Is exposure to pharmaceutical direct-to-consumer advertising for heart disease and diabetes associated with physical activity and dietary behavior?

CONTEXT

Scholars have suggested that direct-to-consumer advertising (DTCA) of prescription drugs may discourage or encourage changes in lifestyle to improve health. The current paper informs this debate by examining associations between estimated exposure to DTCA for drugs focused on heart disease/cholesterol and diabetes and self-reported exercise and consumption of a variety of unhealthy foods (candy, sugary drinks, alcohol, and fast food).

METHODS

We estimated exposure to DTCA by combining data from Kantar Media Intelligence (Kantar) on televised pharmaceutical DTCA airings in the U.S. from January 2003 to August 2016 (n = 7,696,851 airings) with thirteen years of data from the Simmons National Consumer Survey (Simmons), a mailed survey on television viewing patterns. We estimated associations between exposure to advertising (both overall and for advertisements with specific content) and self-reported physical activity and dietary behavior using Simmons data from January 2004 to December 2016 (n = 288,483 respondents from n = 157,621 unique households in the U.S.). Our analysis controls for many potential confounders including respondent demographics, temporal trends, and program placement to account for purposeful ad targeting to higher-risk adults.

FINDINGS

Higher estimated exposure to DTCA for heart disease and diabetes drugs were not consistently associated with meaningful differences in the frequency of engaging in regular physical activity. Greater estimated exposure to DTCA for both diseases were, linked to small but consistently higher volume of consumption of candy, sugar-sweetened beverages, alcohol, and fast food. Specific DTCA message content about diet and exercise explained very little of the observed association between overall DTCA exposure volume and study outcomes.

CONCLUSIONS

Many Americans were regularly exposed to pharmaceutical DTCA for heart disease and diabetes from 2003 to 2016. Widespread exposure to such DTCA is associated with higher levels (though small in magnitude) of consuming alcohol, fast food, candy, and sugar-sweetened beverages.

Perceived threat and fear responses to e-cigarette warning label messages: Results from 16 focus groups with U.S. youth and adults

AIMS

A warning on e-cigarette packaging is one way the U.S. government can inform the public of known harms of e-cigarette use. Currently, the only required warning on these products is: "WARNING: This product contains nicotine. Nicotine is an addictive chemical." This exploratory study aims to inform potential future investigations and FDA decisions regarding alternative warnings that may generate fear in addition to being intentionally informational.

METHOD

Data were obtained from responses by 16 online focus groups with adult (N = 47, age range = 18-64) and youth (N = 32, age range 14-16) participants with various smoking and vaping experiences. We showed each focus group a set of hypothetical e-cigarette warning labels to determine how they respond to currently existing public statements that communicate information on the toxicity of ingredients in e-cigarettes, potential health risks, addiction to nicotine, and the uncertainty of the science regarding health effects of using these products. The focus group interviews were audio recorded and transcribed. Transcripts were subjected to a multiphase coding process to identify common response themes. Codes derived from the Extended Parallel Processing Model were then applied to understand impact of potentially fear-inducing language by warning category and age group.

RESULTS

For adults, all warnings-except those about addiction-gave rise to spontaneous danger control (intended) responses, such as quit intentions. Warnings highlighting cognitive and uncertain effects may be particularly promising for adult consumers of tobacco products because both gengerated danger control and response efficacy without evidence of fear control. However, responses also suggest that warnings risk discouraging some adults who use combustible cigarettes from transitioning to e-cigarettes for harm reduction. For youth, while evidence of response efficacy and danger control emerged among youth exposed to messages in all warning categories but one-addiction-unproductive reactions indicative of fear control were also prevalent among youth respondent across most warning types. On average, youth were more skeptical than adults about the harms of using e-cigarettes.

POLICY IMPLICATIONS

Implications of study findings for the development of future effective e-cigarette warning messages are explored.

Messages in prescription drug advertising for four chronic diseases, 2003-2016: A content analysis

The objective of this study was to examine the frequency and content of messages related to pharmacological and evidence-based, non-pharmaceutical treatments in direct-to-consumer advertising (DTCA) for prescription drugs treating four chronic diseases in the United States. We used content coding to identify theory-informed categories of messages appearing in a large sample of heart disease, diabetes, depression, and osteoarthritis advertisements, appearing on national and local television between 2003 and 2016 (N = 11,347,070). The data were originally accessed in 2019 and analyzed in 2020-2021. The central message in all pharmaceutical DTCA was drug efficacy. Advertisements for diabetes and heart disease, but not depression or osteoarthritis, contained general (not central) messages about diet and exercise. Advertisements for heart disease primarily portrayed diet and exercise as insufficient for controlling the target health condition. No advertisements in our sample portrayed changes in diet or physical activity as an alternative to drugs. Pharmaceutical DTCA across health conditions employ similar strategies to promote use of the advertised drug but vary widely in whether and how they describe non-pharmaceutical treatments that complement or serve as alternatives to medications. Regulators should consider the potential spillover effects of non-pharmaceutical messages in pharmaceutical DTCA when considering future regulatory endeavors.

Maintaining a Fair Balance? Narrative and Non-Narrative Strategies in Televised Direct-to-Consumer Advertisements for Prescription Drugs Aired in the United States, 2003-2016

Televised direct-to-consumer advertising for prescription drugs (hereafter DTCA) are among the most widespread forms of health communication encountered by American adults. DTCA shape public understanding of health problems and support the commercial interests of pharmaceutical companies by offering prescription drugs as a treatment option. The U.S. Food and Drug Administration (FDA) requires DTCA to present fair and balanced information regarding drug benefits versus risks. While narrative persuasion theory suggests that narratives can enhance persuasion by facilitating message processing and reducing counter-arguing, prior assessments of the balance between drug benefits versus risk information in DTCA have largely overlooked whether the ads employ narratives and/or other evidentiary strategies that may confer a persuasive advantage. This study content analyzed narrativity in DTCA aired on television between 2003 and 2016 for four different health conditions (heart disease, diabetes, depression, and osteoarthritis). Results showed that while televised DTCA spent more time discussing drug risks than drug benefits, both narratives and factual evidence were more frequently used to communicate drug benefits than drug risks. These findings raise concerns that narratives are strategically used by DTCA to highlight drug benefits rather than drug risks, which could lead to inaccurate perceptions of drug risks among viewers.

