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IntroductionThis study examined trajectories of tobacco dependence (TD) in relationship to changes in tobacco product use, and explored the effects of product-specific adding, switching, or discontinued use on dependence over time.MethodsData were analyzed from the first three waves from the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative, longitudinal study of adults and youth in the United States (U.S.). Data included 9556 Wave 1 (2013/2014) adult current established tobacco users aged 18 or older who completed all three interviews and had established use at ≥2 assessments. Mutually exclusive groups included: users of cigarettes only, e-cigarettes only, cigars only, hookah only, any smokeless only, cigarette + e-cigarette dual users, and other multiple product users. A validated 16-item scale assessed TD across product users.ResultsPeople who used e-cigarettes exclusively at Wave 1 had small increases in TD through Wave 3. Wave 1 multiple product users' TD decreased across waves. TD for all other Wave 1 user groups remained about the same. For Wave 1 cigarette only smokers, switching to another product was associated with lower levels of TD than smokers whose use stayed the same. Movement to no established use of any tobacco product was consistently associated with lower TD for all product users.ConclusionsExcept for Wave 1 e-cigarette only users (who experienced small increases in TD), TD among U.S. tobacco product users was stable over time, with daily users less likely to vary from baseline.ImplicationsThe level of TD among most U.S. tobacco users was stable over the first three waves of the PATH Study and trends in levels of TD were predominantly unrelated to changes in patterns of continued product use. Stable levels of TD suggest a population at persistent risk of health impacts from tobacco. Wave 1 e-cigarette users experienced small increases in levels of TD over time, perhaps due to increases in quantity or frequency of their e-cigarette use or increasing efficiency of nicotine delivery over time. more...

IntroductionThis study examined trajectories of tobacco dependence (TD) in relation to changes in tobacco product use and explored the effects of product-specific adding, switching, or discontinued use on dependence over time.Aims and methodsData were analyzed from the first three waves of the Population Assessment of Tobacco and Health (PATH) Study, a nationally representative, longitudinal study of adults and youth in the United States. Data included 9556 Wave 1 (2013/2014) adult current established tobacco users who completed all three interviews and had established use at ≥2 assessments. Groups included cigarettes-only users, e-cigarettes-only users, cigars-only users, hookah-only users, any smokeless-only users, cigarette + e-cigarette dual users, and multiple product users. A validated 16-item scale assessed TD across product users.ResultsWave 1 e-cigarette-only users' who maintained exclusive e-cigarette use increased levels of TD through Wave 3 as did those who added or switched to another product. Wave 1 multiple product users' TD decreased across waves. TD for all other Wave 1 user groups remained about the same. For Wave 1 cigarette-only smokers, switching to another product or moving to a pattern of no established use was associated with lower levels of TD than smokers whose use stayed the same. Movement to no established use of any tobacco product was consistently associated with lower TD for all other product users.ConclusionsExcept for Wave 1 e-cigarette-only users, TD among US tobacco product users was stable over time, with daily users less likely to vary from baseline.ImplicationsThe level of TD among most US tobacco users was stable over the first three waves of the PATH Study and trends in levels of TD were predominantly unrelated to changes in patterns of continued product use. Stable levels of TD suggest a population at persistent risk of health impacts from tobacco. Wave 1 e-cigarette users, including those maintaining exclusive e-cigarette use, experienced increasing levels of TD over time, perhaps because of increases in quantity or frequency of their e-cigarette product use or increasing efficiency of nicotine delivery over time. more...

PrcisIn the Thessaloniki Eye Study (TES) incidence phase population, frequent dietary salt intake was potentially associated with increased risk of open angle glaucoma in antihypertensive users.PurposeThe aim was to examine the association between dietary salt intake and glaucoma by antihypertensive use in the TES population.Materials and methodsThe study population included TES incidence phase participants. Dietary salt intake frequency was assessed by self-report. Outcomes included prevalence of any open angle glaucoma (OAG), primary open angle glaucoma (POAG), and pseudoexfoliation (PEX). Covariates included demographics, cardiovascular disease, migraines, diabetes, steroid use, smoking, history of cataract surgery, central corneal thickness, intraocular pressure, blood pressure, and antihypertensive use. Logistic regression was used to examine associations between frequency of salt intake and glaucoma, controlling for covariates and stratified by antihypertensive use.ResultsThe study included 1076 participants 80.5±4.4 years old, of whom 518 were female. There were 89/1076 (8.3%) participants with any OAG, 46/789 (5.8%) with POAG, and 287/1030 (27.9%) with PEX. In participants with antihypertensive use, frequent versus never salt intake was associated with increased risk of any OAG [adjusted odds ratio (aOR)=2.65, 95% confidence interval (CI)=1.12, 6.28; n=784] and POAG (aOR=3.59, 95% CI=1.16, 11.11; n=578) overall, and additionally in participants with diastolic blood pressure more...

BackgroundWe examined the association of non-cigarette tobacco use on chronic obstructive pulmonary disease (COPD) risk in the Population Assessment of Tobacco and Health (PATH) Study.MethodsThere were 13,752 participants ≥ 40 years with Wave 1 (W1) data for prevalence analyses, including 6945 adults without COPD for incidence analyses; W1-5 (2013-2019) data were analyzed. W1 tobacco use was modeled as 12 mutually-exclusive categories of past 30-day (P30D) single and polyuse, with two reference categories (current exclusive cigarette and never tobacco). Prevalence and incidence ratios of self-reported physician-diagnosed COPD were estimated using weighted multivariable Poisson regression.ResultsW1 mean (SE) age was 58.1(0.1) years; mean cigarette pack-years was similar for all categories involving cigarettes and exclusive use of e-cigarettes (all > 20), greater than exclusive cigar users ( more...

