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Journal of Bacteriology  1961;82(5):706-713.
O'Connor, R. J. (University of Wisconsin, Madison), and Harlyn O. Halvorson. L-Alanine dehydrogenase: A mechanism controlling the specificity of amino acid-induced germination of Bacillus cereus spores. J. Bacteriol. 82:706–713. 1961.—A study has been undertaken of the properties and specificity of germination of spores of Bacillus cereus strain T. In the absence of additional carbon sources, only l-alanine, l-α-NH2-n-butyric acid, and l-cysteine were effective germinating agents. The physical properties of germination, induced by l-alanine and l-α-NH2-n-butyric acid following extended heat shock, were in close agreement with those of l-alanine dehydrogenase. The specificity of the germination system, as well as amino acid deamination in vivo, support the view that l-alanine dehydrogenase activity is essential for germination and that the enzyme serves as the initial binding site for l-alanine in heat-shocked spores.
PMCID: PMC279239  PMID: 14480841
2.  Prevalence of behaviors related to cigarette‐caused fires: a survey of Ontario smokers 
Injury Prevention  2007;13(4):237-242.
To identify the prevalence and correlates of behaviors related to the risk of cigarette‐caused fires.
Design and setting
Random‐digit‐dialed telephone survey in Ontario, Canada, July–September, 2005.
596 current cigarette smokers.
Outcome measures
Prevalence of fire‐risk events and behaviors such as burning clothing or objects in the home, leaving lit cigarettes unattended, dozing while smoking, and smoking in bed and correlates of these behaviors. Respondents were also asked if they ever worry about cigarette‐caused fires.
One in four smokers admitted to leaving lit cigarettes unattended in the last 30 days, while 15% admitted to smoking while in bed. Leaving lit cigarettes unattended was independent of demographic, socioeconomic or nicotine dependence indicators, but was related to worry about burning other persons with a cigarette (OR 1.72, 95% CI 1.04 to 2.85) and smoking inside the home (OR 2.98, 95% CI 1.66 to 5.35). Persons who were not white (OR 3.97, 95% CI 1.80 to 8.80), aged 18–24 years (OR 3.75, 95% CI 1.41 to 9.96), who had high nicotine dependence (OR 9.13, 95% CI 2.22 to 37.52) and worried about burning objects in their home (OR 2.43, 95% CI 1.31 to 4.52) were more likely to smoke in bed. 10 (1.7%) smokers reported having ever had a fire in their home started by a cigarette.
Smokers engage in behaviors such as smoking in bed and leaving lit cigarettes unattended that may place them at an increased risk of cigarette‐caused fires. As governments move to regulate cigarette ignition propensity, it is important to establish surveillance for behaviors related to fire risk.
PMCID: PMC2598319  PMID: 17686933
3.  Cigarette characteristic and emission variations across high-, middle- and low-income countries 
Public health  2010;124(12):667-674.
The public health burden of tobacco use is shifting to the developing world, and the tobacco industry may apply some of its successful marketing tactics, such as allaying health concerns with product modifications. This study used standard smoking machine tests to examine the extent to which the industry is introducing engineering features that reduce tar and nicotine to cigarettes sold in middle- and low-income countries.
Study design
Multicountry observational study.
Cigarettes from 10 different countries were purchased in 2005 and 2007 with low-, middle- and high-income countries identified using the World Bank’s per-capita gross national income metric. Physical measurements of each brand were tested, and tobacco moisture and weight, paper porosity, filter ventilation and pressure drop were analysed. Tar, nicotine and carbon monoxide emission levels were determined for each brand using International Organization for Standardization and Canadian Intensive methods. Statistical analyses were performed using Statistical Package for the Social Sciences.
Among cigarette brands with filters, more brands were ventilated in high-income countries compared with middle- and low-income countries [χ2(4)=25.92, P<0.001]. Low-income brands differed from high- and middle-income brands in engineering features such as filter density, ventilation and paper porosity, while tobacco weight and density measures separated the middle- and high-income groups. Smoke emissions differed across income groups, but these differences were largely negated when one accounted for design features.
