Myosin functional domains encoded by alternative exons are expressed in specific thoracic muscles of Drosophila.

The Drosophila 36B muscle myosin heavy chain (MHC) gene has five sets of alternatively spliced exons that encode functionally important domains of the MHC protein and provide a combinatorial potential for expression of as many as 480 MHC isoforms. In this study, in situ hybridization analysis has been used to examine the complexity and muscle specificity of MHC isoform expression in the fibrillar indirect flight muscle (IFM), the tubular direct flight muscles (DFM) and tubular tergal depressor of the trochanter muscle (TDT), and the visceral esophageal muscle in the adult thorax. Our results show that alternative splicing of the MHC gene transcripts is precisely regulated in these thoracic muscles, which express three MHC isoforms. Individual thoracic muscles each express transcripts of only one isoform, as detectable by in situ hybridization. An apparently novel fourth MHC isoform, with sequence homology to the rod but not to the head domain of the 36B MHC, is expressed in two direct flight muscles. These findings form a basis for transgenic experiments designed to analyze the muscle-specific functions of MHC domains encoded by alternative exons.

Reported awareness of tobacco advertising and promotion in China compared to Thailand, Australia and the USA.

BACKGROUND: China currently does not have comprehensive laws or regulations on tobacco advertising and promotion, although it ratified the World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) in October 2005 and promised to ban all tobacco advertising by January 2011. Much effort is needed to monitor the current situation of tobacco advertising and promotion in China. OBJECTIVE: This study aims to examine levels of awareness of tobacco advertising and promotion among smokers in China as compared to other countries with different levels of restrictions. METHODS: One developing country (Thailand) and two developed countries (Australia and the USA) were selected for comparison. All four countries are part of the International Tobacco Control (ITC) Policy Evaluation Survey project. Between 2005 and 2006, parallel ITC surveys were conducted among adult smokers (at least smoked weekly) in China (n = 4763), Thailand (n = 2000), Australia (n = 1767) and the USA (n = 1780). Unprompted and prompted recall of noticing tobacco advertising and promotion were measured. RESULTS: Chinese respondents reported noticing tobacco advertisements in a range of channels and venues, with highest exposure levels on television (34.5%), billboards (33.4%) and in stores (29.2%). A quarter of respondents noticed tobacco sponsorships, and a high level of awareness of promotion was reported. Cross-country comparison reveals that overall reported awareness was significantly higher in China than in Thailand (particularly) and Australia, but lower than in the USA. CONCLUSIONS: There is a big gap between China and the better-performing countries such as Thailand and Australia regarding tobacco promotion restrictions. China needs to do more, including enhanced policy and more robust enforcement.

Impact of graphic and text warnings on cigarette packs: findings from four countries over five years.

OBJECTIVES: To examine the impact of health warnings on smokers by comparing the short-term impact of new graphic (2006) Australian warnings with: (i) earlier (2003) United Kingdom larger text-based warnings; (ii) and Canadian graphic warnings (late 2000); and also to extend our understanding of warning wear-out. METHODS: The International Tobacco Control Policy Evaluation Survey (ITC Project) follows prospective cohorts (with replenishment) of adult smokers annually (five waves: 2002-2006), in Canada, United States, UK and Australia (around 2000 per country per wave; total n = 17 773). Measures were of pack warning salience (reading and noticing); cognitive responses (thoughts of harm and quitting); and two behavioural responses: forgoing cigarettes and avoiding the warnings. RESULTS: All four indicators of impact increased markedly among Australian smokers following the introduction of graphic warnings. Controlling for date of introduction, they stimulated more cognitive responses than the UK (text-only) changes, and were avoided more, did not significantly increase forgoing cigarettes, but were read and noticed less. The findings also extend previous work showing partial wear-out of both graphic and text-only warnings, but the Canadian warnings have more sustained effects than UK ones. CONCLUSIONS: Australia's new health warnings increased reactions that are prospectively predictive of cessation activity. Warning size increases warning effectiveness and graphic warnings may be superior to text-based warnings. While there is partial wear-out in the initial impact associated with all warnings, stronger warnings tend to sustain their effects for longer. These findings support arguments for governments to exceed minimum FCTC requirements on warnings.

