There is strong scientific evidence from clinical and epidemiological studies that tobacco use, particularly cigarette smoking, is linked to periodontal disease as well as other serious but less common oral health diseases. Given the strength of this evidence, dentists must include tobacco cessation services (TCS) as part of their routine care. This paper describes barriers to the adoption of TCS as identified by Alberta dentists participating in a randomized intervention trial and discusses strategies for overcoming these barriers. As well, suggestions are made to professional associations and educational institutes on ways to increase the incorporation of tobacco cessation into professional practice standards.
Comment In: J Can Dent Assoc. 2001 Mar;67(3):12711315384
Tar particulates from cigarette smoke contain compounds with affinity for the Ah receptor. The sidestream activity is larger than that of the mainstream with a ratio of about 5. The compounds causing the affinity appear in the neutral fraction after chemical fractionation excluding basic and acidic components as major contributors to the affinity. The affinity cannot be explained by benzo[a]pyrene and other polycyclic aromatic hydrocarbons but it might be caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds and by oxidized tryptophan derivatives.
Levels of adenylate metabolism have been studied in cells of Nicotiana tabacum growing in vitro, and in root apex extracts of Pisum sativum irradiated at the 95-in. isochronous cyclotron U-240, Institute for Nuclear Research, Ukrainian National Academy of Sciences, Kyiv. Particle beams of accelerated helium ions with energy 9.34 keV/micrometer were used. Replacement and rapid freezing of the irradiated plants samples in liquid nitrogen were carried out with a manipulator and a remote control system. After doses of 5, 20, 50, and 100 Gy of gamma-irradiation, as well as 50 and 100 Gy 4He irradiation, the cellular ATP/ADP ratio increased during early stages of the response. This effect was absent at higher doses and after exposure to sparesly-ionizing radiation, when a rapid decline in the cellular ATP concentration and the ATP/ADP ratio occurred.
In this study we have constructed a number of plants (cybrids), in which the nuclear genome of Nicotiana plumbaginifolia is combined with the plastome of Atropa belladonna, or the nuclear genome of N. tabacum with plastomes of Lycium barbarum, Scopolia carniolica, Physochlaine officinalis or Nolana paradoxa. Our biochemical and immunological analyses prove that in these cybrids the biogenesis of the chlorophyll a/b binding proteins (CAB) of the light harvesting complex II (LHCII) is altered. Besides normal sized CAB polypeptides of 27, 25.5 and 25 kDa, which become less abundant, the cybrids analyzed have additional polypeptides of 26, 24.5 and 24 kDa. Direct protein micro-sequencing showed that at least two truncated 26 kDa CAB polypeptides in plant cells containing a nucleus of N. plumbaginifolia and plastids of A. belladonna are encoded by the type 1 Lhcb genes. These polypeptides are 11-12 amino acids shorter at the N-terminus than the expected size. Based on the available data we conclude that the biogenesis of the LHCII in vivo may depend on plastome-encoded factor(s). These results suggest that plastome-encoded factors that cause specific protein degradation and/or abnormal processing might determine compartmental genetic incompatibility in plants.