Background: The decade long California Tobacco Control Program is unique to the nation in its duration, emphasis, and level of funding. Programme emphasis is on changing social norms about smoking as a means to discourage smoking and thus reduce the harmful health effects of tobacco to the population. Methods: Data from the 1992 - 93, 1995 - 96, and 1998 - 99 Tobacco Use Supplements to the national Current Population Survey (n> 175 000 each period) were used to examine changes in norms regarding where smoking should "not be allowed at all'' in both California and in the rest of the USA. Venues queried were restaurants, hospitals, work areas, bars, indoor sports venues, and indoor shopping malls. Results: There were substantial increases in the percentages of the adult population (18+ years) stating that smoking should not be allowed in the venues queried in California by 1998 - 99 compared to 1992 - 93; only modest increases were observed in the rest of the USA. In fact, for most venues, the percentages for the rest of the USA were lower in 1998 - 99 than in California in 1992 - 93. Further, the percentage increase over this period in respondents stating that smoking should not be allowed in four or more of the six venues was 30% in California and 23% in the rest of the USA. The most dramatic percentage increase in California occurred among current smokers (93%). Conclusions: A strong, comprehensive tobacco control programme such as California's can influence population norms, including those of smokers, with respect to where smoking should not be allowed.

This study was carried out to determine if the bronchoconstrictive effect of cigarette smoke (CS) is enhanced when airway hyperresponsiveness is induced by ovalbumin (Ova) sensitization, and if so, whether an increase in endogenously released tachykinins is involved. The bronchoconstrictive effects of an acute CS inhalation challenge (15 ml; 50% concentration) were compared between guinea pigs sensitized with aerosolized Ova and matching control animals (receiving saline aerosol). In Ova-sensitized animals, there were marked increases in the numbers of eosinophils and neutrophils in the bronchoalveolar lavage fluid (BALF), which was accompanied by an elevated bronchomotor response to acetylcholine (ACh). The baseline lung resistance (RL) and dynamic pulmonary compliance (Cdyn) were not significantly different between the two groups; however, the same CS inhalation challenge evoked a significantly more intense bronchoconstriction in the Ova-sensitized group (control group: DeltaRL = 68 +/- 8%, DeltaCdyn = -26 +/- 6%; Ova group: DeltaRL = 425 +/- 76%; DeltaCdyn = -47 +/- 8%). The levels of substance P-like immunoreactivity (SP-LI) and calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) measured in the bronchoalveolar lavage (BAL) collected after CS inhalation challenge were also significantly greater in Ova-sensitized animals than in control animals. Furthermore, pretreatment with SR-48968, a selective antagonist of neurokinin-2 (NK(2)) receptor, inhibited more than 85% of the enhanced bronchomotor responses to CS challenge, but did not significantly reduce the airway hyperresponsiveness to ACh in Ova-sensitized guinea pigs. These results show that Ova sensitization induces airway hyperresponsiveness to inhaled CS, and that the endogenous tachykinins evoked by CS-induced activation of lung C fibers play a primary role in this augmented response.

Airway hyperreactivity is a hallmark of asthma. Yet, the role of allergic sensitization in the hyperreactivity remains controversial. This study examined the effects of airborne cockroach allergen (CRa) sensitization on the contractility of bronchial (BSM) and tracheal (TSM) smooth muscle rings to cholinergic stimulations, and to specific antigen, in vitro. Guinea pigs were actively immunized with CRa, 5 mg (high dose, HD), 0.5 mg (low dose, LD), or saline aerosols (2x/day, 5 days/week, for 4 weeks) and challenged by CRa inhalation 5 days after last exposure. Twenty-four hours postchallenge, the contractions of the TSM and BSM to electrical field stimulation (EFS), acetylcholine (ACh), and to CRa were measured in vitro. In addition, the contraction to these stimuli were also examined in the passively sensitized TSM with the sera of CRa-immunized guinea pigs. The contractile responses of actively immunized and passively sensitized tissues to EFS and ACh were very similar to those of control tissues. CRa induced dose-dependent contractions in both actively immunized and passively sensitized, but not in control, tissues. The CRa-induced contraction was stronger in the HD group than in the LD group (p<0.0001). Leukotriene C4/D4 receptor antagonist LY-171883 inhibited the CRa-induced contraction by 86% in actively immunized TSM, and by 9% in the passively sensitized TSM. Pyrilamine inhibited the contraction by 57% in actively immunized TSM and 70% in passively sensitized TSM. The results indicate that CRa sensitization does not cause increased airway smooth muscle contractility to cholinergic stimulations, but induces antigen-specific contractions in vitro. Leukotrienes appear to play a significant role in the CRa-specific contractions, more in the actively immunized than those in the passively sensitized tissues, while histamine exerts a moderate effect on the CRa-induced contractions.

We examine sub-structuring methods for solving large-scale generalized eigenvalue problems from a purely algebraic point of view. We use the term "algebraic sub-structuring" to refer to the process of applying matrix reordering and partitioning algorithms to divide a large sparse matrix into smaller submatrices from which a subset of spectral components are extracted and combined to provide approximate solutions to the original problem. We are interested in the question of which spectral componentsone should extract from each sub-structure in order to produce an approximate solution to the original problem with a desired level of accuracy. Error estimate for the approximation to the small esteigen pair is developed. The estimate leads to a simple heuristic for choosing spectral components (modes) from each sub-structure. The effectiveness of such a heuristic is demonstrated with numerical examples. We show that algebraic sub-structuring can be effectively used to solve a generalized eigenvalue problem arising from the simulation of an accelerator structure. One interesting characteristic of this application is that the stiffness matrix produced by a hierarchical vector finite elements scheme contains a null space of large dimension. We present an efficient scheme to deflate this null space in the algebraic sub-structuring process.