What happened to smokers' beliefs about light cigarettes when "light/mild" brand descriptors were banned in the UK? Findings from the International Tobacco Control (ITC) Four Country Survey.

AIM: This paper examines how beliefs of smokers in the UK were affected by the removal of "light" and "mild" brand descriptors, which came into effect on 30 September 2003 for Member States of the European Union (EU). PARTICIPANTS: The data come from the first four waves (2002-2005) of the International Tobacco Control Policy Evaluation (ITC) Four-Country Survey, an annual cohort telephone survey of adult smokers in Canada, USA, UK and Australia (15 450 individual cases). DESIGN: The UK ban on misleading descriptors occurred around the second wave of data collection in the ITC survey, permitting us to compare beliefs about light cigarettes among adult smokers in the UK before and after the ban, with beliefs in the three other ITC countries unaffected by the ban. RESULTS: There was a substantial decline in reported beliefs about the benefits of light cigarettes in the UK following the policy change and an associated public information campaign, but by 2005 (ie, wave 4), these beliefs rebounded slightly and the change in beliefs was no greater than in the USA, where there was no policy change. CONCLUSIONS: The findings reveal that high levels of misperceptions about light cigarettes existed among smokers in all four countries before and after the EU ban took effect. We cannot conclude that the policy of removing some aspects of misleading labels has been effective in changing beliefs about light cigarettes. Efforts to correct decades of consumer misperceptions about light cigarettes must extend beyond simply removing "light" and "mild" brand descriptors.

Elements involved in oxygen regulation of the Saccharomyces cerevisiae CYC7 gene.

The CYC7 gene of Saccharomyces cerevisiae encodes the minor species, iso-2, of the cytochrome c protein. Its expression is governed by two regulatory sequences upstream from the gene: a positive site which stimulates transcription 240 base pairs 5' from the protein-coding sequence (-240) and a negative site which inhibits transcription at -300. In this study, the nature of the positive site and its relationship to the negative site has been investigated. Expression of the CYC7 gene is weakly inducible by oxygen. This effect was greatly enhanced by the semidominant CYP1-16 mutation in the trans-acting gene CYP1. The weak oxygen regulation in wild-type cells and the enhanced induction in CYP1-16 mutants were found to be mediated through the positive site. A mutational analysis of this site implicated at least part of a tandem, direct repeat of 9 base pairs as essential for the functioning of this site. The relationship between the positive and negative sites was investigated by comparing the expression of the intact gene with that of derivatives lacking either one or the other site. The expression of the gene containing only the negative site was actually stimulated anaerobically, while the gene containing the positive site alone, although having higher expression aerobically than anaerobically, had higher anaerobic expression than did the intact gene. Thus, it appeared that the combination of the positive and negative sites suppressed anaerobic expression. A model which attempts to explain these properties of the two sites and account for the regulation of the expression of the intact gene is presented.

Effects of the 2003 advertising/promotion ban in the United Kingdom on awareness of tobacco marketing: findings from the International Tobacco Control (ITC) Four Country Survey.

