Effect of the California tobacco control program on personal health care expenditures

Background

Large state tobacco control programs have been shown to reduce smoking and would be expected to affect health care costs. We investigate the effect of California''s large-scale tobacco control program on aggregate personal health care expenditures in the state.

Methods and Findings

Cointegrating regressions were used to predict (1) the difference in per capita cigarette consumption between California and 38 control states as a function of the difference in cumulative expenditures of the California and control state tobacco control programs, and (2) the relationship between the difference in cigarette consumption and the difference in per capita personal health expenditures between the control states and California between 1980 and 2004. Between 1989 (when it started) and 2004, the California program was associated with $86 billion (2004 US dollars) (95% confidence interval [CI] $28 billion to $151 billion) lower health care expenditures than would have been expected without the program. This reduction grew over time, reaching 7.3% (95% CI 2.7%–12.1%) of total health care expenditures in 2004.

Conclusions

A strong tobacco control program is not only associated with reduced smoking, but also with reductions in health care expenditures.     

Geospatial Analysis on the Distributions of Tobacco Smoking and Alcohol Drinking in India

Background

Tobacco smoking and binge alcohol drinking are two of the leading risk factors for premature mortality worldwide. In India, studies have examined the geographic distributions of tobacco smoking and alcohol drinking only at the state-level; sub-state variations and the spatial association between the two consumptions are poorly understood.

Methodology

We used data from the Special Fertility and Mortality Survey conducted in 1998 to examine the geographic distributions of tobacco smoking and alcohol drinking at the district and postal code levels. We used kriging interpolation to generate smoking and drinking distributions at the postal code level. We also examined spatial autocorrelations and identified spatial clusters of high and low prevalence of smoking and drinking. Finally, we used bivariate analyses to examine the spatial correlations between smoking and drinking, and between cigarette and bidi smoking.

Results

There was a high prevalence of any smoking in the central and northeastern states, and a high prevalence of any drinking in Himachal Pradesh, Arunachal Pradesh, and eastern Madhya Pradesh. Spatial clusters of early smoking (started smoking before age 20) were identified in the central states. Cigarette and bidi smoking showed distinctly different geographic patterns, with high levels of cigarette smoking in the northeastern states and high levels of bidi smoking in the central states. The geographic pattern of bidi smoking was similar to early smoking. Cigarette smoking was spatially associated with any drinking. Smoking prevalences in 1998 were correlated with prevalences in 2004 at the district level and 2010 at the state level.

Conclusion

These results along with earlier evidence on the complementarities between tobacco smoking and alcohol drinking suggest that local public health action on smoking might also help to reduce alcohol consumption, and vice versa. Surveys that properly represent tobacco and alcohol consumptions at the district level are recommended.     

Prevalence of Tobacco Use in Urban,Semi Urban and Rural Areas in and around Chennai City,India

Background

Tobacco use leads to many health complications and is a risk factor for the occurrence of cardio vascular diseases, lung and oral cancers, chronic bronchitis etc. Almost 6 million people die from tobacco-related causes every year. This study was conducted to measure the prevalence of tobacco use in three different areas around Chennai city, south India.

Methods

A survey of 7510 individuals aged > = 15 years was undertaken covering Chennai city (urban), Ambattur (semi-urban) and Sriperumbudur (rural) taluk. Details on tobacco use were collected using a questionnaire adapted from both Global Youth Tobacco Survey and Global Adults Tobacco Survey.

Results

The overall prevalence of tobacco use was significantly higher in the rural (23.7%) compared to semi-urban (20.9%) and urban (19.4%) areas (P value <0.001) Tobacco smoking prevalence was 14.3%, 13.9% and 12.4% in rural, semi-urban and urban areas respectively. The corresponding values for smokeless tobacco use were 9.5%, 7.0% and 7.0% respectively. Logistic regression analysis showed that the odds of using tobacco (with smoke or smokeless forms) was significantly higher among males, older individuals, alcoholics, in rural areas and slum localities. Behavioural pattern analysis of current tobacco users led to three groups (1) those who were not reached by family or friends to advice on harmful effects (2) those who were well aware of harmful effects of tobacco and even want to quit and (3) those are exposed to second hand/passive smoking at home and outside.