Disparities in exposure to television advertising of sugar-sweetened and non-nutritive sweetened beverages among U.S. adults and teens, 2007-2013

The objective of this study was to estimate disparities in exposure to television advertising of sugar-sweetened and non-nutritive sweetened beverages among U.S. adults and teens. Data (2007-2013) came from the National Consumer Survey and included 115,510 adult respondents (age 18+) and 8635 teen respondents (age 12-17). The data was originally accessed in 2018 and analyzed in 2019-2020. The main outcomes were individual-level estimated exposure to advertisements for regular soda, diet soda, and energy/sport drinks. The main exposures were by race/ethnicity, household income, and educational attainment. Non-white adults (teens) were exposed to an estimated (per year) 101.5 (190.1) regular soda ads, 49.5 (61.2) diet soda ads, and 157.1 (279.6) energy/sport ads per year while white respondents were exposed to 97.5 (127.7) regular soda ads, 45.8 (44.2) diet soda ads, and 123.9 (192.0) energy/sport ads per year. Adult (teen) respondents who were non-white with low incomes and with low educational attainment were exposed to 4.7% (53.7%) more regular soda ads, 6.6% (43.8%) more diet ads, and 23.2% (56.2%) more energy/sport ads than respondents who were white with high incomes and high educational attainment. Demographic and socio-economic groups with a higher prevalence of obesity were exposed to significantly more advertisements for sugar-sweetened beverages. When evaluating potential policies to regulate marketing of sugar-sweetened and non-nutritive sweetened beverages, policymakers should consider the disparate exposure of at-risk populations to advertising of sugar-sweetened and non-nutritive sweetened beverages.

Exposure to televised political campaign advertisements aired in the United States 2015-2016 election cycle and psychological distress

CONTEXT

Prior research suggests the potential for political campaign advertisements to increase psychological distress among viewers. The current study tests relationships between estimated exposure to campaign advertising and the odds of respondents reporting that a doctor told them they have anxiety, depression, insomnia, or (as a negative control) cancer.

METHODS

A secondary analysis of U.S. data on televised campaign ad airings from January 2015 to November 2016 (n = 4,659,038 airings) and five waves of a mail survey on television viewing patterns and self-reported medical conditions from November 2015 to March 2017 (n = 28,199 respondents from n = 16,204 unique households in the U.S.).

FINDINGS

A 1 percent increase in the estimated volume of campaign advertising exposure was associated with a 0.06 [95% CI 0.03-0.09] percentage point increase in the odds of a respondent being told by a doctor that they have anxiety in the past 12 months. We observed this association regardless of the political party of the ad sponsor, the political party of the respondent, or their statistical interaction. We also observed this association for both Presidential campaign ads and non-Presidential (including local, state, and U.S. congressional election) campaign ads, providing evidence that these relationships were not driven by the unique divisiveness of the race between Donald Trump and Hilary Clinton. Some topic-specific models offered additional evidence of association between estimated volume of campaign advertising exposure and the odds of being told by a doctor that they have depression or insomnia, but these patterns were less consistent across models that utilized different categories of campaign exposure. Campaign ad exposure was not associated with cancer, which served as a negative control comparison.

CONCLUSIONS

There was a consistent positive association between the volume of campaign advertising exposure and a reported diagnosis of anxiety among American adults.

Estimated televised alcohol advertising exposure in the past year and associations with past 30-day drinking behavior among American adults: results from a secondary analysis of large-scale advertising and survey data

AIMS

To estimate the volume of past-year televised alcohol advertising exposure by product category and demographic group among adults living in the United States and test associations between estimated alcohol advertising exposure and past 30-day drinking behavior.

DESIGN

Secondary analysis of data from two national-level US data sets: Kantar data on appearances of televised alcohol advertisements and data from the Simmons National Consumer Survey (NCS), a large national mail survey on television viewing patterns and consumer behavior.

SETTING

United States.

PARTICIPANTS

A total of 54 671 adults, aged 21 years and older, who were randomly selected to participate in the Simmons NCS.

MEASUREMENTS

Estimated exposure to televised advertisements for beer, wine and spirits, self-reported alcohol use in the past year and number of drinks consumed in the past 30 days.

FINDINGS

The average respondent was exposed to an estimated 576 [95% confidence interval (CI) = 570-582] televised alcohol advertisements in the year preceding their survey. Exposure was higher among males versus females and African Americans versus whites. A 1% increase in the estimated volume of advertisement exposure was associated with a 0.11 (95% CI = 0.08-0.13) percentage point increase in the odds of having at least one drink in the last 30 days and, among past 30-day drinkers, a 0.05 (95% CI = 0.04-0.07) per cent increase in the number of alcoholic drinks consumed. Associations were consistent across product categories and demographics.

CONCLUSIONS

There appears to be a small but consistent positive association between alcohol advertising exposure and drinking behavior among American adults.

Should Graphic Warning Labels Proposed for Cigarette Packages Sold in the United States Mention the Food and Drug Administration?

INTRODUCTION

Under the US Family Smoking Prevention and Tobacco Control Act, the US Food and Drug Administration (FDA) has the authority to implement graphic warning labels (GWLs) on cigarette packages. Neither the original labels proposed by the FDA nor the revised labels include a source to indicate sponsorship of the warnings. This study tests the potential impact of adding a sponsor to the content of GWLs.

METHODS

We recruited adult smokers (N = 245) and middle-school youth (N = 242) from low-income areas in the Northeastern US. We randomly assigned participants to view one of three versions of the original FDA-proposed warning labels in a between-subjects experiment: no sponsor, "US Food and Drug Administration," or "American Cancer Society" sponsor. We tested the effect of varying sponsorship on source attribution and source credibility.

RESULTS

Compared to unsponsored labels, FDA sponsorship increased source attributions that the FDA sponsored the labels among both middle-school, largely nonsmoking youth and adult smokers. However, sponsorship had no effect on source credibility among either population.

CONCLUSIONS

We found no evidence that adding FDA as the source is likely to boost source credibility judgments, at least in the short term; though doing so would not appear to have adverse effects on credibility judgments. As such, our data are largely consistent with the Tobacco Control Act's provisions that allow, but do not require, FDA sponsorship on the labels.

IMPLICATIONS

This study addresses the FDA's regulatory efforts by informing the possible design and content of future cigarette warning labels. Our results do not offer compelling evidence that adding the FDA name on GWLs will directly increase source credibility. Future work may test more explicit FDA source labeling and continue to examine the credibility of tobacco message content among high-priority populations.