IntroductionThis study examined the predictive relationships between biomarkers of nicotine exposure and 16-item self-reported level of tobacco dependence (TD) and subsequent tobacco use outcomes.Aims and methodsThe Population Assessment of Tobacco and Health (PATH) Study surveyed adult current established tobacco users who provided urine biospecimens at Wave 1 (September 2013-December 2014) and completed the Wave 2 (October 2014-October 2015) interview (n = 6872). Mutually exclusive user groups at Wave 1 included: Cigarette Only, E-cigarette Only, Cigar Only, Hookah Only, Smokeless Tobacco Only, Cigarette Plus E-cigarette, multiple tobacco product users who smoked cigarettes, and multiple tobacco product users who did not smoke cigarettes. Total Nicotine Equivalents (TNE-2) and TD were measured at Wave 1. Approximate one-year outcomes included frequency/quantity used, quitting, and adding/switching to different tobacco products.ResultsFor Cigarette Only smokers and multiple tobacco product users who smoked cigarettes, higher TD and TNE-2 were associated with: a tendency to smoke more, smoking more frequently over time, decreased likelihood of switching away from cigarettes, and decreased probability of quitting after one year. For other product user groups, Wave 1 TD and/or TNE-2 were less consistently related to changes in quantity and frequency of product use, or for adding or switching products, but higher TNE-2 was more consistently predictive of decreased probability of quitting.ConclusionsSelf-reported TD and nicotine exposure assess common and independent aspects of dependence in relation to tobacco use behaviors for cigarette smokers. For other product user groups, nicotine exposure is a more consistent predictor of quitting than self-reported TD.ImplicationsThis study suggests that smoking cigarettes leads to the most coherent pattern of associations consistent with a syndrome of TD. Because cigarettes continue to be prevalent and harmful, efforts to decrease their use may be accelerated via conventional means (eg, smoking cessation interventions and treatments), but also perhaps by decreasing their dependence potential. The implications for noncombustible tobacco products are less clear as the stability of tobacco use patterns that include products such as e-cigarettes continue to evolve. TD, nicotine exposure measures, and consumption could be used in studies that attempt to understand and predict product-specific tobacco use behavioral outcomes. more...

IntroductionThis study examined in youth (12-17 years), young adults (18-24 years), and adults (25+ years): (1) the prevalence of the first menthol cigarette and menthol/mint cigar use among new tobacco users; (2) association between the first menthol/mint use, subsequent tobacco use, and nicotine dependence ~1 year later compared with the first non-menthol/mint use.Aims and methodsLongitudinal analysis of data from Waves 1 to 4 of the Population Assessment of Tobacco and Health (PATH) Study (2013-2017; 10 086 youth and 21 281 adults). Main outcome measures were past 12-month and past 30-day cigarette and cigar use, and nicotine dependence.ResultsYouth and young adult new cigarette users are more likely to smoke a menthol cigarette or indicate that they do not know the flavor compared with adults aged 25+. A greater proportion of adults aged 25+ first used menthol/mint-flavored cigars (13.4%) compared with youth (8.5%) and young adults (7.4%). Among young adults, first use of a menthol cigarette is associated with past 12-month use of cigarettes at the subsequent wave and first use of any menthol/mint-flavored cigars is associated with past 30-day use of these products at the subsequent wave in both youth and young adults. In youth and adults, there were no significant relationships between first use of a menthol/mint cigarette or cigar and nicotine dependence scores at a subsequent wave in multivariable analyses.ConclusionsThe first use of menthol/mint cigarettes and cigars is associated with subsequent cigarette and cigar use in young people aged 12-24.ImplicationsThis study examined the relationship between initiation with menthol cigarettes and menthol/mint cigars, subsequent tobacco use, and nicotine dependence in US youth, young adults, and adults who participated in Waves 1-4 of the Population Assessment of Tobacco and Health study. New use of menthol cigarettes was associated with greater past 12-month cigarette use in young adults and new use of menthol/mint-flavored cigars was associated with greater past 30-day cigar use in youth and young adults compared with non-menthol use. Initiation with menthol/mint cigarette and cigar products may lead to subsequent use of those products. more...

Background and aimsBuilding on published work1 establishing concurrent validity of a self-report tobacco dependence (TD) index among users of different tobacco products in Wave 1 (W1) of the Population Assessment of Tobacco and Health (PATH) Study, the current study examines prospective relationships with tobacco use behaviors to establish predictive validity of the TD index. Hypotheses suggested high levels of W1 TD would be associated with persistent tobacco use at Wave 2 (W2).ParticipantsA U.S. nationally representative sample of 32,320 adult W1 and W2 interviews focused on 11,615 W1 adults who were current established tobacco users and completed the W2 interview.FindingsHigher TD scores and greater changes in TD scores were associated with greater quantity and frequency of tobacco use at the W2 interview for Cigarette Only (n = 7068), Smokeless (smokeless or snus pouches) Only (n = 772), Cigarette plus E-Cigarette (n = 592), and Multiple Products (n = 1866) users, although not significantly so for E-Cigarette Only (n = 367), Cigar Only (traditional, cigarillo, or filtered) (n = 584), or Hookah Only (n = 366) users. Higher TD was associated with decreased odds of successful quitting for Cigarette and Multiple Product users. Higher TD was associated with increased odds of a quit attempt for those in the Hookah and Multiple Products user groups and was not associated with quit attempts or deceased odds of quit success among exclusive E-Cigarette, Cigar, Smokeless and Cigarette plus E-Cigarette users.ConclusionSupport for the predictive validity of the PATH Study measures of adult TD will enable regulatory investigations of TD across several tobacco products. more...

We present an adult woman with subcutaneous nodules without any signs or symptoms of rheumatoid arthritis. These nodules are believed to be pseudorheumatoid nodules, which are considered a deep form of granuloma annulare. This case is unique because these are typically found in children and have rarely been reported in adults. These nodules are typically asymptomatic and do not require treatment. However, attempts have been made to treat them with intralesional corticosteroids, cryotherapy, or excision. Owing to the fact that this is considered a deep form of granuloma annulare, they are sometimes treated similarly with a combination of monthly rifampin, ofloxacin, and minocycline. more...

BackgroundMore smokers report using e-cigarettes to help them quit than FDA-approved pharmacotherapy.ObjectiveTo assess the association of e-cigarettes with future abstinence from cigarette and tobacco use.DesignCohort study of US sample, with annual follow-up.ParticipantsUS adult (ages 18+) daily cigarette smokers identified at Wave 1 (W1; 2013-14) of the PATH Study, who reported a quit attempt before W2 and completed W3 (n = 2443).ExposuresUse of e-cigarettes, pharmacotherapy (including nicotine replacement therapy), or no product for last quit attempt (LQA), and current daily e-cigarette use at W2.AnalysisPropensity score matching (PSM) of groups using different methods to quit.Outcome measures12+ months abstinence at W3 from cigarettes and from all tobacco (including e-cigarettes). 30+ days abstinence at W3 was a secondary outcome.ResultsAmong daily smokers with an LQA, 23.5% used e-cigarettes, 19.3% used pharmacotherapy only (including NRT) and 57.2% used no product. Cigarette abstinence for 12+ months at W3 was ~10% in each group. Half of the cigarette abstainers in the e-cigarette group were using e-cigarettes at W3. Different methods to help quitting had statistically comparable 12+ month cigarette abstinence at W3 (e-cigarettes vs no product: Risk Difference (RD) = 0.01, 95% CI: -0.04 to 0.06; e-cigarettes vs pharmacotherapy: RD = 0.02, 95% CI:-0.04 to 0.09). Likewise, daily e-cigarette users at W2 did not show a cessation benefit over comparable no-e-cigarette users and this finding was robust to sensitivity analyses. Abstinence for 30+ days at W3 was also similar across products.LimitationsThe frequency of e-cigarette use during the LQA was not assessed, nor was it possible to assess continuous abstinence from the LQA.ConclusionAmong US daily smokers who quit cigarettes in 2014-15, use of e-cigarettes in that attempt compared to approved cessation aids or no products showed similar abstinence rates 1-2 years later. more...