Conclusions

Tobacco use prevalence was significantly higher in rural areas, slum dwellers, males and older age groups in this region of south India. Women used mainly smokeless tobacco. Tobacco control programmes need to develop strategies to address the different subgroups among tobacco users. Public health facilities need to expand smoking cessation counseling services as well as provide pharmacotherapy where necessary.     

A mixture of begomoviruses in leaf curl-affected tobacco in Karnataka, South India

Tobacco leaf curl is widespread in several states in India including Andhra Pradesh, Gujarat, Karnataka, Bihar and West Bengal. Tobacco leaf curl virus (TbLCV) isolates collected from five different parts of India induced four distinct symptom phenotypes (group I, II, III & IV) on tobacco cultivars Samsun and Anand 119 (Valand & Muniyappa, 1992). PCR was performed on DNA extracted from group I and IV leaf curl‐affected tobacco from Karnataka, India using degenerate begomovirus‐specific primers. Subsequent cloning and sequencing of PCR products revealed preliminary evidence for the presence of at least three begomoviruses in the affected material following alignment of a 333 bp region of the coat protein gene (CP). The complete CP and common region (CR) of two putative begomoviruses, Tobacco leaf curl virus‐Karnataka1 (TbLCV‐Kar1) and Tobacco leaf curl virus‐Karnataka2 (TbLCV‐Kar2), were sequenced using PCR clones obtained with designed sequence‐specific primers. Phylogenetic analysis of the CP and CR of TbLCV‐Kar1 and TbLCV‐Kar2 placed them in the Asian Old World begomovirus cluster. The two viruses differed from each other significantly in both the CP gene and the CR (< 90% nucleotide sequence identity). This difference, in conjunction with distinct iterative sequences strongly suggests that these begomoviruses are distinct from one another. Group I and IV tobacco were also found to harbour a possible third begomovirus following the 333 bp CP alignment. Comparison of TbLCV‐Kar1 and TbLCV‐Kar2 with other geminiviruses, showed that both sequences shared high nucleotide sequence identity (> 90%) with other begomoviruses in either the CP or CR, thereby suggesting these viruses to be possible strains of other reported begomoviruses. Combined comparison of the CP and CR sequences however, suggests that the two viruses are not strains of other reported begomoviruses, but may be distinct begomoviruses that could have arisen through recombination events during mixed infections. Phylogenetic comparison demonstrated no significant homology between the Indian tobacco begomoviruses and a tobacco‐infecting begomovirus from Zimbabwe, again showing that as with other geminiviruses, there is a geographic basis for phylogenetic relationships rather than an affiliation with tobacco as a host.     

Effect of Exposure to Smoking in Movies on Young Adult Smoking in New Zealand

Onscreen Smoking Is a Form of Tobacco Marketing

Tobacco advertising has been prohibited in New Zealand since 1990, and the government has set a goal of becoming a smokefree nation by 2025. However, tobacco marketing persists indirectly through smoking in motion pictures, and there is strong evidence that exposure to onscreen smoking causes young people to start smoking. We investigated the relationship between exposure to smoking in movies and youth smoking initiation among New Zealand young adults. Data from an online survey of 419 smokers and non-smokers aged 18 to 25 were used to estimate respondents’ exposure to smoking occurrences in 50 randomly-selected movies from the 423 US top box office movies released between 2008 and 2012. Analyses involved calculating movie smoking exposure (MSE) for each respondent, using logistic regression to analyse the relationship between MSE and current smoking behaviour, and estimating the attributable fraction due to smoking in movies.

Effect of Smoking in Movies on New Zealand Youth

Exposure to smoking occurrences in movies was associated with current smoking status. After allowing for the influence of family, friends and co-workers, age and rebelliousness, respondents’ likelihood of smoking increased by 11% for every 100-incident increase in exposure to smoking incidents, (aOR1.11; p< .05). The estimated attributable fraction due to smoking in movies was 54%; this risk could be substantially reduced by eliminating smoking from movies currently rated as appropriate for youth. We conclude that exposure to smoking in movies remains a potent risk factor associated with smoking among young adults, even in a progressive tobacco control setting such as New Zealand. Harmonising the age of legal tobacco purchase (18) with the age at which it is legal to view smoking in movies would support New Zealand’s smokefree 2025 goal.     