This study showed that as a country’s income level increases, cigarettes become more highly engineered and the emissions levels decrease. In order to reduce the burden of tobacco-related disease and further effective product regulation, health officials must understand cigarette design and function within and between countries.
PMCID: PMC2998539  PMID: 21030055
Tobacco; Emissions; Regulation
4.  The reliability and predictive validity of the Heaviness of Smoking Index and its two components: Findings from the International Tobacco Control Four Country study 
Nicotine & Tobacco Research  2010;12(Suppl 1):S45-S50.
There is increasing recognition that the two measures in the Heaviness of Smoking Index (HSI), time to first cigarette of the day (TTFC) and daily consumption (cigarettes per day [CPD]), are strong predictors of quitting behavior.
Use of Waves 1–4 of International Tobacco Control cohort with around 8,000 respondents per wave and 6,000 for prediction of quit outcomes at the next wave. We measured TTFC and CPD at each wave and quit outcomes at the next wave. We also looked at the relative utility of the standard categorical scoring compared with a continuous score using the square root of CPD minus the natural log of TTFC in minutes.
We found considerable consistency of the measures across years with a small decrease as duration between measurements increased. For a 3-year gap, the correlations were .72 and .70 for the continuous and categorical composite HSI measures, respectively, and were at least .63 for the individual components. Both TTFC and CPD independently predicted maintenance of quit attempts (for at least 1 month) in each of the three wave-to-wave replications, and these effects were maintained when controlling for demographic factors. CPD also predicted making attempts consistently, but the results for TTFC was not consistently significant.
Both TTFC and CPD are fairly reliable over time and are important predictors of quitting. There are only small effects of mode of computing the scores, and the two items can be used either individually or combined as the HSI.
PMCID: PMC3307335  PMID: 20889480
5.  Maximum yields might improve public health—if filter vents were banned: a lesson from the history of vented filters 
Tobacco Control  2006;15(3):262-266.
Filter ventilation is the dominant design feature of the modern cigarette that determines yields of tar, nicotine, and carbon monoxide on smoking machine tests. The commercial use of filter ventilation was precipitated by the 1964 United States Surgeon‐General's report, further advanced by the adoption of an official Federal Trade Commission test in 1967, and still further advanced by the inclusion of a gas phase (carbon monoxide) measure in 1979. The first vented‐filter brand on the market in the United States (Carlton) in 1964 and the second major vented‐filter brand (True) in 1966 illustrate this. Ultimately, filter ventilation became a virtually required way to make very low tar cigarettes (less than 10 mg or, even more so, less than 5 mg tar). The key to the lower tar cigarette was not, in effect, the advanced selective filtration design characteristics or sophisticated tobacco selection or processing as envisioned by experts (although these techniques were and are used); the key to the very much lower tar cigarette was simply punching holes in the filter. We propose that the banning of filter vents, coupled with low maximum standard tar, nicotine, and carbon monoxide yields, would contribute to making cigarettes much less palatable and foster smoking cessation or the use of clearly less hazardous nicotine delivery systems. It may be necessary to link low maximum yields with the banning of filter ventilation to achieve public health benefit from such maxima.
PMCID: PMC2564672  PMID: 16728759
policy; cigarettes; ventilation; tar yields; compensation
6.  Individual‐level predictors of cessation behaviours among participants in the International Tobacco Control (ITC) Four Country Survey 
Tobacco Control  2006;15(Suppl 3):iii83-iii94.
The International Tobacco Control (ITC) Four Country Survey (ITC‐4) is a prospective cohort study designed to evaluate the psychosocial and behavioural impact of national‐level tobacco control policies enacted in the Australia, Canada, the UK, and the USA. Wave 1 of ITC‐4 survey was conducted between October 2002 and December 2002. Wave 2 survey was conducted between May 2003 and August 2003.
To test for individual‐level predictors of smoking cessation behaviours (that is, quit attempts and smoking cessation) among cigarette smokers in the ITC Four Country Study measured between Wave 1 and Wave 2. This set of predictors will serve as the base for evaluating the added effect of tobacco control policies and other factors.
Respondents included in this study are 6682 adult current smokers in the Wave 1 main survey who completed the Wave 2 follow‐up (1665 were in Canada, 1329 were in the USA, 1837 were in the UK and 1851 were in Australia).