Effects of 30% and 50% Cigarette Pack Graphic Warning Labels on Visual Attention, Negative Affect, Quit Intentions, and Smoking Susceptibility among Disadvantaged Populations in the United States

Introduction

Though the WHO Framework Convention for Tobacco Control (FCTC) calls for the implementation of large graphic warning labels (GWLs) on cigarette boxes, the courts have blocked the implementation of 50% labels in the United States. We conducted an experiment to explore whether changing the size of GWLs is associated with changes in visual attention, negative affect, risk beliefs, and behavioral intentions.

Method

We recruited adult smokers (N = 238) and middle-school youth (N = 237) throughout the state of New York in May 2016. We randomly assigned participants to one of three between-subject conditions (no GWL [control], 30% GWL, 50% GWL).

Results

Adult and youth participants looked at the GWLs longer when the GWL covered 50% versus 30% of the pack's front. Increasing GWL size from 30% to 50% did not influence negative affect or risk beliefs, though both GWL sizes increased negative affect relative to the no-GWL control group. Exposure to 50% GWLs increased adult smokers' intentions to quit compared to no-GWL, but smokers exposed to 30% GWLs did not differ from control. There were no differences between 50% GWLs, 30% GWLs, and control on youth smoking susceptibility.

Conclusions

Findings provide some evidence of the benefits of a 50% versus 30% GWL covering the front of the pack for adult smokers and at-risk youth from socioeconomically disadvantaged backgrounds-though not on all outcomes.

Implications

This research shows that 30% GWLs on cigarette packages increase negative affect relative to packages without front-of-package GWLs. Larger GWLs on cigarette packages (50% vs. 30%) increase visual attention to the warning and its pictorial content among low-SES smokers and at-risk youth but do not further increase negative affect. A 50% GWL increased adults' quit intention compared to no GWL at all, but we were underpowered to detect modest differences in quit intentions between a 50% and 30% GWL. Future work should thus continue to explore the boundary conditions under which relatively larger GWLs influence cognitive, affective, and behavioral outcomes.

Testing the Effects of Certain versus Hypothetical Language in Health Risk Messages

This paper tests how the certainty or hypotheticality conveyed through language can be harnessed to enhance the effectiveness of targeted messaging about health risks. We conducted two experiments with adult smokers (n = 317) and middle school youth (n = 321) from low-income communities in the context of pictorial cigarette warning labels. We manipulated hypotheticality of risk through verb modality: 1. non-modal (present tense, e.g., smoking causes cancer), and modal/hypothetical (2. may, 3. can, and 4. will). For adult smokers, definitive (present tense) wording led to greater health risk beliefs, compared to hypothetical wording, among adult males but not females. For youth, contrary to what might seem intuitive, the more hypothetical may verb modality was more effective than the present tense language in promoting health risk beliefs. Among youth, greater health risk beliefs were also associated with reduced susceptibility to use cigarettes. No differences in negative affect by hypotheticality of language were found for either population. We discuss these findings in relation to the theoretical implications for the concept of hypotheticality and the application of construal level theory to strategic health communication.

Independent or synergistic? Effects of varying size and using pictorial images in tobacco health warning labels

INTRODUCTION

Legal challenges have blocked the implementation of large, pictorial health warning labels (HWLs) in the U.S. In light of future legal questions the U.S. Food and Drug Administration may face in proposing alternative HWLs, we examined whether less restrictive HWL versions on the front of packs-smaller HWLs and/or text-only HWLs that do not include pictorial imagery-may be sufficient to promote cognitive and affective outcomes associated with smoking cessation.

METHODS

We recruited low-income smokers in two separate experiments through field-based recruitment methods (Study 1, N = 497) or Amazon Mechanical Turk (MTurk) (Study 2, N = 495). In both studies, we randomly assigned participants to a no-HWL control condition or one of four HWL conditions in a 2 (pictorial vs. text-only) × 2 (50% vs. 30% size) between-subjects design.

RESULTS

Relative to text-only HWLs, pictorial HWLs increased negative affect but not risk belief acceptance, cognitive elaboration about smoking harms, or quit intentions. The 50% HWLs increased quit intentions relative to the control condition in both studies. The 50% HWLs also outperformed the 30% HWLs in promoting quit intentions in Study 2. Subsequent analyses revealed that this effect in Study 2 may have been driven by the 50% HWLs strengthening the relationship between risk-related thoughts and intentions, although there was no evidence for this pattern in Study 1. We found no evidence for interaction effects between the pictorial and size manipulations.

CONCLUSIONS

Our findings suggest that 50% HWLs, whether pictorial or text-only, can encourage low-income smokers to consider quitting under some conditions.

Effects of Varying Color, Imagery, and Text of Cigarette Package Warning Labels among Socioeconomically Disadvantaged Middle School Youth and Adult Smokers

The U.S. Family Smoking Prevention and Tobacco Control Act (Tobacco Control Act) of 2009 paved the way for the Food and Drug Administration (FDA) to propose nine different graphic warning labels (GWLs) intended for prominent placement on the front and back of cigarette packs and on cigarette advertisements. Those GWLs were adjudicated as unconstitutional on the ground that they unnecessarily infringed tobacco companies' free speech without sufficiently advancing the government's public health interests. This study examines whether less extensive alternatives to the original full-color GWLs, including black-and-white GWLs and text-only options, have similar or divergent effects on visual attention, negative affect, and health risk beliefs. We used a mobile media research lab to conduct a randomized experiment with two populations residing in socioeconomically disadvantaged communities: biochemically confirmed adult smokers (N = 313) and middle school youth (N = 340). Results indicate that full-color GWLs capture attention for longer than black-and-white GWLs among both youth and adult smokers. Among adults, packages with GWLs (in either color or black-and-white) engendered more negative affect than those with text-only labels, while text-only produced greater negative affect than the packages with brand imagery only. Among youth, GWLs and text-only labels produced comparable levels of negative affect, albeit more so than brand imagery. We thus offer mixed findings related to the claim that a less extensive alternative could satisfy the government's compelling public health interest to reduce cigarette smoking rates.

Using graphic warning labels to counter effects of social cues and brand imagery in cigarette advertising

Exposure to cigarette advertising can increase the likelihood of youth smoking initiation and may encourage people who already smoke to continue. Requiring prominent, graphic warning labels could reduce these effects. We test whether graphic versus text-only warning labels in cigarette advertisements influence cognitive and emotional factors associated with youth susceptibility to smoking and adult intentions to quit. We conducted two randomized, between-subjects experiments with middle-school youth (n = 474) and adult smokers (n = 451). Both studies employed a two (graphic or text-only warnings) by two (advertisements with social cues or brand imagery) factorial design with a fifth, offset control group (social cue advertisements with the current US Surgeon General's Warning). Graphic warnings outperformed text-only warnings in reducing visual attention to the advertisement, generating visual attention to the warning and arousing more negative affect. Graphic warnings also reduced the appeal of cigarette brands among youth relative to social cue advertisements with the Surgeon General's warnings. None of the warnings (graphic or textual) influenced health risk beliefs. Graphic warning labels on cigarette advertisements appear to have effects similar to those observed on cigarette packs in previous work, with an added benefit of reducing cigarette brand appeal among youth.