Strategies for Tobacco Control in India: A Systematic Review

Background

Tobacco control needs in India are large and complex. Evaluation of outcomes to date has been limited.

Aim

To review the extent of tobacco control measures, and the outcomes of associated trialled interventions, in India.

Methods

Information was identified via database searches, journal hand-searches, reference and citation searching, and contact with experts. Studies of any population resident in India were included. Studies where outcomes were not yet available, not directly related to tobacco use, or not specific to India, were excluded. Pre-tested proformas were used for data extraction and quality assessment. Studies with reliability concerns were excluded from some aspects of analysis. The Framework Convention on Tobacco Control (FCTC) was use as a framework for synthesis. Heterogeneity limited meta-analysis options. Synthesis was therefore predominantly narrative.

Results

Additional to the Global Tobacco Surveillance System data, 80 studies were identified, 45 without reliability concerns. Most related to education (FCTC Article 12) and tobacco-use cessation (Article 14). They indicated widespread understanding of tobacco-related harm, but less knowledge about specific consequences of use. Healthcare professionals reported low confidence in cessation assistance, in keeping with low levels of training. Training for schoolteachers also appeared suboptimal. Educational and cessation assistance interventions demonstrated positive impact on tobacco use. Studies relating to smoke-free policies (Article 8), tobacco advertisements and availability (Articles 13 and 16) indicated increasingly widespread smoke-free policies, but persistence of high levels of SHS exposure, tobacco promotions and availability—including to minors. Data relating to taxation/pricing and packaging (Articles 6 and 11) were limited. We did not identify any studies of product regulation, alternative employment strategies, or illicit trade (Articles 9, 10, 15 and 17).

Conclusions

Tobacco-use outcomes could be improved by school/community-based and adult education interventions, and cessation assistance, facilitated by training for health professionals and schoolteachers. Additional tobacco control measures should be assessed.     

Corporate Philanthropy,Political Influence,and Health Policy

Background

The Framework Convention of Tobacco Control (FCTC) provides a basis for nation states to limit the political effects of tobacco industry philanthropy, yet progress in this area is limited. This paper aims to integrate the findings of previous studies on tobacco industry philanthropy with a new analysis of British American Tobacco''s (BAT) record of charitable giving to develop a general model of corporate political philanthropy that can be used to facilitate implementation of the FCTC.

Method

Analysis of previously confidential industry documents, BAT social and stakeholder dialogue reports, and existing tobacco industry document studies on philanthropy.

Results

The analysis identified six broad ways in which tobacco companies have used philanthropy politically: developing constituencies to build support for policy positions and generate third party advocacy; weakening opposing political constituencies; facilitating access and building relationships with policymakers; creating direct leverage with policymakers by providing financial subsidies to specific projects; enhancing the donor''s status as a source of credible information; and shaping the tobacco control agenda by shifting thinking on the importance of regulating the market environment for tobacco and the relative risks of smoking for population health. Contemporary BAT social and stakeholder reports contain numerous examples of charitable donations that are likely to be designed to shape the tobacco control agenda, secure access and build constituencies.

Conclusions and Recommendations

Tobacco companies'' political use of charitable donations underlines the need for tobacco industry philanthropy to be restricted via full implementation of Articles 5.3 and 13 of the FCTC. The model of tobacco industry philanthropy developed in this study can be used by public health advocates to press for implementation of the FCTC and provides a basis for analysing the political effects of charitable giving in other industry sectors which have an impact on public health such as alcohol and food.     