BACKGROUND: In February 2003, a comprehensive ban on tobacco promotion came into effect in the United Kingdom, which prohibited tobacco marketing through print and broadcast media, billboards, the internet, direct mail, product placement, promotions, free gifts, coupons and sponsorships. OBJECTIVE: To investigate the impact of the UK's comprehensive ban on tobacco promotion on adult smokers' awareness of tobacco marketing in the UK relative to Canada, the United States and Australia. DESIGN: A total of 6762 adult smokers participated in two waves of a random digit dialled telephone survey across the four countries. Wave 1 was conducted before the UK ban (October-December 2002) and Wave 2 was conducted after the UK ban (May-September 2003). KEY MEASURES: Awareness of a range of forms of tobacco marketing. RESULTS: Levels of tobacco promotion awareness declined significantly among smokers in the UK after implementation of the advertising ban. Declines in awareness were greater in those channels regulated by the new law and change in awareness of tobacco promotions was much greater in the UK than the other three countries not affected by the ban. At least in the short term, there was no evidence that the law resulted in greater exposure to tobacco promotions in the few media channels not covered by the law. Notwithstanding the apparent success of the UK advertising ban and the controls in other countries, 9-22% of smokers in the four countries still reported noticing things that promoted smoking "often or very often" at Wave 2. CONCLUSIONS: The UK policy to ban tobacco advertising and promotion has significantly reduced exposure to pro-tobacco marketing influences. These findings support the effectiveness of comprehensive bans on advertising and promotion, as included in the Framework Convention on Tobacco Control.

The conceptual framework of the International Tobacco Control (ITC) Policy Evaluation Project.

This paper describes the conceptual model that underlies the International Tobacco Control Policy Evaluation Project (ITC Project), whose mission is to measure the psychosocial and behavioural impact of key policies of the Framework Convention on Tobacco Control (FCTC) among adult smokers, and in some countries, among adult non-smokers and among youth. The evaluation framework utilises multiple country controls, a longitudinal design, and a pre-specified, theory-driven conceptual model to test hypotheses about the anticipated effects of specific policies. The ITC Project consists of parallel prospective cohort surveys of representative samples of adult smokers currently in nine countries (inhabited by over 45% of the world's smokers), with other countries being added in the future. Collectively, the ITC Surveys constitute the first-ever international cohort study of tobacco use. The conceptual model of the ITC Project draws on the psychosocial and health communication literature and assumes that tobacco control policies influence tobacco related behaviours through a causal chain of psychological events, with some variables more closely related to the policy itself (policy-specific variables) and other variables that are more downstream from the policy, which have been identified by health behaviour and social psychological theories as being important causal precursors of behaviour (psychosocial mediators). We discuss the objectives of the ITC Project and its potential for building the evidence base for the FCTC.

Support for and reported compliance with smoke-free restaurants and bars by smokers in four countries: findings from the International Tobacco Control (ITC) Four Country Survey.

OBJECTIVE: To explore determinants of support for and reported compliance with smoke-free policies in restaurants and bars across the four countries of the International Tobacco Control (ITC) Four Country Survey. DESIGN: Separate telephone cross-sectional surveys conducted between October and December 2002 with broadly representative samples of over 2000 adult (>or=18 years) cigarette smokers in each of the following four countries: the United States, Canada, the United Kingdom, and Australia. OUTCOME MEASURES: Support for smoke-free policies in restaurants and pubs/bars and reported compliance with existing policies. RESULTS: Reported total bans on indoor smoking in restaurants varied from 62% in Australia to 5% in the UK. Smoking bans in bars were less common, with California in the USA being the only major part of any country with documented bans. Support for bans in both restaurants and bars was related to the existence of bans, beliefs about passive smoking being harmful, lower average cigarette consumption, and older age. Self-reported compliance with a smoking ban was generally high and was associated with greater support for the ban. CONCLUSIONS: Among current cigarette smokers, support for smoking bans was associated with living in a place where the law prohibits smoking. Smokers adjust and both accept and comply with smoke-free laws. Associates of support and compliance are remarkably similar across countries given the notably different levels of smoke-free policies.

Cigarette purchase patterns in four countries and the relationship with cessation: findings from the International Tobacco Control (ITC) Four Country Survey.