Testing competing explanations for graphic warning label effects among adult smokers and non-smoking youth

RATIONALE

The United States courts have blocked the implementation of graphic warning labels on cigarette packages (GWLs). This decision was based, in part, on the premise that GWLs are unnecessarily emotional and are meant to scare rather than inform consumers about smoking's health effects. However, research in judgment and decision-making suggests these relationships are more complex.

OBJECTIVE

In this article, we draw on several theoretical frameworks that lead to competing hypotheses about the relationships between negative affect, health risk beliefs, and quit intentions (among adult smokers) or susceptibility to start smoking (among non-smoking youth).

METHOD

We tested these competing mediation models using data from two experiments with two populations each-adult smokers (Ns = 313 and 238) and primarily non-smoking middle-school youth (Ns = 340 and 237). Using mobile recruitment methods, we focused specifically on individuals from socioeconomically disadvantaged communities in rural and urban areas of the Northeastern United States.

RESULTS

The best fitting model across all four datasets was one in which label-induced negative affect (a) directly predicted intentions/susceptibility but also (b) indirectly predicted intentions/susceptibility via risk beliefs. Although mediation analyses did not demonstrate significant serial mediation effects of label exposure on intentions/susceptibility through negative affect then risk beliefs, there was some evidence that label exposure indirectly promoted adults' quit intentions through negative affect. Additionally, negative affect consistently mediated the indirect effect of label exposure on strengthened risk beliefs among adults and youth.

CONCLUSIONS

These results speak to the importance of negative affect in directly motivating adult smokers' quit intentions but also serving an informational function, directing adult smokers and non-smoking youth to accept the health risks of smoking.

Vitamin panacea: Is advertising fueling demand for products with uncertain scientific benefit?

This study examines the effect of advertising on demand for vitamins-products with spiraling sales despite little evidence of efficacy. We merge seven years (2003-2009) of advertising data from Kantar Media with the Simmons National Consumer Survey to estimate individual-level vitamin print and television ad exposure effects. Identification relies on exploiting exogenous variation in year-to-year advertising exposure by controlling for each individual's unique media consumption. We find that increasing advertising exposure from zero to the mean number of ads increases the probability of consumption by 1.2 and 0.8% points (or 2 and 1.4%) in print and television respectively. Stratifications by the presence of health conditions suggests that in print demand is being driven by both healthy and sick individuals.

Mixed Messages, Mixed Outcomes: Exposure to Direct-to-Consumer Advertising for Statin Drugs is Associated with More Frequent Visits to Fast Food Restaurants and Exercise

This study examines whether exposure to direct-to-consumer advertising (DTCAs) for statin drugs is associated with non-pharmaceutical behaviors to prevent cardiovascular disease. We focus on the relationship between statin drug DTCA exposure and the frequency of (a) visits to fast-food restaurants and (b) exercise. We combine data on the televised broadcast availability of statin drug DTCAs in large media markets in the United States with 18 waves of the Simmons National Consumer Survey (NCS; n = 120, 229) from 2001 to 2009. We find that statin drug DTCA exposure is associated, in a dose-response pattern, with modest increases in the frequency of exercise and large increases in the frequency of fast-food-restaurant visits. The relationship between statin DTCA exposure and fast-food-restaurant visits were largely consistent in direction but differed in magnitude between those without a previous diagnosis of high cholesterol and those treating high cholesterol with a statin. We conclude with a discussion of the implications of these results for future research on pharmaceutical DTCA and population health.

Theoretical Foundations of Appeals Used in Alcohol-Abuse and Drunk-Driving Public Service Announcements in the United States, 1995-2010

PURPOSE

The study identifies the extent to which theoretical constructs drawn from well-established message effect communication theories are reflected in the content of alcohol-related public service announcements (PSAs) airing in the United States over a 16-year period.

DESIGN

Content analysis of 18 530 141 alcohol-abuse (AA) and drunk-driving (DD) PSAs appearing on national network and local cable television stations in the 210 largest designated marketing areas (DMAs) from January 1995 through December 2010.

MEASURES

The authors developed a detailed content analytic codebook and trained undergraduate coders to reliably identify the extent to which theoretical constructs and other creative ad elements are reflected in the PSAs. We show these patterns using basic descriptive statistics.

RESULTS

Although both classes of alcohol-related PSAs used strategies that are consistent with major message effect theories, their specific theoretical orientations differed dramatically. The AA PSAs were generally consistent with constructs emphasized by the Extended Parallel Process Model (EPPM), whereas DD PSAs were more likely to use normative strategies emphasized by the Focus Theory of Narrative Conduct (FTNC) or source credibility appeals central to the Elaboration Likelihood Model.

CONCLUSION

Having identified message content, future research should use deductive approaches to determine if volume and message content of alcohol-control PSAs have an impact on measures of alcohol consumption and/or measures of drunk driving, such as fatalities or driving while intoxicated/driving under the influence arrests.

An examination of structure-function claims in dietary supplement advertising in the U.S.: 2003-2009

Dietary supplement advertising cannot claim a causal link between the product and the treatment, prevention, or cure of a disease unless manufacturers seek approval from the FDA for a health claim. Manufacturers can make structure-function (S-F) claims without FDA approval linking a supplement to a body function or system using words such as "may help" or "promotes." These S-F claims are examined in this study in order to determine whether they mimic health claims for which the FDA requires stricter scientific evidence. Data include S-F claims in supplement advertisements (N=6179) appearing in US nationally circulated magazines (N=137) from 2003 to 2009. All advertisements were comprehensively coded for S-F claims, seals of approval, and other claims of guarantee. S-F claims associate supplements with a wide variety of health conditions, many of which are serious diseases and/or ailments. A significant number of the specific verbs used in these S-F claims are indicative of disease treatment/cure effects, thereby possibly mimicking health claims to the average consumer. The strength of the clinical associations made are largely unsubstantiated in the medical literature. Claims that a product is "scientifically proven" or "guaranteed" were largely unsubstantiated by clinical literature. Ads carrying externally validating seals of approval were highly prevalent. S-F claims that strongly mimic FDA-prohibited health claims are likely to create confusion in interpretation and possible public health concerns are discussed.