Factors predictive of making a quit attempt included intention to quit, making a quit attempt in the previous year, longer duration of past quit attempts, less nicotine dependence, more negative attitudes about smoking, and younger age. Lower levels of nicotine dependence were the main factor that predicted future cessation among those that made a quit attempt.
Intention to quit and other cognitive variables were associated with quit attempts, but not cessation. Behavioural variables related to task difficulty, including measures of dependence, predicted both making attempts and their success. Predictors of making quit attempts and cessation were similar for each of the four countries, but there were some differences in predictors of success.
PMCID: PMC2593055  PMID: 16754952
cessation; cohort; international
7.  Smokers' reactions to reduced ignition propensity cigarettes 
Tobacco Control  2006;15(1):45-49.
On 28 June 2004, New York State (NY) became the first jurisdiction to require cigarettes to meet a reduced ignition propensity (RIP) standard. This law resulted in cigarette manufacturers modifying nearly all of their brands sold in NY. However, the same cigarette brands sold in other states were not modified to meet the RIP standard.
This paper examines relationships between the RIP law and smokers' awareness of changes in the performance of their cigarettes (that is, going out more frequently, change in taste), and smoking behaviour.
Data for this analysis come from a nationwide survey of 2088 adult smokers (> 18 years of age) conducted in the USA between July and December 2004. 143 of the smokers included in the survey were residents of NY while the remainder were from other states (n  =  1945). Survey participants were asked whether their cigarettes “ever go out between puffs” and whether they had noticed any change in the taste of their cigarettes in the past 12 months.
NY smokers were three times more likely than smokers in other states to report that their cigarettes often went out between puffs (17.3% v 5.6%). However, NY smokers appeared no more likely to report noticing differences in cigarette taste, an intention to quit smoking, or to have made quit attempts.
A significant minority of smokers in NY reported noticing changes in the performance of their cigarettes following the RIP law, as would be expected. However, the RIP law appears to have had no impact on the smoking habits of New Yorkers, countering arguments made by cigarette manufacturers that the law would impact consumer acceptability.
PMCID: PMC2563630  PMID: 16436405
fire‐safe; cigarettes; survey; consumer perceptions
8.  Beliefs about the relative harm of “light” and “low tar” cigarettes: findings from the International Tobacco Control (ITC) China Survey 
Tobacco Control  2010;19(Suppl_2):i54-i62.
Many smokers in Western countries perceive “light” or “low tar” cigarettes as less harmful and less addictive than “regular” or “full flavoured” cigarettes. However, there is little research on whether similar perceptions exist among smokers in low and middle incomes, including China.
To characterise beliefs about “light” and “low tar” cigarettes among adult urban smokers in China.
We analysed data from Wave 1 of the ITC China Survey, a face-to-face household survey of 4732 adult Chinese smokers randomly selected from six cities in China in 2006. Households were sampled using a stratified multistage design.
Half (50.0%) of smokers in our sample reported having ever tried a cigarette described as “light,” “mild” or “low tar”. The majority of smokers in our sample (71%) believed that “light” and/or “low tar” cigarettes are less harmful compared to “full flavoured” cigarettes. By far the strongest predictor of the belief that “light” and/or “low tar” cigarettes are less harmful was the belief that “light” and/or “low tar” cigarettes feel smoother on the respiratory system (p<0.001, OR=53.87, 95% CI 41.28 to 70.31).
Misperceptions about “light” and/or “low tar” cigarettes were strongly related to the belief that these cigarettes are smoother on the respiratory system. Future tobacco control policies should go beyond eliminating labelling and marketing that promotes “light” and “low tar” cigarettes by regulation of product characteristics (for example, additives, filter vents) that reinforce perceptions that “light” and “low tar” cigarettes are smoother on the respiratory system and therefore less harmful.
PMCID: PMC2976003  PMID: 20935197
9.  A cross-sectional study on levels of second-hand smoke in restaurants and bars in five cities in China 
Tobacco Control  2009;19(Suppl_2):i24-i29.