BACKGROUND: Higher cigarette prices result in decreased cigarette consumption, but some smokers may seek lower-taxed cigarette sources. This price avoidance behaviour likely dampens the health impact of higher cigarette prices although it has not been thoroughly studied. OBJECTIVE: To describe the characteristics of smokers who purchase low/untaxed cigarettes and to examine how this behaviour is associated with subsequent changes in smoking behaviours. METHODS: Telephone survey data from 8930 smokers from the International Tobacco Control (ITC) Four Country Survey (ITC-4) were used to assess cigarette purchase patterns and smoking behaviours in Wave 1 conducted from October to December 2002 and subsequently followed seven months later in Wave 2. Respondents' smoking status, attempts to quit, amount smoked, and cigarette purchase patterns were assessed in both waves. RESULTS: Rates of purchase from a low/untaxed source at the respondents' last cigarette purchase differed notably between countries at Wave 1, from less than 1% in Australia to 15% in the United Kingdom. In the UK, but not the other countries, this increased significantly to 20% at Wave 2. Smokers who were older, white/English speakers, had higher incomes, and had higher levels of education were more likely to report purchasing cigarettes from a low/untaxed source on their last purchase. Those who reported purchasing from a low/untaxed source on their last purchase at Wave 1 were less likely to have tried to quit smoking quit smoking by Wave 2 (relative risk 0.70, p < 0.01), while no overall significant association with smoking cessation was observed. CONCLUSION: Data from this study indicate that there are lower levels of making a quit attempt among purchasers of low/untaxed cigarettes compared to purchasers of full-priced cigarettes. The availability of low/untaxed cigarettes may mitigate the influence of increases in cigarette prices.

Methods of the International Tobacco Control (ITC) Four Country Survey.

This paper outlines the design features, data collection methods and analytic strategies of the International Tobacco Control (ITC) Four Country Survey, a prospective study of more than 2000 longitudinal respondents per country with yearly replenishments. This survey possesses unique features that sets it apart among surveys on tobacco use and cessation. One of these features is the use of theory-driven conceptual models. In this paper, however, the focus is on the two key statistical features of the survey: longitudinal and "quasi-experimental" designs. Although it is often possible to address the same scientific questions with a cross-sectional or a longitudinal study, the latter has the major advantage of being able to distinguish changes over time within individuals from differences among people at baseline (that is, differences between age and cohort effects). Furthermore, quasi-experiments, where countries not implementing a given new tobacco control policy act as the control group to which the country implementing such a policy will be compared, provide much stronger evidence than observational studies on the effects of national-level tobacco control policies. In summary, application of rigorous research methods enables this survey to be a rich data resource, not only to evaluate policies, but also to gain new insights into the natural history of smoking cessation, through longitudinal analyses of smoker behaviour.

Reductions in tobacco smoke pollution and increases in support for smoke-free public places following the implementation of comprehensive smoke-free workplace legislation in the Republic of Ireland: findings from the ITC Ireland/UK Survey.

OBJECTIVE: To evaluate the psychosocial and behavioural impact of the first ever national level comprehensive workplace smoke-free law, implemented in Ireland in March 2004. DESIGN: Quasi-experimental prospective cohort survey: parallel cohort telephone surveys of national representative samples of adult smokers in Ireland (n = 769) and the UK (n = 416), surveyed before the law (December 2003 to January 2004) and 8-9 months after the law (December 2004 to January 2005). MAIN OUTCOME MEASURES: Respondents' reports of smoking in key public venues, support for total bans in those key venues, and behavioural changes due to the law. RESULTS: The Irish law led to dramatic declines in reported smoking in all venues, including workplaces (62% to 14%), restaurants (85% to 3%), and bars/pubs (98% to 5%). Support for total bans among Irish smokers increased in all venues, including workplaces (43% to 67%), restaurants (45% to 77%), and bars/pubs (13% to 46%). Overall, 83% of Irish smokers reported that the smoke-free law was a "good" or "very good" thing. The proportion of Irish homes with smoking bans also increased. Approximately 46% of Irish smokers reported that the law had made them more likely to quit. Among Irish smokers who had quit at post-legislation, 80% reported that the law had helped them quit and 88% reported that the law helped them stay quit. CONCLUSION: The Ireland smoke-free law stands as a positive example of how a population-level policy intervention can achieve its public health goals while achieving a high level of acceptance among smokers. These findings support initiatives in many countries toward implementing smoke-free legislation, particularly those who have ratified the Framework Convention on Tobacco Control, which calls for legislation to reduce tobacco smoke pollution.