Market-level exposure to state antismoking media campaigns and public support for tobacco control policy in the United States, 2001-2002

OBJECTIVE

This study tests whether exposure to state antismoking media campaigns is associated with increased support for comprehensive bans on smoking indoors and cigarette advertising.

METHODS

We combine commercially available data on market-level state-sponsored antismoking advertisements with three waves of the Current Population Survey's Tobacco Use Supplement to test the relationship between market-level volume of state antismoking advertising exposure and support for tobacco control policy between 2001 and 2002. We use logistic regression to assess which message themes employed in the advertisements are associated with increased support for tobacco control policy.

RESULTS

The overall market-level volume of exposure to state antismoking ads targeted to adults or the general population was associated with significant increases in support for comprehensive indoor smoking bans. These effects were driven by exposure to ads emphasising the health consequences of smoking to others, anti-industry appeals and irrationality/addiction appeals. Evidence of campaign impact on support for tobacco advertising bans was less clear and, when statistically significant, small in magnitude relative to the impact of the state economic and tobacco control policy environment.

CONCLUSIONS

This study shows that that large-scale antismoking media campaigns can have a meaningful secondary impact on support for comprehensive indoor smoking bans. Future research should identify the conditions under which mass media campaigns primarily targeting smoking behaviour may influence public support for a variety of other tobacco control policies.

Effects of exposure to direct-to-consumer television advertising for statin drugs on food and exercise guilt

OBJECTIVE

Pharmaceutical direct-to-consumer advertising (DTCA) is widely prevalent on US television. This study tests the relationship between estimated exposure to DTCA for statin drugs, which often feature mixed messages about the efficacy of diet and exercise in reducing risk of cholesterol and heart disease, and guilty feelings regarding food and exercise.

METHODS

A series of repeated cross-sectional surveys of the US population between 2001 and 2007 (N=106,859 adults aged 18 and older) were combined with data on the frequency of DTCA appearances on national, cable, and local television during the same time period.

RESULTS

Adjusting for potential confounders with ordinary least squares (OLS) regression, increased potential exposure to statin DTCA was associated with increased food guilt (in a dose-response pattern) and exercise guilt (in a threshold pattern).

CONCLUSION

This study provides new evidence that DTCA has potential to influence emotional well-being as well as direct behavioral responses emphasized in previous academic research.

PRACTICE IMPLICATIONS

Health practitioners should be prepared to encounter and counsel patients who are prompted by DTCA to feel guilty about their food and exercise behaviors, feelings which may impact the likelihood of adherence to prescribed behavioral modification for weight management.

Direct-to-consumer television advertising exposure, diagnosis with high cholesterol, and statin use

BACKGROUND

While statin drugs are recommended for secondary prevention of coronary heart disease (CHD), there is no medical consensus on whether or not a statin should be added to lifestyle change efforts for primary prevention of CHD. Previous research suggests that exposure to direct-to-consumer advertising (DTCA) increases drug demand among those at comparatively low risk. Research has yet to examine whether individual-level DTCA exposure may influence statin use among men and women at high, moderate, or low risk for future cardiac events.

OBJECTIVE

To determine the relationship between estimated exposure to DTCA for statin drugs and two clinical variables: diagnosis with high cholesterol and statin use.

DESIGN

We used logistic regression to analyze repeated cross-sectional surveys of the United States population, merged with data on the frequency of DTCA appearances on national, cable, and local television, between 2001 and 2007.

PARTICIPANTS

American adults (n=106,685) aged 18 and older.

MAIN MEASURES

Levels of exposure to statin DTCA, based on ad appearances and TV viewing patterns; self-reports of whether or not a respondent has been diagnosed with high cholesterol, and whether or not a respondent took a statin in the past year.

KEY RESULTS

Adjusting for potential confounders, we estimate that exposure to statin ads increased the odds of being diagnosed with high cholesterol by 16 to 20 %, and increased statin use by 16 to 22 %, among both men and women (p<0.05). These associations were driven almost exclusively by men and women at low risk for future cardiac events. There was also evidence of a negative association between DTCA exposure and statin use among high-risk women (p<0.05) CONCLUSIONS: This study provides new evidence that DTCA may promote over-diagnosis of high cholesterol and over-treatment for populations where risks of statin use may outweigh potential benefits.

"When diet and exercise are not enough": an examination of lifestyle change inefficacy claims in direct-to-consumer advertising

Previous research suggests that direct-to-consumer (DTC) advertisements for pharmaceutical drugs have the potential to influence consumers' perceptions of whether symptoms should be treated medically and/or through behavior change. However, the relative frequency of messages emphasizing these approaches in pharmaceutical advertising remains largely unknown. A content analysis of print and television advertisements for cholesterol management medication between 1994 and 2005 (for print) and between 1999 and 2007 (for television) was conducted. First, the extent to which established theoretical constructs drawn from health communication scholarship are depicted in the content of DTC cholesterol advertisements is quantified. Second, specific claims about behavior change inefficacy when a pharmaceutical alternative is available are identified. Findings indicate that DTC ads offer many mixed messages about the efficacy of diet and exercise in reducing cholesterol and risk of heart disease. Theoretical and practical implications of this work are discussed.

The unintended consequences of disclosure: effect of manipulating sponsor identification on the perceived credibility and effectiveness of smoking cessation advertisements

One reason that tobacco-sponsored smoking cessation ads are less effective than those sponsored by public health agencies may be that the persuasive arguments in tobacco-sponsored ads are inherently weaker than arguments made in public health ads. An alternate explanation is that sponsorship disclosure on the face of the ad activates resistance, partly because of credibility judgments directed toward tobacco companies. The authors test hypotheses in a 3 (sponsor identification) × 2 (ad content) randomized factorial experiment (N = 270). Results indicate that judgments of sponsor credibility play a mediating role in perceptions of ad effectiveness, with identification of a tobacco company as the sponsor of cessation ads undermining perceived credibility compared with the same ads without the tobacco company identified. However, the reduction in credibility resulting from tobacco sponsorship can be partially overcome when the sponsor is placed on more direct ad content (public health ads). The effects of credibility on perceived effectiveness were stronger for more ambiguous ad content and driven by participants with lower levels of involvement (nonsmokers). Credibility judgments are not as important when the ad content is more direct about the health consequences of smoking. Implications of study results for theory and public policy are explored.