To assess indoor second-hand smoke (SHS) exposure in restaurants and bars via PM2.5 (fine particles 2.5 μm in diameter and smaller) level measurements in five cities in China.
The study was conducted from July to September in 2007 in Beijing, Xi'an, Wuhan, Kunming and Guiyang. Portable aerosol monitors were used to measure PM2.5 concentrations in 404 restaurants and bars. The occupant density and the active smoker density were calculated for each venue sampled.
Among the 404 surveyed venues, 23 had complete smoking bans, 9 had partial smoking bans and 313 (77.5%) were observed to have allowed smoking during sampling. The geometric mean of indoor PM2.5 levels in venues with smoking observed was 208 μg/m3 and 99 μg/m3 in venues without observed smoking. When outdoor PM2.5 levels were adjusted, indoor PM2.5 levels in venues with smoking observed were consistently significantly higher than in venues without smoking observed (F=80.49, p<0.001). Indoor PM2.5 levels were positively correlated with outdoor PM2.5 levels (partial rho=0.37 p<0.001) and active smoker density (partial rho=0.34, p<0.001).
Consistent with findings in other countries, PM2.5 levels in smoking places are significantly higher than those in smoke-free places and are strongly related to the number and density of active smokers. These findings document the high levels of SHS in hospitality venues in China and point to the urgent need for comprehensive smoke-free laws in China to protect the public from SHS hazards, as called for in Article 8 of the Framework Convention on Tobacco Control, which was ratified by China in 2005.
PMCID: PMC2976000  PMID: 20008154
10.  Relative Humidity and the Killing of Bacteria 
Applied Microbiology  1961;9(6):567-571.
The viability of washed moist cells of Serratia marcescens after storage has been measured in relation to variations in the prior treatment of the cells and in conditions of storage. The factors considered were: (i) water content during storage; (ii) method of arriving at water content (partial drying in vacuum or freeze-drying and addition of water); (iii) presence or absence of air during storage.
Increasingly rapid decay occurs as the water content at which the cells are stored is diminished from above 90% to 20 or 30% (“critical” water content). It occurs in presence or absence of air and it occurs whether the final water content is approached by removal of water from wet cells or by addition of water to freeze-dried cells.
The rate of decay during storage at 20 to 30% water is somewhat diminished by the presence of air (“protective” effect of air).
As the water content is further reduced to less than 10%, the stability of cells stored in a vacuum approaches that of wet cells. In presence of air the reverse is true: the stability decreases until at less than 1% water, the decay rate is about as great as at the “critical” water content (“toxic” effect of air).
Particularly rapid decay of S. marcescens at the “critical” water content has escaped attention in aerosol studies because accurate control of relative humidity (RH) in this region, RH 94 to 99%, is virtually impossible in such studies. On the other hand, values of decay rates referred to measured water contents are quite unreliable in the 20 to 80% RH zone because the corresponding variation of water content is too small to measure reliably. Thus data of the kind reported in this paper cannot be directly compared to the published results of studies of air-borne bacteria, although they are relevant to the practical question of air-borne infection in humid atmospheres.
PMCID: PMC1057789  PMID: 13865722
12.  Mutually exclusive interaction of the adenovirus E4-6/7 protein and the retinoblastoma gene product with internal domains of E2F-1 and DP-1. 
Journal of Virology  1994;68(11):6848-6862.
The binding of E2F to the adenovirus (Ad) E2a promoter is stimulated by the Ad E4-6/7 protein. E2F DNA binding activity is composed of a heterodimer of related but distinct proteins of the E2F-1 and DP-1 families. The E4-6/7 protein induces the cooperative and stable binding of E2F to an inverted repeat binding site in the E2a promoter apparently by providing a dimerization interface to two adjacent E2F heterodimers. The product of the retinoblastoma gene product (Rb) represses the transcriptional activity of E2F by direct protein-protein interaction. In this report, we have examined the regions of E2F-1 and DP-1 that are required for the induction of cooperative E2F binding to the E2a promoter by the E4-6/7 protein. Our results demonstrate that an internal segment of E2F-1, that is conserved among members of the E2F family, is required for functional interaction with the E4-6/7 product. Consistent with this observation, other members of the E2F family (E2F-2 and E2F-3) productively interact with E4-6/7. DP-1 also is necessary for stable interaction with E4-6/7 and an internal segment of DP-1 is required that is positioned in a location similar to that of the conserved E2F-1 domain. Interestingly, the binding of E4-6/7 and the binding of Rb to E2F are mutually exclusive, and our results show that the same internal segments of E2F-1 and DP-1 that are required for E4-6/7 binding are also required for stable interaction with Rb. These results suggest that the Ad E4-6/7 protein mimics Rb in part for the protein interaction requirements for E2F binding, although with different functional consequences. While Rb binding represses E2F activity, the E4-6/7 protein stimulates transactivation of the Ad E2a promoter.