BackgroundMore smokers report using e-cigarettes to help them quit than FDA-approved pharmacotherapy.ObjectiveTo assess the association of e-cigarettes with future abstinence from cigarette and tobacco use.DesignCohort study of US sample, with annual follow-up.ParticipantsUS adult (ages 18+) daily cigarette smokers identified at Wave 1 (W1; 2013-14) of the PATH Study, who reported a quit attempt before W2 and completed W3 (n = 2443).ExposuresUse of e-cigarettes, pharmacotherapy (including nicotine replacement therapy), or no product for last quit attempt (LQA), and current daily e-cigarette use at W2.AnalysisPropensity score matching (PSM) of groups using different methods to quit.Outcome measures12+ months abstinence at W3 from cigarettes and from all tobacco (including e-cigarettes). 30+ days abstinence at W3 was a secondary outcome.ResultsAmong daily smokers with an LQA, 23.5% used e-cigarettes, 19.3% used pharmacotherapy only (including NRT) and 57.2% used no product. Cigarette abstinence for 12+ months at W3 was ~10% in each group. Half of the cigarette abstainers in the e-cigarette group were using e-cigarettes at W3. Different methods to help quitting had statistically comparable 12+ month cigarette abstinence at W3 (e-cigarettes vs no product: Risk Difference (RD) = 0.01, 95% CI: -0.04 to 0.06; e-cigarettes vs pharmacotherapy: RD = 0.02, 95% CI:-0.04 to 0.09). Likewise, daily e-cigarette users at W2 did not show a cessation benefit over comparable no-e-cigarette users and this finding was robust to sensitivity analyses. Abstinence for 30+ days at W3 was also similar across products.LimitationsThe frequency of e-cigarette use during the LQA was not assessed, nor was it possible to assess continuous abstinence from the LQA.ConclusionAmong US daily smokers who quit cigarettes in 2014-15, use of e-cigarettes in that attempt compared to approved cessation aids or no products showed similar abstinence rates 1-2 years later. more...

More than half of adult tobacco users in the United States (U.S.) transitioned in tobacco product use between 2013⁻2014 and 2014⁻2015. We examine how characteristics of adult tobacco users in the U.S. relate to transitions in tobacco product use. Population Assessment of Tobacco and Health (PATH) Study data were analyzed from 12,862 adult current tobacco users who participated in Wave 1 (W1, 2013⁻2014) and Wave 2 (W2, 2014⁻2015). Three types of transitions were examined-(1) adding tobacco product(s); (2) switching to non-cigarette tobacco product(s); and (3) discontinuing all tobacco use-among those currently using: (1) any tobacco product; (2) cigarettes only (i.e., exclusive cigarette); and (3) cigarettes plus another tobacco product(s) (i.e., poly-cigarette). Multinomial logistic regression analyses determined relative risk of type of transition versus no transition as a function of demographic and tobacco use characteristics. Transitions in tobacco product use among adult tobacco users were common overall, but varied among different demographic groups, including by age, sex, sexual orientation, race/ethnicity, educational attainment, and poverty level. Further, cigarette smokers with higher dependence scores were more likely to add product(s) and less likely to discontinue tobacco use compared to those with low dependence scores. That high nicotine dependence is a barrier to discontinuing tobacco use adds evidence to support policy to lower nicotine content of cigarettes and to evaluate new products for their potential to reduce cigarette use. more...

In 2013⁻2014, nearly 28% of adults in the United States (U.S.) were current tobacco users with cigarettes the most common product used and with nearly 40% of tobacco users using two or more tobacco products. We describe overall change in prevalence of tobacco product use and within-person transitions in tobacco product use in the U.S. between 2013⁻2014 and 2014⁻2015 for young adults (18⁻24 years) and older adults (25+ years). Data from Wave 1 (W1, 2013⁻2014) and Wave 2 (W2, 2014⁻2015) of the Population Assessment of Tobacco and Health (PATH) Study were analyzed (N = 34,235). Tobacco product types were categorized into: (1) combustible (cigarettes, cigars, pipe tobacco, hookah), (2) noncombustible (smokeless tobacco, snus pouches, dissolvable tobacco), and (3) electronic nicotine delivery systems (ENDS). Transitions for individual combustible-product types, and for single- and multiple-product use, were also considered. Overall prevalence of current tobacco use decreased from 27.6% to 26.3%. Among W1 non-tobacco users, 88.7% of young adults and 95.8% of older adults were non-tobacco users at W2. Among W1 tobacco users, 71.7% of young adults transitioned, with 20.7% discontinuing use completely, and 45.9% of older adults transitioned, with 12.5% discontinuing use completely. Continuing with/transitioning toward combustible product(s), particularly cigarettes, was more common than continuing with/transitioning toward ENDS. Tobacco use behaviors were less stable among young adults than older adults, likely reflecting greater product experimentation among young adults. Relative stability of cigarette use compared to other tobacco products (except older adult noncombustible use) demonstrates high abuse liability for cigarettes. more...

In 2013⁻2014, nearly 28% of adults in the United States (U.S.) were current tobacco users with cigarettes the most common product used and with nearly 40% of tobacco users using two or more tobacco products. We describe overall change in prevalence of tobacco product use and within-person transitions in tobacco product use in the U.S. between 2013⁻2014 and 2014⁻2015 for young adults (18⁻24 years) and older adults (25+ years). Data from Wave 1 (W1, 2013⁻2014) and Wave 2 (W2, 2014⁻2015) of the Population Assessment of Tobacco and Health (PATH) Study were analyzed (N = 34,235). Tobacco product types were categorized into: (1) combustible (cigarettes, cigars, pipe tobacco, hookah), (2) noncombustible (smokeless tobacco, snus pouches, dissolvable tobacco), and (3) electronic nicotine delivery systems (ENDS). Transitions for individual combustible-product types, and for single- and multiple-product use, were also considered. Overall prevalence of current tobacco use decreased from 27.6% to 26.3%. Among W1 non-tobacco users, 88.7% of young adults and 95.8% of older adults were non-tobacco users at W2. Among W1 tobacco users, 71.7% of young adults transitioned, with 20.7% discontinuing use completely, and 45.9% of older adults transitioned, with 12.5% discontinuing use completely. Continuing with/transitioning toward combustible product(s), particularly cigarettes, was more common than continuing with/transitioning toward ENDS. Tobacco use behaviors were less stable among young adults than older adults, likely reflecting greater product experimentation among young adults. Relative stability of cigarette use compared to other tobacco products (except older adult noncombustible use) demonstrates high abuse liability for cigarettes. more...