烟草内生细菌防治烟草黑胫病及促生作用研究

筛选烟草内生细菌防治烟草黑胫病, 获得了对烟草黑胫病有很好防效的内生细菌118、57和93等菌株。在温室控病实验中它们的防效分别可达69.23%、61.53%和65.38%。118菌株对烟草疫霉(Phytophthora parasitica var. nicotianae)菌丝生长有明显的拮抗作用。118菌株具有较广的抗菌谱, 且对烟草有促生效果, 烟草的鲜重增产率为13.10%。     

Definitions of state variables and state space for brain–computer interface

The hypothesis is proposed that the central dynamics of the action–perception cycle has five steps: emergence from an existing macroscopic brain state of a pattern that predicts a future goal state; selection of a mesoscopic frame for action control; execution of a limb trajectory by microscopic spike activity; modification of microscopic cortical spike activity by sensory inputs; construction of mesoscopic perceptual patterns; and integration of a new macroscopic brain state. The basis is the circular causality between microscopic entities (neurons) and the mesoscopic and macroscopic entities (populations) self-organized by axosynaptic interactions. Self-organization of neural activity is bidirectional in all cortices. Upwardly the organization of mesoscopic percepts from microscopic spike input predominates in primary sensory areas. Downwardly the organization of spike outputs that direct specific limb movements is by mesoscopic fields constituting plans to achieve predicted goals. The mesoscopic fields in sensory and motor cortices emerge as frames within macroscopic activity. Part 1 describes the action–perception cycle and its derivative reflex arc qualitatively. Part 2 describes the perceptual limb of the arc from microscopic MSA to mesoscopic wave packets, and from these to macroscopic EEG and global ECoG fields that express experience-dependent knowledge in successive states. These macroscopic states are conceived to embed and control mesoscopic frames in premotor and motor cortices that are observed in local ECoG and LFP of frontoparietal areas. The fields sampled by ECoG and LFP are conceived as local patterns of neural activity in which trajectories of multiple spike activities (MSA) emerge that control limb movements. Mesoscopic frames are located by use of the analytic signal from the Hilbert transform after band pass filtering. The state variables in frames are measured to construct feature vectors by which to describe and classify frame patterns. Evidence is cited to justify use of linear analysis. The aim of the review is to enable researchers to conceive and identify goal-oriented states in brain activity for use as commands, in order to relegate the details of execution to adaptive control devices outside the brain. http://sulcus.berkeley.edu     

Calf venous compliance in multiple system atrophy

In multiple system atrophy (MSA), increased venous compliance with excessive venous pooling is assumed to be a major contributor to orthostatic hypotension (OH); however, venous compliance has never been assessed in MSA patients. We evaluated the severity and distribution of adrenergic, cardiovagal, and sudomotor failure in 11 patients with probable MSA, 14 age- and sex-matched control subjects, and 8 patients with Parkinson's disease (PD) but not OH. Calf venous compliance, venous filling, and capillary filtration were measured using calf plethysmography. The response to the directly acting alpha-adrenergic stimulation (10 mg midodrine) on calf venous compliance was additionally evaluated. Contrary to our hypothesis, pressure-volume curves in the legs of MSA patients were flatter than in PD patients (P < 0.05) or controls (P < 0.001); this indicated reduced calf venous compliance in MSA. The MSA group had reduced venous filling compared with control (P < 0.001) or PD subjects (P < 0.001) but had a normal capillary filtration rate (P = 0.73). Direct alpha-adrenergic stimulation resulted in a slight but significant reduction of calf venous compliance in controls (P = 0.001) and PD subjects (P < 0.001) but not in the MSA group. The compliance change in MSA significantly regressed with autonomic failure (composite autonomic severity scale, r(2) = 0.56) but not with parkinsonism (Unified MSA Rating Scale, r(2) = 0.12). Our data indicate that MSA patients with chronic OH have reduced, rather than increased, venous compliance in the lower leg. We postulate that chronic venous distension that is associated with OH results in structural remodeling of veins, leading to reduced compliance, a change which may protect patients against orthostatic stress.     

