Comparative alpha- and beta-adrenoceptor activity of 2- and 6-ring-chlorinated noradrenaline analogues

The alpha- and beta-adrenoceptor activity of the 2- and 6-ring-chlorinated analogues of noradrenaline (norepinephrine) were evaluated in vitro. The 2-chloro-substituted analogue exhibits a far greater affinity for beta 1-chronotropic receptors than the 6-chloro-substituted analogue, whereas no significant differences are apparent for their alpha-adrenergic affinities.     

Tobacco use, cessation advice to patients and attitudes to tobacco control among physicians in Ukraine.

To examine the relationship between physicians' smoking behaviors and their attitudes toward tobacco use by their patients and tobacco control in the Ukraine, a 70-item questionnaire was administered to 799 general practitioners (287 men and 512 women) working in both rural (278 physicians) and urban (521 physicians) areas of three regions of Ukraine. In all, 13.9% of physicians were current smokers and 21.6% reported being past smokers, with significantly (P<0.001) more men than women being current or past smokers. Odds ratios from logistic regression analysis reveal that physicians who are heavy smokers are 26% less likely to record tobacco use by patients than medium smokers. Heavy smokers devote significantly less effort to providing cessation information to patients and are 36% less likely to support the complete prohibition of smoking in the physician's workplace. Older physicians, female physicians and physicians working in urban areas are significantly more likely than younger, male and rural physicians to advise their patients on smoking. The provision of smoking cessation to patients by general practitioners in Ukraine is influenced by several factors, a major one being the smoking status of the physician. If smoking among physicians declines, this will encourage the patient to consider a serious quit attempt in several ways, most notably: (1) physicians act as societal role models and can promote non-smoking as a norm and (2) the likelihood that a patient will be provided smoking cessation counseling increases.     

Blood flow in the oral mucosa of normal and atherosclerotic rhesus monkeys

Little data is available on regional blood flow in the normal primate oral mucosa and none on that in atherosclerotic animals. Three adult Rhesus monkeys were maintained on a normal diet and 4 on a high fat, high cholesterol diet for 20 months. Radiolabelled microspheres were used to measure blood flow in skin and 16 oral mucosa regions. In normal animals, blood flow ranged from 160.81 to 8.68 ml/min/100 gm tissue. Blood flow in the same regions of atherosclerotic animals showed significantly lower values than in controls, ranging from 65.90 to 1.04 ml/min/100 gms tissue. However, the relative blood flow to the different regions was not significantly different between control and atherosclerotic animals. Histologic examination of tissue from the atherosclerotic animals revealed gross intimal plaques occluding the lumina of the carotids and atherosclerotic lesions in the lingual arteries. It is concluded that the decrease in blood flow in oral mucosa in the atherosclerotic animals is not the result of local changes in the mucosal vasculature but may be related to lesions seen in the major afferent vessels.     

Zinc iodide-osmium staining of membrane-coating granules in keratinized and non-keratinized mammalian oral epithelium

Specimens of keratinized and non-keratinized oral epithelium were examined in the electron microscope after being stained with zinc iodide-osmium. In both types of tissue, reaction was seen in unmyelinated nerves, in the specific granules of epithelial Langerhans cells and within lysosome-like organelles and small vesicles associated with Golgi systems. In keratinized epithelia, the reaction was also present in the membrane-coating granules and between the deepest cells of the keratinized layer. In contrast, the membrane-coating granules of non-keratinized epithelia lacked Zn iodide-osmium staining despite the presence of reaction in adjacent Golgi systems. It is suggested that Zn iodide-osmium stains glycolipid or glycoprotein material in the cell. This material is elaborated in the Golgi systems from which lysosomes and the membrane-coating granules of keratinized tissues are probably derived.     

Penetration pathways different compounds through epidermis and oral epithelia

The permeability of skin and oral mucosa to various compounds has been measured but the actual pathways substances take in traversing the epithelia have not been identified. In this study, radiolabelled cholesterol, ethanol or water were placed on the surface of porcine skin, keratinized gingiva, or nonkeratinized floor of mouth mucosa, and incubated at 37°C for 2 h. The tissue was then snap-frozen, and sectioned in a cryostat, picked up on precoated slides and exposed at -20°C for 40 days for light microscopic autoradiography. Some tissues were freeze-dried and directly embedded in low viscosity resin and prepared for electron microscopic autoradiography Examination of autoradiographs revealed silver grains over, or adjacent to, intercellular spaces. Counts of the grains over the extra- and intracellular compartments were made in random light and electron microscope fields. For all compounds and tissue regions, there were significantly more (p<0.05) grains over the intercellular spaces than over the cells. The results indicate that the intercellular compartment is the predominant route for compounds moving across the superficial barrier layer of epidermis and oral epithelia. The nature of the intercellular material is, thus, a primary determinant of epithelial permeability.