More than half of adult tobacco users in the United States (U.S.) transitioned in tobacco product use between 2013⁻2014 and 2014⁻2015. We examine how characteristics of adult tobacco users in the U.S. relate to transitions in tobacco product use. Population Assessment of Tobacco and Health (PATH) Study data were analyzed from 12,862 adult current tobacco users who participated in Wave 1 (W1, 2013⁻2014) and Wave 2 (W2, 2014⁻2015). Three types of transitions were examined-(1) adding tobacco product(s); (2) switching to non-cigarette tobacco product(s); and (3) discontinuing all tobacco use-among those currently using: (1) any tobacco product; (2) cigarettes only (i.e., exclusive cigarette); and (3) cigarettes plus another tobacco product(s) (i.e., poly-cigarette). Multinomial logistic regression analyses determined relative risk of type of transition versus no transition as a function of demographic and tobacco use characteristics. Transitions in tobacco product use among adult tobacco users were common overall, but varied among different demographic groups, including by age, sex, sexual orientation, race/ethnicity, educational attainment, and poverty level. Further, cigarette smokers with higher dependence scores were more likely to add product(s) and less likely to discontinue tobacco use compared to those with low dependence scores. That high nicotine dependence is a barrier to discontinuing tobacco use adds evidence to support policy to lower nicotine content of cigarettes and to evaluate new products for their potential to reduce cigarette use. more...

This article is a written version of the Presidential Address1 I gave at the annual meeting of the National Council on Measurement in Education (NCME) in April 2017. It is a call to NCME members (and others who read this, of course) to rebalance their focus so that classroom assessments are seen as being at least as important as large-scale assessments for education (in fact, in my view, they are more important). The article reviews research literature about the effects of classroom assessment to establish its importance for education. Then, the roles of large-scale assessment are reviewed, and, in particular, it is noted how these can have negative results when the large-scale assessments are not well aligned with sound curriculum and instructional and assessment practices grounded in theories of learning. In the next two sections (a) the idea of a learning progression is described as a way to facilitate the coherence between classroom and large-scale assessment and (b) the idea of a “roadmap” is described, being the assessment components of the learning progression. This is followed by a description of an example of such a roadmap, developed for the Assessing Data Modeling and Statistical Reasoning project using the BEAR Assessment System (BAS). Finally, a concluding discussion reviews the ways that the coherence between large-scale and classroom assessments can be achieved using the BAS, and hence make measurement more important for education. more...

Item explanatory models have the potential to provide insight into why certain items are easier or more difficult than others. Through the selection of pertinent item features, one can gather validity evidence for the assessment if construct-related item characteristics are chosen. This is especially important when designing assessment tasks that address new standards. Using data from the Learning Progressions in Middle School Science Instruction and Assessment (LPS) project, this paper adopts an “item explanatory” approach and investigates whether certain item features can explain differences in item difficulties by applying an extension of the linear logistic test model. Specifically, this paper explores the effects of five features on item difficulty: type (argumentation, content, embedded content), scenario-based context, format (multiple-choice or open-ended), graphics, and academic vocabulary. Interactions between some of these features were also investigated. With the exception of context, all features had a statistically significant effect on difficulty. more...

Background and aimsWith no established standard for assessing tobacco dependence (TD) across tobacco products in surveys, the Population Assessment of Tobacco and Health (PATH) Study provides a unique platform for examining the psychometric properties and validity of multiple indicators of tobacco dependence across a range of tobacco products.ParticipantsA U.S. nationally representative sample from the 32,320 adult Wave 1 interviews with analyses focused on 14,287 respondents who were current established users of tobacco products.FindingsThis analysis confirms a single primary latent construct underlying responses to TD indicators for cigarettes, e-cigarettes, cigars, hookah, and smokeless tobacco products. Mutually exclusive past year tobacco-user groups included: cigarette only (n=8689), e-cigarette only (n=437), cigar only (traditional, cigarillo, or filtered) (n=706), hookah only (n=461), smokeless tobacco only (n=971), cigarette plus e-cigarette (n=709), and multiple tobacco product users (n=2314). Differential Item Functioning (DIF) analyses supported use of 16 of the 24 examined TD indicators for comparisons across tobacco users. With cigarette users as a reference (mean=0.0, SD=1.0), we observed a range of TD with hookah (mean=-1.71) and cigar (mean=-1.92) only users being the lowest, and cigarette plus e-cigarette product users being the highest (mean=0.35). Regression models including sociodemographic factors supported concurrent validity with increased product use frequency and TD among cigarette-only (p more...

Background and aimsWith no established standard for assessing tobacco dependence (TD) across tobacco products in surveys, the Population Assessment of Tobacco and Health (PATH) Study provides a unique platform for examining the psychometric properties and validity of multiple indicators of tobacco dependence across a range of tobacco products.ParticipantsA U.S. nationally representative sample from the 32,320 adult Wave 1 interviews with analyses focused on 14,287 respondents who were current established users of tobacco products.FindingsThis analysis confirms a single primary latent construct underlying responses to TD indicators for cigarettes, e-cigarettes, cigars, hookah, and smokeless tobacco products. Mutually exclusive past year tobacco-user groups included: cigarette only (n=8689), e-cigarette only (n=437), cigar only (traditional, cigarillo, or filtered) (n=706), hookah only (n=461), smokeless tobacco only (n=971), cigarette plus e-cigarette (n=709), and multiple tobacco product users (n=2314). Differential Item Functioning (DIF) analyses supported use of 16 of the 24 examined TD indicators for comparisons across tobacco users. With cigarette users as a reference (mean=0.0, SD=1.0), we observed a range of TD with hookah (mean=-1.71) and cigar (mean=-1.92) only users being the lowest, and cigarette plus e-cigarette product users being the highest (mean=0.35). Regression models including sociodemographic factors supported concurrent validity with increased product use frequency and TD among cigarette-only (p more...