Tobacco smoke induces mitochondrial depolarization along with cell death: effects of antioxidants

Smoking has been associated with a large number of diseases, in particular cancers. Among the many substances identified in tobacco smoke, reactive oxygen species (ROS) are major carcinogens. We have previously reported that exposure of mammalian cells to tobacco smoke induces the expression of stress proteins, as well as apoptosis (programmed cell death). Here we examined the effects of tobacco smoke on mitochondrial membrane potential (deltapsim), since mitochondria have been proposed to control the effector phase of apoptosis. We used normal human monocytes for these experiments, with the prospect for application of deltapsim as a biomarker of oxidative stress. Tobacco smoke induced mitochondrial depolarization at 3 h, and apoptosis (or necrosis for higher concentrations) after 16 h. Apoptosis was assessed by both a functional approach (annexin V binding) and morphological analysis (electron microscopy). N-acetyl-cysteine prevented tobacco smoke-induced deltapsim disruption and apoptosis, while the caspase inhibitor Z-VAD.Fmk did not affect deltapsim, though preventing apoptosis, and superoxide dismutase had no effect. Our data designate mitochondria as a target for ROS-mediated effects of tobacco smoke exposure.     

Age at start of using tobacco on the risk of head and neck cancer: Pooled analysis in the International Head and Neck Cancer Epidemiology Consortium (INHANCE)

BackgroundTobacco use is a well-established risk factor for head and neck cancer (HNC). However, less is known about the potential impact of exposure to tobacco at an early age on HNC risk.MethodsWe analyzed individual-level data on ever tobacco smokers from 27 case-control studies (17,146 HNC cases and 17,449 controls) in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using random-effects logistic regression models.ResultsWithout adjusting for tobacco packyears, we observed that younger age at starting tobacco use was associated with an increased HNC risk for ever smokers (OR_{<10 years vs. ≥30 years}: 1.64, 95% CI: 1.35, 1.97). However, the observed association between age at starting tobacco use and HNC risk became null after adjusting for tobacco packyears (OR_{<10 years vs. ≥30 years}: 0.97, 95% CI: 0.80, 1.19). In the stratified analyses on HNC subsites by tobacco packyears or years since quitting, no difference in the association between age at start and HNC risk was observed.ConclusionsResults from this pooled analysis suggest that increased HNC risks observed with earlier age at starting tobacco smoking are largely due to longer duration and higher cumulative tobacco exposures.     

Smoking or My Job? US Media Coverage of Nonsmoker-Only Hiring Policies

Objectives

Media advocacy plays a critical role in tobacco control, shaping the content of news in ways that generate public support for tobacco control. We examined US media coverage of nonsmoker-only hiring policies, which have little US public support, exploring the extent to which tobacco control advocates and experts have engaged the media on this controversial issue.

Methods

We searched online media databases (Lexis Nexis, Access World News, and Proquest) for articles published from 1995–2013, coding retrieved items through a collaborative, iterative process. We analyzed the volume, type, provenance, prominence, content and slant of coverage.

Results

We found 1,159 media items on nonsmoker-only hiring policies, most published in local newspapers in regions where such policies were enacted. The most common reason given for implementing such policies was to reduce healthcare costs. Most news items offered reasons both to support and oppose such policies; thus, the slant of the majority of news items was neutral or mixed. Tobacco control advocates or experts were infrequently cited or quoted in news items, and rarely authored opinion pieces. Those who expressed opinions were more likely to support than oppose nonsmoker-only hiring policies, for economic and health reasons. Ethical concerns about the policies were seldom raised.

Conclusions

As presented in the media, nonsmoker-only hiring policies were primarily framed in terms of business cost savings and had little connection to health initiatives. Tobacco control advocates were rarely quoted and their positions were not consistent. Given their intrusiveness and the lack of strong evidence that such business policies actually do improve worker health, tobacco control advocates may feel that the status quo is preferable to engaging on a policy that the majority of Americans dislike.     

Tobacco Industry Manipulation of Tobacco Excise and Tobacco Advertising Policies in the Czech Republic: An Analysis of Tobacco Industry Documents

Background

The Czech Republic has one of the poorest tobacco control records in Europe. This paper examines transnational tobacco companies'' (TTCs'') efforts to influence policy there, paying particular attention to excise policies, as high taxes are one of the most effective means of reducing tobacco consumption, and tax structures are an important aspect of TTC competitiveness.