PMCID: PMC237120  PMID: 7933066
13.  The adenovirus E4-6/7 protein transactivates the E2 promoter by inducing dimerization of a heteromeric E2F complex. 
Molecular and Cellular Biology  1994;14(2):1333-1346.
Binding of the mammalian transcription factor E2F to the adenovirus E2a early promoter is modulated through interaction with the viral E4-6/7 protein. E4-6/7 induces the cooperative and stable binding of E2F in vitro to two correctly spaced and inverted E2F binding sites in the E2a promoter (E2F induction) by physical interaction in the protein-DNA complex. The E2a promoter is transactivated in vivo by the E4-6/7 product. The C-terminal 70 amino acids of E4-6/7 are necessary and sufficient for induction of E2F binding and for transactivation. To assess the mechanism(s) of E2a transactivation and the induction of cooperative E2F binding by the E4-6/7 protein, we have analyzed a series of point mutants in the functional C-terminal domain of E4-6/7. Two distinct segments of E4-6/7 are required for interaction with E2F. Additionally, and E4-6/7 mutant with a phenylalanine-to-proline substitution at amino acid 125 (F-125-P) efficiently interacts with E2F but does not induce E2F binding to the E2a promoter and is defective for transactivation. Induction of E2F stable complex formation at the E2a promoter by the F-125-P mutant protein is restored by divalent E4-6/7-specific monoclonal antibodies, but not a monovalent Fab fragment, or by appending a heterologous dimerization domain to the N terminus of the mutant protein. These and other data support the involvement of E4-6/7 dimerization in the induction of cooperative and stable E2F binding and transactivation of the E2a promoter. We present evidence that at least two cellular components are involved in E2F DNA binding activity and that both are required for E2F induction by the E4-6/7 product. The recently cloned E2F-related activities E2F-1 and DP-1 individually bind to an E2F binding site weakly, but when combined generate an activity that is indistinguishable from endogenous cellular E2F. Recombinant E2F-1, DP-1, and E4-6/7 are sufficient to form the induced E2F complex at the E2a promoter.
PMCID: PMC358488  PMID: 8289811
14.  The C-terminal 70 amino acids of the adenovirus E4-ORF6/7 protein are essential and sufficient for E2F complex formation. 
Nucleic Acids Research  1991;19(23):6579-6586.
E2F is a cellular transcription factor that binds to the adenovirus (Ad) E1A enhancer and E2aE promoter regions, to the cellular c-myc P2 and dihydrofolate reductase promoters, and to other viral and cellular regulatory regions. The binding activity of E2F to the Ad E2aE promoter is dramatically increased during an adenovirus infection (termed E2F induction). E2F induction is dependent on the expression of the 150 amino acid E4-ORF6/7 protein which forms a direct, physical complex with E2F to mediate the cooperative and stable binding of E2F to inverted sites in the E2aE promoter. Using in vitro DNA binding assays to measure the formation of the infection-specific complexes, we have defined the minimal domain of the E4-ORF6/7 protein, the C-terminal 70 amino acids, required to complex with E2F and stabilize its binding at the E2aE promoter. The ability of mutant E4-ORF6/7 proteins to form the stable E2F-E2aE promoter complex in vitro correlated well with their ability to trans-activate E2 transcription in vivo. These observations support a model in which the E4-ORF6/7 protein binds to E2F to induce the cooperative binding of two E2F molecules to the E2aE promoter thereby activating E2 transcription.
PMCID: PMC329223  PMID: 1836562

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