcinogen derived biomarker studies provide biochemical data which support the conclusion, based on epidemiologic investigations, that SHS causes lung cancer in non-smokers. [ABSTRACT FROM AUTHOR]

Objective: To explore the stability of diverse manic presentations across manic recurrences. Method: A total of 253 bipolar patients who experienced two or more hospitalizations, because of consecutive manic (or mixed) episodes, during a 20-year period were included. All patients had second hospitalizations with an mean interval of 773 days, while 126 and 91 patients had third and fourth hospitalizations with mean intervals of 1559 and 2237 days from the index hospitalization, respectively. Seven symptom scores, previously factor-validated, were calculated. Results: Depressive mood, irritable aggression, psychomotor/thought inhibition, mania, emotional lability/agitation and psychosis were moderately correlated across the index and subsequent hospitalizations. Conclusion: A majority of diverse manic presentations were stable across manic recurrences. The stability was not restricted to two consecutive recurrences but appeared widespread over the long-term course of bipolar disorder. The finding may serve for the development of more effective long-term treatment strategies and a clinically more reasonable subtyping of mania. [ABSTRACT FROM AUTHOR]

Adverse outcomes from tobacco use may take decades to develop. Biomarkers are measures that can be used in the early stages of tobacco use to assess exposure to tobacco toxins or to predict adverse health outcomes with which they are associated. Examples of biomarkers include specific chemical components of tobacco or their metabolites; early biochemical, histological, or physiological effects; and early health effects. Mechanistically relevant and quantitatively valid biomarkers are essential for assessing the ultimate impact of new products, treatments, preventive measures, and public health policies on tobacco-related disease. The tobacco industry's recent introduction of a variety of new tobacco products or devices with implied claims of reduced health risks highlights the need to develop methods for assessing their potential for benefit or harm. A wide variety of biomarkers for tobacco exposure or harm has been studied. Although many questions about their use remain unanswered, substantial data exist regarding their validity and utility. This conference reviewed both the general issues surrounding biomarker use and the current state of knowledge regarding the most widely studied and promising biomarkers. [ABSTRACT FROM AUTHOR]

Discusses possible risk factors for childhood central nervous system cancer. Suggestion that N-Nitroso compounds play an etiologic role in childhood brain cancer; Possible role of polymaviruses in the development of brain cancer; Reduction in the risk of brain cancer from multivitamins; Possible carcinogenicity of pesticides.

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