BackgroundThis paper describes the methods and conceptual framework for Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study data collection. The National Institutes of Health, through the National Institute on Drug Abuse, is partnering with the Food and Drug Administration's (FDA) Center for Tobacco Products to conduct the PATH Study under a contract with Westat.MethodsThe PATH Study is a nationally representative, longitudinal cohort study of 45 971 adults and youth in the USA, aged 12 years and older. Wave 1 was conducted from 12 September 2013 to 15 December 2014 using Audio Computer-Assisted Self-Interviewing to collect information on tobacco-use patterns, risk perceptions and attitudes towards current and newly emerging tobacco products, tobacco initiation, cessation, relapse behaviours and health outcomes. The PATH Study's design allows for the longitudinal assessment of patterns of use of a spectrum of tobacco products, including initiation, cessation, relapse and transitions between products, as well as factors associated with use patterns. Additionally, the PATH Study collects biospecimens from consenting adults aged 18 years and older and measures biomarkers of exposure and potential harm related to tobacco use.ConclusionsThe cumulative, population-based data generated over time by the PATH Study will contribute to the evidence base to inform FDA's regulatory mission under the Family Smoking Prevention and Tobacco Control Act and efforts to reduce the Nation's burden of tobacco-related death and disease. more...

BackgroundThis paper describes the methods and conceptual framework for Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study data collection. The National Institutes of Health, through the National Institute on Drug Abuse, is partnering with the Food and Drug Administration's (FDA) Center for Tobacco Products to conduct the PATH Study under a contract with Westat.MethodsThe PATH Study is a nationally representative, longitudinal cohort study of 45 971 adults and youth in the USA, aged 12 years and older. Wave 1 was conducted from 12 September 2013 to 15 December 2014 using Audio Computer-Assisted Self-Interviewing to collect information on tobacco-use patterns, risk perceptions and attitudes towards current and newly emerging tobacco products, tobacco initiation, cessation, relapse behaviours and health outcomes. The PATH Study's design allows for the longitudinal assessment of patterns of use of a spectrum of tobacco products, including initiation, cessation, relapse and transitions between products, as well as factors associated with use patterns. Additionally, the PATH Study collects biospecimens from consenting adults aged 18 years and older and measures biomarkers of exposure and potential harm related to tobacco use.ConclusionsThe cumulative, population-based data generated over time by the PATH Study will contribute to the evidence base to inform FDA's regulatory mission under the Family Smoking Prevention and Tobacco Control Act and efforts to reduce the Nation's burden of tobacco-related death and disease. more...

Measurement has played a central role in the development of the physical sciences and engineering, and is considered by many to be a privileged method for acquiring information about the world. It is thus unsurprising that the psychological sciences have also attempted to develop methods for measurement. However, it is not clear how the ways in which psychological scientists understand measurement accord with how the concept is understood in other scientific disciplines, or by the professional and general publics. In part this may be due to the ways in which several distinct strands of thinking about scientific inquiry (and measurement in particular) have influenced the work of psychological scientists over roughly the past hundred years. Given that such influences are often not studied or even acknowledged, many psychological scientists may be unaware of the resulting tensions in their conceptual vocabulary, and of the gaps between the nature of their claims on psychological measurement and the substantiation for those claims. The aim of this paper is to overview the major philosophical influences on thinking about psychological measurement, and to note the pitfalls of some of the extreme positions that have emerged. We hope that such an overview may help facilitate greater clarity concerning the semantics of measurement claims made by psychological scientists. more...

IntroductionConcurrent use of cigarettes and smokeless tobacco is common, but little is known regarding the association of smokeless tobacco use with cigarette smoking cessation. Dual users may have lower cigarette consumption levels, which may also play a role in smoking cessation.MethodsThe 2010–2011 Tobacco Use Supplement to the Current Population Survey included 26,760 current cigarette smokers, of which 675 concurrently used smokeless tobacco. We compared characteristics of the most recent cigarette smoking quit attempt of the past year between dual users and exclusive smokers, using multivariate regression.ResultsDual users (45%) were more likely than exclusive smokers (37%) to have made a cigarette smoking quit attempt during the previous year (p more...

BackgroundNicotine dependence (ND) is a key construct that organizes physiological and behavioral symptoms associated with persistent nicotine intake. Measurement of ND has focused primarily on cigarette smokers. Thus, validation of brief instruments that apply to a broad spectrum of tobacco product users is needed.MethodsWe examined multiple domains of ND in a longitudinal national study of the United States population, the United States National Epidemiological Survey of Alcohol and Related Conditions (NESARC). We used methods based in item response theory to identify and validate increasingly brief measures of ND that included symptoms to assess ND similarly among cigarette, cigar, smokeless, and poly tobacco users.ResultsConfirmatory factor analytic models supported a single, primary dimension underlying symptoms of ND across tobacco use groups. Differential Item Functioning (DIF) analysis generated little support for systematic differences in response to symptoms of ND across tobacco use groups. We established significant concurrent and predictive validity of brief 3- and 5- symptom indices for measuring ND.ConclusionsMeasuring ND across tobacco use groups with a common set of symptoms facilitates evaluation of tobacco use in an evolving marketplace of tobacco and nicotine products. more...

PurposeTo investigate the association of the two single-nucleotide polymorphisms (SNPs) in the lysyl oxidase-like 1 (LOXL1) gene with pseudoexfoliation syndrome (PEX), pseudoexfoliative glaucoma (PEXG), and primary open-angle glaucoma (POAG) in a Greek population-based setting, from the Thessaloniki Eye study.MethodsA total of 233 subjects with successful DNA extraction, PCR amplification, and genotyping were included in the genetic analysis of G153D and R141L SNPs of LOXL1 gene and classified into four groups: controls (n = 93); subjects with PEX (n = 40); POAG (n = 66); and PEXG (n = 34). Multinomial logistic regression was used to test their association with LOXL1 SNPs with adjustment for covariates. The association of LOXL1 with IOP (in untreated subjects) and with systemic diseases was explored.ResultsBoth LOXL1 SNPs were present in high frequencies in controls and cases. The G153D was strongly associated with both PEX (odds ratio [OR] = 23.2, P = 0.003 for allele G) and PEXG (OR = 24.75, P = 0.003 for allele G) and was not associated with POAG (P = 0.451). In contrast, the R141L was not associated with PEX (P = 0.81), PEXG (P = 0.063), or POAG (P = 0.113). No association of the G153D with either intraocular pressure (IOP) or systemic diseases was found.ConclusionsIn the Thessaloniki Eye Study, the G153D SNP of LOXL1 gene was strongly associated with both PEX and PEXG, whereas the R141L was not associated. No association of the LOXL1 with IOP or with systemic diseases was found. These findings further support the hypothesis that the LOXL1 gene contributes to onset of PEXG through PEX. Gene variants of LOXL1 do not help to identify those with PEX at increased risk for glaucoma development. more...