The impact of direct-to-consumer television and magazine advertising on antidepressant use

We examine whether exposure to direct-to-consumer advertising (DTCA) for antidepressant drugs affects individual use of these medications among those suffering from depression. Prior studies have almost exclusively relied on making connections between national or market-level advertising volume/expenditures and national or individual-level usage of medications. This is the first study to: estimate the impact of individual-level exposure to DTCA on individual-level use of antidepressants; estimate the impact of individual-level exposure to television DTCA on individual-level use in any drug class; consider the relative and interactive impact of DTCA in two different media in any drug class; and, consider the heterogeneity of impact among different populations in an econometric framework in the antidepressant market. There are also important limitations to note. Unlike prior market level studies that use monthly data, we are limited to aggregated annual data. Our measures of potential advertising exposure are constructed assuming that media consumption patterns are stable during the year. We are also not able to study the impact of advertising on use of antidepressants for conditions other than depression, such as anxiety disorders. We find that: DTCA impacts antidepressant use in a statistically and economically significant manner; that these effects are present in both television and magazine advertising exposure but do not appear to have interactive effects; are stronger for women than for men in the magazine medium, but are about equally strong for men and women in the TV medium; and, are somewhat stronger for groups suffering from more severe forms of depression. The overall size of the effect is a 6-10 percentage point increase in antidepressant use from being exposed to television advertising; the corresponding magazine effects are between 3 and 4 percentage points.

Fair balance in direct-to-consumer antidepressant print and television advertising, 1995-2007

The authors evaluated fair balance in the presentation of risks and benefits in a large sample of direct-to-consumer advertising for prescription antidepressant medications appearing in magazines (1995-2006) and television (1999-2007) to assess how well they meet U.S. Food and Drug Administration guidelines. Using content analysis to capture relevant dimensions of the ads, results indicated that (a) considerably less attention is given to risks relative to benefits and (b) implicit ad content favors communication of drug benefits over risks, but that fair balance in direct-to-consumer ads has improved over time. The authors discuss policy implications and explore future research directions.

The potential contribution of mentor programs to relational permanency for youth aging out of foster care

This article summarizes published research regarding the effectiveness of mentor programs in general, and for youth in foster care specifically, as a basis for evidence-based practice in child welfare. It examines the pros and cons of mentor programs and characteristics of programs that are more or less effective for achieving specific social goals. The author explores the opportunity cost of investments in transitional mentor programs versus efforts to find permanent parents for youth aging out of care, and concludes with practice and policy implications of these findings.

Two unique RNA species of the nodavirus black beetle virus

Two-dimensional fingerprinting of RNase T(1)-derived oligonucleotides of the two individual RNA segments of the Nodavirus black beetle virus indicates that each RNA species possesses a distinct nucleotide sequence. Species 1 RNA has a genome complexity of approximately 3,000 nucleotides, and species 2 RNA is composed of approximately 1,500 nucleotides. Submolar amounts of oligonucleotides apparently derived from a third virus-specific RNA were also detected in black beetle virus RNA preparations.

Care or scare: the safety of youth in congregate care in New York City

OBJECTIVE

This qualitative study examined stakeholders' perceptions of the safety of youth ages 12 and older living in congregate care facilities within the New York City foster care system. The study explored the youth's physical safety, the safety of their personal belongings, the physical conditions of congregate care settings, and the relationship between staff quality and youth safety.

METHOD

The study involved interviews with family court judges, representatives of private child welfare agencies, attorneys who represent children in foster care, social workers, representatives of advocacy and other relevant organizations in New York City, and former foster youth who had been placed in congregate care settings.

RESULTS

Safety in congregate care environments was an issue of significant concern. Threats to the youth's safety were found to emanate from peer-on-peer violence, stealing of personal belongings, inappropriate staff conduct, and the poor physical conditions of facilities. Youth's sense of safety was strongly linked to staff quality, including staff ability to relate effectively to youth and to maintain control of congregate care environments.

CONCLUSIONS

Existing regulations in New York State appear to have had little effect in ensuring the safety of youth in many group and residential care facilities. Steps to improve safety outcomes for youth in these settings are proposed.

Characterization of the transcription map and Rev activity of a highly cytopathic feline immunodeficiency virus

A highly cytopathic feline immunodeficiency virus, FIV-Oma, was previously isolated from a nondomestic cat. In this report, we describe experiments to characterize its transcription map and examine its Rev activity. The temporal progression of viral gene expression is similar to that of HIV-1. The splicing pattern of viral transcripts was determined by sequence analysis of RT-PCR-amplified viral cDNAs. In vitro transcription and translation of two putative rev cDNAs revealed that they encode at least one 22-kDa protein. The Rev-responsive element (RRE) of FIV-Oma, identified by computer-assisted RNA secondary structure analysis, was inserted into the intron of an HIV-1-derived reporter plasmid and used in a transient transfection assay for Rev activity. Cotransfection of the RRE construct with the two rev cDNA clones significantly increased the expression of the reporter gene linked to the RRE, indicating that both transcripts encode an active Rev protein. The Rev activity of FIV-Oma is 5 to 8 times higher than that of a domestic cat FIV isolate, FIV-PPR. Our experiments also demonstrate the heterologous interaction of FIV-PPR Rev with the FIV-Oma RRE, even though the RREs of the two viruses have very little nucleotide sequence identity.

Proviral organization and sequence analysis of feline immunodeficiency virus isolated from a Pallas' cat

The nucleotide sequence and genomic organization have been determined for a highly cytopathic feline immunodeficiency virus (FIV) isolated from a Pallas' cat. The 9747-bp provirus of this virus, FIV-Oma, has typical lentivirus organization with LTRs, gag, pol, and env open reading frames (ORFs), putative vif and rev ORFs, and an ORF similar to ORF2/ORFA of domestic cat FIV isolates. Although the FIV-Oma provirus is 300 to 600 bp longer than other FIV proviruses, these additional bases are distributed throughout the genome. Phylogenetic analysis of a conserved region of the pol gene suggests that FIV-Oma is more closely related to some of the puma and lion lentiviruses than it is to domestic cat FIV isolates; however, many regions of the genome exhibit extensive nucleotide sequence divergence. None of the eight molecular proviral clones isolated from a genomic library are infectious, but we have constructed an infectious, cytopathic clone of FIV-Oma from subcloned and PCR-amplified fragments of these proviral clones. This clone will be useful for identifying the genetic determinants of FIV-Oma's biological activities.