Use of synthetic peptides in the production and characterization of antibodies directed against predetermined specificities in rat immunoglobulin E.

Two peptides, P123 and P124, representing amino acid sequences His 542-Lys 557 and Tyr 459-Arg 472, respectively, of the CH4 domain of rat IgE and predicted to be located on accessible regions of the protein were synthesized by a solid-phase procedure. Rabbits were immunized with the peptides conjugated to KLH and their antisera were tested for reactivity with free peptide and rat IgE by inhibition-ELISA. Each animal produced antibodies which reacted specifically with its immunizing peptide (titre greater than 1/62,500), but not with other synthetic peptides of similar chain-length and composition. Antisera directed against peptides P123 and P124 specifically bound purified rat IgE (IR 162) and IgE in whole myeloma serum (greater than 1/6400), but showed no reaction with normal rat serum proteins and only very low binding to purified human IgE. In addition the binding of anti-peptide sera to rat IgE could be completely inhibited with either homologous peptide or purified rat IgE, but not by other peptides or purified human IgE. Heating rat IgE for 1 hr at 56 degrees C enhanced its binding to anti-peptide antibodies by between 4- and 60-fold, but markedly reduced its reactivity with a rabbit anti-rat IgE (Fc) serum. These results suggest that antibodies directed against the synthetic peptides employed recognize and specifically bind to sites within the CH4 domain of rat IgE represented by their respective immunizing peptides. Furthermore, these antibodies are capable of detecting subtle alterations in structural conformation resulting from heating at 56 degrees C. Epitopes represented by peptides P123 and P124 may contribute to the heat-sensitive cytophilic region of rat IgE.

Analysis of the interaction between rat immunoglobulin E and rat mast cells using anti-peptide antibodies.

Polyclonal antisera with pre-determined specificities for a range of rat IgE epitopes were produced by immunizing rabbits with KLH-conjugates of five different synthetic peptides representing sequences 378-396, 414-428, 491-503, 522-535 and 560-571 in the CH3 and CH4 domains of rat IgE. Each rabbit elicited peptide-specific antibodies which were capable of binding affinity-purified rat IgE (IR162) (titres 1/1000-1/10,000) and IgE in rat immunocytoma serum (IR162) either immobilized on microtitre-plates or in free-solution as assessed by ELISA. Heating a solution of rat IgE at 56 degrees C for 1 hr, a treatment known to abolish the cytophilic activity of rat IgE and also induce irreversible conformational changes in the CH3 and CH4 domains, resulted in enhanced binding of the immunoglobulin to antibodies directed against IgE sequences represented by two of the synthetic peptides 414-428 and 491-503, but not to the three other peptides. The five anti-peptide sera together with two previously studied antisera specific for rat IgE sequences 459-472 and 542-557 were tested in functional assays designed to investigate the mode of interaction between rat IgE and its receptor on rat mast cells. Each anti-peptide serum was capable of inhibiting the binding of IgE to mast cells and furthermore, able to initiate the secretion of histamine from cells sensitized with rat IgE in an "anti-IgE"-induced manner. In view of the evidence implicating the CH3 and/or CH4 domains as the location of the mast cell receptor-site on rat IgE, we propose a model to describe the mode of interaction between IgE and its mast cell receptor.

In vitro degradation of a PHB/PHV copolymer and a new technique for monitoring early surface changes.

The use of polyhydroxbutyrate and its copolymers as degradable materials for surgical use is showing increasing promise due to their long degradation profile. Of considerable interest were the interfacial changes and their role in affecting the overall or bulk degradation pattern. The role of pH and its effect on the degradation pattern were examined as polymer degradation significantly altered, depending on whether it was subjected to an alkaline or an acidic medium. In vitro surface changes were monitored using two techniques (scanning electron microscopy and goniophotometry); bulk changes were monitored by gravimetric, mechanical and molecular weight techniques. It was concluded that the bimodal molecular weight distribution plays a significant part in the degradation pattern and that this pattern is also considerably altered by pH.