PurposeTo investigate the association of the two single-nucleotide polymorphisms (SNPs) in the lysyl oxidase-like 1 (LOXL1) gene with pseudoexfoliation syndrome (PEX), pseudoexfoliative glaucoma (PEXG), and primary open-angle glaucoma (POAG) in a Greek population-based setting, from the Thessaloniki Eye study.MethodsA total of 233 subjects with successful DNA extraction, PCR amplification, and genotyping were included in the genetic analysis of G153D and R141L SNPs of LOXL1 gene and classified into four groups: controls (n = 93); subjects with PEX (n = 40); POAG (n = 66); and PEXG (n = 34). Multinomial logistic regression was used to test their association with LOXL1 SNPs with adjustment for covariates. The association of LOXL1 with IOP (in untreated subjects) and with systemic diseases was explored.ResultsBoth LOXL1 SNPs were present in high frequencies in controls and cases. The G153D was strongly associated with both PEX (odds ratio [OR] = 23.2, P = 0.003 for allele G) and PEXG (OR = 24.75, P = 0.003 for allele G) and was not associated with POAG (P = 0.451). In contrast, the R141L was not associated with PEX (P = 0.81), PEXG (P = 0.063), or POAG (P = 0.113). No association of the G153D with either intraocular pressure (IOP) or systemic diseases was found.ConclusionsIn the Thessaloniki Eye Study, the G153D SNP of LOXL1 gene was strongly associated with both PEX and PEXG, whereas the R141L was not associated. No association of the LOXL1 with IOP or with systemic diseases was found. These findings further support the hypothesis that the LOXL1 gene contributes to onset of PEXG through PEX. Gene variants of LOXL1 do not help to identify those with PEX at increased risk for glaucoma development. more...

Since DSM-IV was published in 1994, its approach to substance use disorders has come under scrutiny. Strengths were identified (notably, reliability and validity of dependence), but concerns have also arisen. The DSM-5 Substance-Related Disorders Work Group considered these issues and recommended revisions for DSM-5. General concerns included whether to retain the division into two main disorders (dependence and abuse), whether substance use disorder criteria should be added or removed, and whether an appropriate substance use disorder severity indicator could be identified. Specific issues included possible addition of withdrawal syndromes for several substances, alignment of nicotine criteria with those for other substances, addition of biomarkers, and inclusion of nonsubstance, behavioral addictions.This article presents the major issues and evidence considered by the work group, which included literature reviews and extensive new data analyses. The work group recommendations for DSM-5 revisions included combining abuse and dependence criteria into a single substance use disorder based on consistent findings from over 200,000 study participants, dropping legal problems and adding craving as criteria, adding cannabis and caffeine withdrawal syndromes, aligning tobacco use disorder criteria with other substance use disorders, and moving gambling disorders to the chapter formerly reserved for substance-related disorders. The proposed changes overcome many problems, while further studies will be needed to address issues for which less data were available. more...

Since DSM-IV was published in 1994, its approach to substance use disorders has come under scrutiny. Strengths were identified (notably, reliability and validity of dependence), but concerns have also arisen. The DSM-5 Substance-Related Disorders Work Group considered these issues and recommended revisions for DSM-5. General concerns included whether to retain the division into two main disorders (dependence and abuse), whether substance use disorder criteria should be added or removed, and whether an appropriate substance use disorder severity indicator could be identified. Specific issues included possible addition of withdrawal syndromes for several substances, alignment of nicotine criteria with those for other substances, addition of biomarkers, and inclusion of nonsubstance, behavioral addictions.This article presents the major issues and evidence considered by the work group, which included literature reviews and extensive new data analyses. The work group recommendations for DSM-5 revisions included combining abuse and dependence criteria into a single substance use disorder based on consistent findings from over 200,000 study participants, dropping legal problems and adding craving as criteria, adding cannabis and caffeine withdrawal syndromes, aligning tobacco use disorder criteria with other substance use disorders, and moving gambling disorders to the chapter formerly reserved for substance-related disorders. The proposed changes overcome many problems, while further studies will be needed to address issues for which less data were available. more...

The function of human geophagy has long been questioned. We sought to test hypotheses concerning its potential physiological effects through analysis of soils and patterns in geophagy behavior. Eleven samples of geophagic soils consumed by pregnant women on Pemba Island, Zanzibar, Tanzania, were characterized according to their color, texture, major element chemistry, trace element chemistry, bulk mineralogy, and clay mineralogy. An epidemiological study (N = 2367) and ethnographic interviews (N = 57) on Pemba yielded information about geophagic behaviors and socio-demographic and biological characteristics of those who consumed earth. The soils varied widely in color, ranging from light red to white through various shades of brown and yellow, and texture ranged from clay to sand. Major element chemistry of the soils also varied greatly; most were low in Fe and Ca. Trace elements, whether of biological or non-biological significance, were uniformly low when compared with normal ranges of mineral soils. The sole commonality among the samples is that all clay fractions were dominated by a kaolin mineral: kaolinite, halloysite, or a mixture of both. Geophagy behavior also varied greatly, with one major exception: a greater proportion of pregnant women (7.1%) and young children (4.5%) consumed earth than non-pregnant women (0.2%) or men (0%). The presence of kaolin mineral in all samples, its palliative and detoxifying properties, and the highest prevalence of geophagy among those most biologically vulnerable suggest that geophagy may be a protective behavior. more...

The BABAR Silicon Vertex Tracker (SVT) has been efficiently operated for six years since the start of data taking in 1999. Due to higher than expected background levels some unforeseen effects have appeared. We discuss: a shift in the pedestal for the channels of the AToM readout chips that are most exposed to radiation; an anomalous increase in the bias leakage current for the modules in the outer layers. Estimates of future radiation doses and occupancies are shown together with the extrapolated detector performance and lifetime, in light of the new observations. (c) 2006 Elsevier B.V. All rights reserved. more...

IntroductionAlthough cataract surgery has been demonstrated to be effective and cost-effective, 5% to 20% of patients do not benefit functionally from the procedure. This study examines the cost-effectiveness of cataract surgery versus watchful waiting in a subgroup of patients who had less than a 30% predicted probability of reporting improvements in visual function after surgery.MethodsRandomized trial (first eye surgery vs. watchful waiting) of 250 patients who based on a cataract surgery index (CSI) were felt to have less than a 30% probability of reporting improvements in visual functioning after surgery. Cost was estimated using monthly resource utilization surveys and Medicare billing and payment data. Effectiveness was evaluated at 6 months using the Activities of Daily Vision Scale (ADVS) and the Health Utilities Index, Mark 3 (HUI3).ResultsIn terms of overall utility, the incremental cost-effectiveness of surgery was Dollars 38,288/QALY. In the subgroup of patients with a CSI score > 11 (< 20% probability of improvement), the cost-effectiveness of cataract surgery was Dollars 53,500/QALY. Sensitivity analysis demonstrated that often this population of patients may not derive a utility benefit with surgery.ConclusionCataract surgery is cost-effective even in a subpopulation of patient with a lower, < 30%, predicted probability of reporting improved visual functioning after surgery. There may be a subgroup of patients, CSI > 11, for whom a strategy of watchful waiting may be equally effective and considerably less expensive. more...