Sequence analysis and transcriptional activity of the LTR of OLV-CU1, a North American ovine lentivirus

Although ovine lentiviruses have been described in the United States since the early part of this century, North American strains of sheep lentiviruses remain relatively uncharacterized at the molecular level. The LTR of a North American ovine lentivirus, OLV-CU1, was found to be closely related at the molecular and functional levels to visna virus, the Icelandic ovine lentivirus. Sequence analysis of the LTR revealed high identity to other ovine and caprine lentiviruses in key regulatory elements of the upstream promoter region (-25 to -115). However, the R region of the LTR was much less homologous. Transcriptional control of OLV-CU1 in transient transcriptional assays required a conserved putative AP-4 region and possibly an AP-1 like element in the upstream promoter region for moderate to high levels of transcription, much like visna virus. In contrast to visna virus, the downstream region beyond the transcriptional start site was required for virus-specific transactivation.

Isolation of a highly cytopathic lentivirus from a nondomestic cat

A feline immunodeficiency virus-like virus (FIV-Oma) isolated from a Pallas' cat (Otocolobus manul) is highly cytopathic in CrFK cells, in contrast to the chronic, noncytolytic infection established by an FIV isolate from a domestic cat (FIV-Fca). The virions have typical lentivirus morphology, density, and magnesium-dependent reverse transcriptase activity. The major core protein is antigenically cross-reactive with that of FIV-Fca; however, FIV-Oma transcripts do not cross-hybridize with FIV-Fca. A conserved region of the FIV-Oma pol gene has 76 to 80% nucleic acid identify with the corresponding pol regions of other feline lentiviruses and 64 to 69% identity with those of human, ovine, and equine lentiviruses.

Characterization of a New York ovine lentivirus isolate

A lentivirus has been isolated from a Finnish ewe with ovine progressive pneumonia in a closed upstate New York flock. We demonstrated that the virus, designated ovine lentivirus strain CU1 (OLV-CU1), is biologically, biochemically and molecularly related to, but distinct from, previously described sheep and goat lentiviruses. Nine of 32 ewes (from the affected flock) with precipitating antibodies for ovine lentivirus also produced antibodies that were able to neutralize the infectivity of OLV-CU1. The virus replicated in cultured sheep fibroblasts and caused the formation of large multi-nucleated cells. OLV-CU1-specific RNA transcripts found in infected cells and virion antigenic proteins were similar to those of other small ruminant lentiviruses. However, the virus was distinguished from other isolates at the DNA level by nucleic acid hybridization, restriction endonuclease mapping and partial sequencing of the virus genome.

Suppression of lymphocyte blastogenesis to mitogens in cats experimentally infected with feline immunodeficiency virus

Lymphocytes from normal cats or cats experimentally infected with feline immunodeficiency virus (FIV) were stimulated with phytohemagglutinin, pokeweed mitogen, or concanavalin A. Lymphocytes from infected cats had lower responses than those from uninfected cats. These results support the hypothesis that FIV induces immunosuppression.

The genomic DNA organisation and evolution of a retrovirus-transmissible family of mouse (VL30) genetic elements

The sequence organisation of endogenous VL30 elements in the mouse genome was investigated by using a cloned representative of a retrovirus-transmissible VL30 cDNA. The majority of dispersed VL30 sequences could be assigned to a proviral-like structure 5.2-5.3 kbp long and bounded by long terminal repeats (LTRs). The existence of a hierarchy of evolutionarily conserved elements was rather limited and sequence heterogeneity between different elements was randomly distributed. However, the retrovirus-transmissible class of VL30 element was found to represent a distinct minority subgroup distinguishable by restriction sites and size (4.6-4.9 kbp long). Analysis of sequence conservation showed that VL30 elements display a more rapid turnover than endogenous murine leukaemia virus-related proviral sequences, and that VL30 LTRs show the most limited evolutionary distribution. Although discrete subsets of VL30 unique sequence were conserved in different rodents, the location of conserved regions was found to be variable, arguing against the presence of a functionally conserved protein coding region. These observations support the hypothesis that high frequency recombination, probably occurring during reverse transcription and the accompanying processes of duplicative transposition and amplification, have been a major determinant in the mode of evolution of the VL30 gene family.

The homologue of the Duchenne locus is defective in X-linked muscular dystrophy of dogs

Duchenne muscular dystrophy (DMD) is the most common and the most severe of the muscular dystrophies in man. It is inherited as an X-linked recessive trait and is characterized by ongoing necrosis of skeletal muscle fibres with regeneration and eventually fibrosis and fatty infiltration. Although the gene and gene product which are defective in DMD have recently been identified, the pathogenesis of the disease is still poorly understood. A myopathy has been described in the dog which has been shown to be inherited as an X-linked trait and which is therefore a potential model of the human disease. We have studied the phenotypic expression of the disease, canine X-linked muscular dystrophy (CXMD), and have examined the molecular relationship between it and DMD. We report here that dogs with CXMD faithfully mimic the phenotype of Duchenne muscular dystrophy and that they lack the Duchenne gene transcript and its protein product, dystrophin.

Expression and transmission of a rodent retrovirus-like (VL30) gene family

A transcriptionally active sub-set of the dispersed mouse VL30 family of proviral genetic elements was shown to be highly transmissible as a murine leukaemia virus pseudotype. Newly acquired VL30 proviruses (present at 1 to 2 copies per cell) were shown to be transcriptionally active. These data substantiate the hypothesis that this process of duplicative transposition may have played a major role in the evolution of the gene family and also demonstrate that VL30 elements would be capable of mediating oncogene activation by a promoter-insertion-type mechanism during leukaemia virus-induced tumourgenesis.

Loss of epidermal growth factor receptors and release of transforming growth factors do not correlate with sarcoma virus-transformation in clonally-related NIH/3T3-derived cell lines

Transformation of NIH/3T3 cells by Kirsten murine sarcoma virus (MSV) caused a dramatic reduction in the number of cell-surface receptors for epidermal growth factor (EGF). However, the number of EGF receptors remained at a very low level in a non-tumourigenic revertant cell line isolated from the virus-transformed cells, indicating that an increase in EGF receptors is not a requirement for the phenotypic reversion of Kirsten MSV-transformed 3T3 cells. Serum-free conditioned medium from normal and virus-transformed cell lines contained similar amounts of cell growth-promoting activity as assayed by the ability to stimulate DNA synthesis in quiescent Swiss 3T3 cell cultures. However, the concentrated conditioned medium from these cell lines showed no evidence of beta-transforming growth factor (TGF) activity as assayed by promotion of anchorage-independent growth of untransformed normal rat kidney (NRK) fibroblasts in agarose. The cellular release of alpha-TGF activity was assayed by measuring the ability of concentrated conditioned medium to inhibit the binding of 125I-EGF to Swiss 3T3 cells. Conditioned medium protein from the virus-transformed cell line inhibited 125I-EGF binding but only to the same extent as conditioned medium protein prepared from the untransformed cell line. The alpha-TGF secretion by these cell lines was estimated to be 30-45-fold lower than the level of alpha-TGF released by a well-characterized alpha-TGF-producing cell line (3B11). These results suggest that the induction of TGF release is not a necessary event in the transformation of NIH/3T3 cells by Kirsten MSV.