Torsional moment to failure for carbon fibre polysulphone expandable rivets as compared with stainless steel screws for carbon fibre-reinforced epoxy fracture plate fixation.

A method of securing carbon fibre-reinforced epoxy bone plates with carbon fibre polysulphone expanding rivets was investigated. Six carbon fibre-reinforced epoxy bone plates were secured to rods with carbon fibre polysulphone rivets and six were secured with standard cortical stainless steel screws. These constructions were then subjected to pure torsional load to failure. The carbon fibre expandable rivets failed at a greater torsional moment.

Mechano-electrical properties of bone.

Bone has been shown to exhibit ferro-electric properties. The relationship between applied electric field and polarization shows a hysteresis character typical of this type of material. This implies a domain structure for the permanent dipoles present in bone. Attempts to demonstrate semi-conductor properties were unsuccessful although a change of electrical resistance with applied tensile strain was demonstrated. No effect on conductivity of bone with change of pH of the fluid in which it was immersed was shown and hence no confirmation of streaming potential effects was obtained.

The influence of anionic chitin derivatives on calcium phosphate crystallization.

The influence of two water-soluble anionic chitin derivatives, sodium carboxymethyl-chitin (CM-chitin) and phosphoryl-chitin (P-chitin) on the crystallization of calcium phosphate by seeded growth and turbidimetry were studied. The adsorption of these derivatives onto hydroxyapatite obtained at 37 degrees C, fitted the Langmuir isotherm. The affinity constant and number of adsorption sites were measured at 2.9 and 1.69 micromol m(-2) for CM-chitin and 11.85 and 4.23 micromol m(-2) for P-chitin. P-chitin exerted a potent inhibitory effect on the seeded growth of hydroxyapatite from a supersaturated solution, reducing the initial rate of crystallization by more than 90% at a solution concentration of 10(-4)M. Both chitin derivatives also retarded the rate of spontaneous calcium phosphate precipitation. The type of calcium phosphate precipitated was poorly crystallized, calcium-deficient apatite. The chitin derivatives were found to be incorporated into the precipitate and influenced both the phase and morphology of calcium phosphate formed.

Promotion of calcification on carboxymethylchitin discs.

A series of water-insoluble carboxymethylchitin (CM-chitin) discs of varying degrees of substitution (d.s.) has been investigated for their interaction with calcium phosphate. Discs of d.s. 0.03, 0.11, 0.14 and 0.23 were prepared by casting from solutions of CM-chitin in 90% formic acid. Calcium uptake and calcium phosphate nucleation were found to increase with the degree of substitution of the CM-chitin discs. The results suggest that water-insoluble CM-chitin may be useful as a platform for in vivo calcification.

Carbon fibre reinforced epoxy as a high strength, low modulus material for internal fixation plates.

A multi-axial carbon fibre/epoxy composite fracture plate has been developed. This type of plate appears to allow early consolidation of internally fixed fractures whilst avoiding the ensuing disadvantage of 'plate induced osteopoenia' which are observed with metal devices. The mechanical properties of these plates (determined 'in vitro') are reported, along with early results of implantation in sheep.

Development of a degradable composite for orthopaedic use: mechanical evaluation of an hydroxyapatite-polyhydroxybutyrate composite material.

This study evaluates the mechanical properties of a composite material comprising polyhydroxybutyrate with hydroxyapatite added in proportions varying from 0 to 50%. Among the three methods of production, injection moulding was found to result in the most satisfactory mechanical properties. The tensile and compressive strength and the modulus of elasticity of composite produced in this way fell within the range for fresh human bone from different anatomical sites. With the additional advantages of biocompatibility, biodegradability and the potential for piezoelectric stimulation of new local bone formation, it was concluded that the injection-moulded composite material has considerable potential for use in orthopaedic surgery, both as a material to construct certain orthopaedic implants and as an alternative to corticocancellous bone graft.