IntroductionAlthough cataract surgery has been demonstrated to be effective and cost-effective, 5% to 20% of patients do not benefit functionally from the procedure. This study examines the cost-effectiveness of cataract surgery versus watchful waiting in a subgroup of patients who had less than a 30% predicted probability of reporting improvements in visual function after surgery.MethodsRandomized trial (first eye surgery vs. watchful waiting) of 250 patients who based on a cataract surgery index (CSI) were felt to have less than a 30% probability of reporting improvements in visual functioning after surgery. Cost was estimated using monthly resource utilization surveys and Medicare billing and payment data. Effectiveness was evaluated at 6 months using the Activities of Daily Vision Scale (ADVS) and the Health Utilities Index, Mark 3 (HUI3).ResultsIn terms of overall utility, the incremental cost-effectiveness of surgery was Dollars 38,288/QALY. In the subgroup of patients with a CSI score > 11 (< 20% probability of improvement), the cost-effectiveness of cataract surgery was Dollars 53,500/QALY. Sensitivity analysis demonstrated that often this population of patients may not derive a utility benefit with surgery.ConclusionCataract surgery is cost-effective even in a subpopulation of patient with a lower, < 30%, predicted probability of reporting improved visual functioning after surgery. There may be a subgroup of patients, CSI > 11, for whom a strategy of watchful waiting may be equally effective and considerably less expensive. more...

To investigate the role of the Sry/hydroxymethylglutaryl box (Sox) transcription factors in the development of the pancreas, we determined the expression pattern of Sox factors in the developing mouse pancreas. By RT-PCR, we detected the presence of multiple Sox family members in both the developing pancreas and mature islets and then focused on two factors, Sox2 and Sox4. The expression field of Sox2, which plays a role in the maintenance of some stem cell populations, included the developing duodenum, but Sox2 was specifically excluded from the pancreatic buds. In contrast, Sox4 was detected broadly in the early pancreatic buds and eventually became restricted to the nuclei of all islet cells in the adult mouse. Mice homozygous for a null mutation of the sox4 gene showed normal pancreatic bud formation and endocrine cell differeniiation up to embryonic day 12.5. Beyond that date, cultured pancreatic explants lacking sox4 failed to form normal islets. Instead, a markedly reduced number of endocrine cells were found scattered through the explant. We show here that several Sox transcription factors are expressed in the developing pancreas and in the islet, and that one of these factors, Sox4, is required for the normal development of pancreatic islets. more...

Individual blood vessels in the chick choriallantoic membrane were selectively coagulated through photothermolysis, using pulsed laser irradiation at 585 nm. Pulse durations were chosen to be 0.45 ms and 10 ms, which correspond to the thermal relaxation times in blood vessels of 30 microns and 150 microns diameter, respectively. The short pulses, at a light fluence F = 3 Jcm-2, caused permanent occlusion of vessels of 40 microns diameter or less, whereas larger caliber vessels (60-120 microns) required F = 4-5 Jcm-2. The long-duration pulses, at F = 7 Jcm-2, caused coagulation of the larger diameter vessels; the small-caliber vessels and capillaries showed resistance to photothermolysis and required multiple exposures to achieve coagulation. The fluence versus diameter (F versus d) relationship for coagulation was calculated for the two pulse durations. The energy deposited in a cylindrical absorber of diameter d by an optical field, incident perpendicular to the vessel, was expressed analytically and compared with the energy required to coagulate a blood vessel of the same lumen dimeter. When thermal diffusion is incorporated into the model, our findings can be accounted for quantitatively. This information will be of use for improving the laser treatment of port wine stains and other vasculopathies. A surprising observation was that arterioles were damaged at lower incident energy densities than venules having the same lumen diameter, despite the fact that absorbance in oxygen-rich and oxygen-poor blood is the same at 585 nm. more...

Individual blood vessels in the chick chorioallantoic membrane (CAM) were selectively coagulated through photothermolysis, using pulsed laser irradiation at 585 nm. Pulse durations were chosen to be 0.45 ms and 10 ms, which correspond to the thermal relaxation times in blood vessels of 30 μm and 150 μm diameter, respectively. The short pulses, at an energy density (or light dose) D=3 Jcm-2, caused permanent occlusion of vessels of 40 μm diameter or less, while larger caliber vessels (60-120 p.m) required D=4-5 Jcm-2. The long-duration pulses, at D=7 Jcm-2, caused coagulation of the larger diameter vessels; the small caliber vessels and capillaries showed resistance to photothermolysis and required multiple exposures to achieve coagulation. The dose vs diameter (D vs d) relationship for coagulation was calculated for the two pulse shapes. The energy deposited in a cylindrical absorber of diameter d by an optical field, incident perpendicular to the vessel, was expressed analytically and compared with the energy required to coagulate a blood vessel of the same lumen diameter. When thermal diffusion is incorporated into the model, our findings can be accounted for quantitatively. This information will be of use for improving the laser treatment of port wine stains and other vasculopathies. A surprising observation was that arterioles were damaged at lower incident energy densities than venules having the same lumen diameter, despite the fact that absorbance in oxygen-rich and oxygen-poor blood is the same for 585 nm radiation. more...

Open laser endarterectomy produces a smooth arterial surface with welded distal end points. This report evaluates 308-nm excimer laser radiation for the laser endarterectomy operation. Arteriosclerotic New Zealand white rabbits (N = 15) were studied. A thoraco-abdominal exploration was performed, the aorta was isolated, heparin was administered, and multiple endarterectomies were performed in each rabbit. A line of laser craters was created at the proximal and distal ends of an atheroma. Laser radiation was used to connect the craters to form the proximal and distal end points. The atheromas were dissected from the aorta with laser light and the end points were fused. The aortas were removed for light and electron microscopy and the animals were sacrificed. Excimer radiation was delivered by a 600-microns fiber at 50 mJ/pulse, 120-ns pulses and either 15- or 20-Hz frequency. At 15 Hz excimer laser endarterectomies showed no perforations along the surface or at the end points. The surfaces were smooth but the end points were not welded in place. At 20 Hz, perforations were seen along 7/11 surfaces and at 5/11 end points. Excimer laser endarterectomy is best performed at 15 Hz. The end points, however, cannot be welded with excimer laser radiation. more...