Genesis of Kirsten murine sarcoma virus: sequence analysis reveals recombination points and potential leukaemogenic determinant on parental leukaemia virus genome

The genome of Kirsten murine sarcoma virus was formed by recombination between Kirsten murine leukaemia virus sequences, and rat sequences derived from a retrovirus-like '30S' (VL30) genetic element encompassing the Kras oncogene. Using cloned DNAs we have determined the nucleotide sequences of the long terminal repeats and adjacent regions, extending across the points of recombination on the sarcoma and leukaemia virus genomes. Our results suggest that discrete regions of homology and other cryptic sequence features, may have constituted recombinational hot-spots involved in the genesis of the Kirsten murine sarcoma virus genome. We have also compared the sequence of the Kirsten murine leukaemia virus p15 env and adjacent long terminal repeat with the corresponding regions of the AKV and Gross A murine leukaemia virus genomes. This comparison has identified a leukaemogenic determinant in the U3 domain of the long terminal repeat, possibly within a enhancer-like sequence element.

Virus-like 30S RNA is selectively packaged by Kirsten leukemia virus in virions of smaller size class. Brief report

Virus particles containing Kirsten murine leukemia virus 38 S RNA and a pseudotyped virus-like cellular 30 S RNA, were partially separable. This provides a means for enriching a population of virions for those containing 30 S RNA.

Expression of Kirsten murine sarcoma virus in transformed nonproducer and revertant NIH/3T3 cells: evidence for cell-mediated resistance to a viral oncogene in phenotypic reversion

Expression of the provirus in a clonally related series of Kirsten murine sarcoma virus-transformed NIH/3T3 nonproducer cell lines was examined at both the transcriptional and translational levels. All cells expressed high levels of genome-sized viral RNA with little variation between cell lines despite differences in provirus integration site and copy number. Expression of K-ras RNA was estimated to be at least 10- to 20-fold higher than that of the mouse cellular homolog of the viral transforming gene. Levels of the virus-coded transforming protein, p21, were similarly elevated, with little variation between nonproducer cells. In two revertant cell lines containing a normal provirus and a rescuable transforming gene, no impairment in expression at either the transcriptional or translational level was found. After superinfection with Kirsten murine sarcoma virus, one revertant became more tumorigenic, whereas the other remained nontumorigenic. These results show that cell transformation by Kirsten murine sarcoma virus is invariably associated with elevated expression of the virus-coded oncogene and that one of the revertants is resistant to the action of the viral transforming gene.

Unusual long terminal repeat sequence of a retrovirus transmissible mouse (VL 30) genetic element: identification of functional domains

We have determined the nucleotide sequence and mapped the transcriptional boundaries in the long terminal repeats (LTRs) and adjacent regions of a retrovirus transmissible virus-like 30S ( VL30 ) mouse genetic element. The 572 base pair LTRs contain transcriptional regulatory sequences and are bounded by short imperfect repeats, with a minus strand tRNAgly primer binding site and a purine rich plus strand primer site flanking each of their inner boundaries. The 3' end of each LTR consists of an extensive 80 base pair redundancy of tRNA primer site and inverted repeat sequences while 41 and 47 base pair imperfect tandem repeats are present between the 5' capping site and the putative polyadenylation signal. Comparison with other retrovirus-like LTR sequences suggests possible modes of recombination that could occur between VL30 and other genetic elements.

Characterization and cloning of the Kirsten murine leukemia virus genome

We have characterized the intracellular and circular unintegrated proviral DNA species of Kirsten murine leukemia virus by restriction mapping using the Southern blotting technique. These studies show the 8.5 kilobase pair genome to possess long terminal repeats (0.5 kilobase pairs in length) which are indistinguishable from those of the derivative Kirsten murine sarcoma virus. In addition, we have identified a 3'-located region in Kirsten murine leukemia virus which is very similar to the putative leukemogenic region of Gross murine leukemia virus. We also report the cloning of the leukemia virus genome using DNA obtained from the endogenous reverse transcriptase reaction of detergent disrupted virions.

Integration of proviral DNA in Kirsten murine sarcoma virus-infected mouse fibroblasts

The structure and sites of integration of proviral DNA were studied in 19 clonally related Kirsten murine sarcoma virus-transformed non-producer NIH/3T3 cell lines. The majority of these cell lines contained a single provirus, inserted colinearly with respect to unintegrated linear viral DNA, and lacking detectable methylation at MspI/HpaII sites. Although all proviruses were located at distinct integration sites in the host cell genome, the possible existence of similarities between some adjacent host flanking sequences, suggested from restriction mapping data, could not be ruled out. In three phenotypically reverted cell lines no change in either proviral DNA or adjacent host flanking sequences was detectable. In addition, the revertant proviruses lacked detectable methylation at MspI/HpaII sites. These findings suggest that changes in cellular function(s) may be responsible for loss of transformed phenotype in these cells.

A novel approach to cloning transcriptionally active retrovirus-like genetic elements from mouse cells

A family of dispersed, moderately repeated mouse genetic elements is expressed as retrovirus-like 30S RNA species (VL30 RNA) which can be transmitted to other cells when packaged as a pseudovirion complex by murine leukemia viruses (MuLV). Using the endogenous reverse transcriptase reaction of VL30 RNA-containing MuLV particles, full-length VL30 DNA was synthesized and cloned in pAT153. Analysis of a number of clones identified long terminal repeat structures (LTRs) characteristic of retrovirus proviruses and transposable genetic elements. Whilst the unique region of all clones was identical, the LTRs displayed some heterogeneity. Comparison of the unique region of cloned VL30 DNA with mouse genomic VL30 sequences showed the retrovirus-derived clones to be encoded by only a few members of the divergent VL30 gene family. These findings thus demonstrate a method for cloning a defined sub-class of retrovirus-like cellular genes which are both transcriptionally active and transmissible by a retrovirus.

Biochemical characterization of a deleted Kirsten sarcoma virus genome. Brief report

A Kirsten sarcoma virus transformed mouse cell line was found to contain a deleted provirus. RNA from the virus produced by these cells was characterized by hybridisation protection oligonucleotide fingerprinting and was found to be a simple deletion.