Free beam laser endarterectomy (LE) and contact laser endarterectomy (CLE) were compared in 15 arteriosclerotic New Zealand white rabbits. The rabbits underwent balloon catheter trauma to the thoracoabdominal aorta and were fed a 2% cholesterol diet for 18 weeks. Thoracoabdominal exploration was performed under general anesthesia and multiple endarterectomies were performed in each rabbit. Atheromas were dissected from arteries with laser radiation and end points were welded in place with laser radiation. LEs (N = 8) were performed with argon ion radiation delivered through a 400 microns fiberoptic. Power was kept constant at 1 W and the average fluence was 97.5 +/- 6.6 J/cm2. CLEs were performed with conical sapphire probes powered by either argon ion radiation (N = 12) or Nd-YAG radiation (N = 10). Power used was 1 W to 4 W for each laser. Average argon ion fluence was 117.8 +/- 3.1 J/cm2 and average Nd-YAG fluence was 611.1 +/- 34.4 J/cm2. Following the operations, aortas were removed, fixed, serially sectioned, and stained. Microscopic study revealed welded end points with LE but not with CLE. There were no perforations with LE. There were 11/12 perforations with argon ion CLE and 8/10 perforations with Nd-YAG CLE. Free beam laser endarterectomy is superior to contact laser endarterectomy for experimental atheromas. more...

New applications of laser microbeam irradiation to cell and developmental biology include a new instrument with a tunable wavelength (217- to 800-nanometer) laser microbeam and a wide range of energies and exposure durations (down to 25 X 10(-12) second). Laser microbeams can be used for microirradiation of selected nucleolar genetic regions and for laser microdissection of mitotic and cytoplasmic organelles. They are also used to disrupt the developing neurosensory appendages of the cricket and the imaginal discs of Drosophila. more...

The surface thrombogenicity of atheromas, conventional endarterectomy (CE), laser endarterectomy (LE), and laser angioplasty (LA) were compared in the rabbit arteriosclerosis model. Normal (N = 6) and arteriosclerotic (N = 15) rabbits underwent thoracoabdominal exploration. Multiple CEs and LEs were performed in 12 arteriosclerotic rabbits leaving a segment of intact atheroma between each endarterectomy. Multiple LAs were performed in three arteriosclerotic rabbits. Argon ion laser radiation was used for all laser procedures. Blood (0.05 ml) from normal rabbits was placed on the CE surface, LE surface, LA surface, atheroma, and normal intima and clotting times were determined. Surface thrombogenicity was calculated as the ratio of the clotting time of the CE, LE, LA, or atheroma to normal intima. Surface thrombogenicity was 1.0 +/- 0.03 for normal intima (control), 0.58 +/- 0.06 for atheromas (P less than 0.001), 0.46 +/- 0.08 for CE (P less than 0.001 from atheromas), 0.46 +/- 0.08 for LE (P = NS from CE), and 0.27 +/- 0.09 for LA (P less than 0.001 from CE and LE). The thrombogenicity of LE is the same as the thrombogenicity of CE. Both forms of endarterectomy are less thrombogenic than LA in the rabbit model. more...

Arteriosclerotic arteries have been shown to fluoresce when treated with hematoporphyrin derivative. This study investigates the incorporation and distribution of a partially purified form of hematoporphyrin derivative (Photofrin II) in normal and arteriosclerotic rabbit aortas. A thoracoabdominal exploration was performed in 15 rabbits. Group I comprised normal rabbits, Group II normal rabbits given 5 mg/kg Photofrin II 48 hours before surgery, Group III arteriosclerotic rabbits and Group IV arteriosclerotic rabbits given 5 mg/kg Photofrin II 48 hours before surgery. Multiple aortic biopsy specimens for frozen section were taken from all rabbits. In addition, open laser endarterectomy (with an argon ion laser) was performed on Group III and Group IV rabbits. Frozen sections were studied by digital video fluorescence microscopy to determine the distribution of Photofrin II within the layers of the aortic wall. The fluorescence of the intima of Group IV rabbits was found to be significantly greater than that of the intima, internal elastic lamina, media or adventitia of the other groups (p less than 0.01) and significantly greater than that of the internal elastic lamina, media or adventitia of Group IV rabbits (p less than 0.01). When open laser endarterectomy was performed, Group III rabbits required 103 +/- 14 J/cm2 and Group IV required 33 +/- 3 J/cm2 (p less than 0.01). It is concluded that porphyrins are selectively localized within the intima of arteriosclerotic arteries. This localization sensitizes atheromas to argon ion laser light and facilitates laser endarterectomy. more...

Open laser endarterectomy was compared to standard surgical endarterectomy in the rabbit arteriosclerosis model. The aorta was exposed by a thoracoabdominal exploration in 16 rabbits. In Group I (8 rabbits), a conventional endarterectomy (CE) was performed with standard vascular instruments. In Group II (8 rabbits), laser endarterectomy (LE) was performed with an argon ion laser (488 nm and 514.5 nm) at a power of 1.0 W. Aortas were fixed, serially sectioned (6 micron) and stained (H +/- E) following each procedure. Gross and light microscopic examination revealed identical results for the endarterectomy surfaces of CE and LE. The proper cleavage plane within the media was developed with both techniques and the remaining arterial wall was not damaged with either procedure. The end points of LE were consistently superior to those of CE because of phototherapy fusion. The LE end points were tapered and the intima was fused. Intimal flaps were seen in 2/8 CE experiments and the remaining end points exhibited an uneven transition. LE required an average energy density of 124 +/- 9 J/cm2. We conclude that LE provides a satisfactory method for the in vivo evaluation of laser radiation upon arteriosclerotic arteries. LE may be the way to begin clinical laser trials. more...

New applications of laser microbeam irradiation to cell and developmental biology include a new instrument with a tunable wavelength (217- to 800-nanometer) laser microbeam and a wide range of energies and exposure durations (down to 25 X 10(-12) second). Laser microbeams can be used for microirradiation of selected nucleolar genetic regions and for laser microdissection of mitotic and cytoplasmic organelles. They are also used to disrupt the developing neurosensory appendages of the cricket and the imaginal discs of Drosophila. more...

An ultraviolet laser beam was focused to a submicron spot on one of the nucleolar organizer regions of mitotic chromosomes of rat kangaroo cells in tissue culture. The daughter cells were isolated and cloned into a viable population that maintained the directed nucleolar deficiency. It is concluded that the laser can be used to delete preselected genetic regions and the genetic deletion is maintained as a heritable deficiency in subsequent daughter cells. more...