Methods and Findings

TTC documents dating from 1989 to 2004/5 were retrieved from the Legacy Tobacco Documents Library website, analysed using a socio-historical approach, and triangulated with key informant interviews and secondary data. The documents demonstrate significant industry influence over tobacco control policy. Philip Morris (PM) ignored, overturned, and weakened various attempts to restrict tobacco advertising, promoting voluntary approaches as an alternative to binding legislation. PM and British American Tobacco (BAT) lobbied separately on tobacco tax structures, each seeking to implement the structure that benefitted its own brand portfolio over that of its competitors, and enjoying success in turn. On excise levels, the different companies took a far more collaborative approach, seeking to keep tobacco taxes low and specifically to prevent any large tax increases. Collective lobbying, using a variety of arguments, was successful in delaying the tax increases required via European Union accession. Contrary to industry arguments, data show that cigarettes became more affordable post-accession and that TTCs have taken advantage of low excise duties by raising prices. Interview data suggest that TTCs enjoy high-level political support and continue to actively attempt to influence policy.

Conclusion

There is clear evidence of past and ongoing TTC influence over tobacco advertising and excise policy. We conclude that this helps explain the country''s weak tobacco control record. The findings suggest there is significant scope for tobacco tax increases in the Czech Republic and that large (rather than small, incremental) increases are most effective in reducing smoking. Please see later in the article for the Editors'' Summary     

Specific features of oxidative stress in the chilled tobacco plants following transformation with the desC gene for acyl-lipid Δ9-desaturase from Synechococcus vulcanus

Tobacco plants (Nicotiana tabacum L.) transformed with the desC gene for acyl-lipid Δ9-desaturase from a thermophilic cyanobacterium Synechococcus vulcanus were cultivated on the agarized Murashige and Skoog medium at 22°C and a 16-h photoperiod. Tobacco plants transformed with an empty binary vector pGA482 served as the control. The investigations showed that, in contrast to the control, transgenic plants maintained a higher activity of antioxidant enzymes during 2-h incubation at 2°C; as a result, these plants resisted more efficiently the accumulation of reactive oxygen species and reduced the rate of the lipid peroxidation. The activity of antioxidant enzymes in the transformed plants is apparently related to the operation of the introduced desC gene for acyl-lipid Δ9-desaturase because the enhanced activity of the latter increased the relative content of polyunsaturated FAs in membrane lipids and in this way promoted the liquid state of membranes during the chilling period. These changes helped preserve the cellular homeostasis and thereby maintain the steady synthesis of antioxidant enzymes at hypothermic conditions; as a result, cold resistance of transformed tobacco plants increased.     

Parental Smoking in the Vicinity of Children and Tobacco Control Policies in the European Region

Objective

To ascertain patterns of parental smoking in the vicinity of children in Eastern and Western Europe and their relation to Tobacco Control Scale (TCS) scores.

Methods

Data on parental smoking patterns were obtained from the School Child Mental Health Europe (SCMHE), a 2010 cross-sectional survey of 5141 school children aged 6 to 11 years and their parents in six countries: Germany, Netherlands, Lithuania, Romania, Bulgaria and Turkey ranked by TCS into three level categories toward tobacco control policies.

Results

A slightly higher proportion of Eastern compared to Western European mothers (42.4 vs. 35.1%) were currently smoking in but the difference was not statistically significant after adjusting for maternal age and maternal educational attainment. About a fifth (19.3%) and a tenth (10.0%) of Eastern and Western European mothers, respectively, smoked in the vicinity of their children, and the difference was significant even after adjustment for potential confounders (p<0.001). Parents with the highest educational attainment were significantly less likely to smoke in the vicinity of their children than those with the lowest attainment. After control of these covariates lax tobacco control policies, compared to intermediate policies, were associated with a 50% increase in the likelihood of maternal smoking in the vicinity of children adjusted odds ratio (AOR) = 1.52 and 1.64. Among fathers, however, the relationship with paternal smoking and TCS seems more complex since strict policy increases the risk as well AOR = 1,40. Only one country, however belongs to the strict group.

Significance

Tobacco control policies seem to have influenced maternal smoking behaviors overall to a limited degree and smoking in the vicinity of children to a much greater degree. Children living in European countries with lax tobacco control policies are more likely to be exposed to second hand smoking from maternal and paternal smoking.     

中国烟草种质资源分发利用情况分析

烟草种质资源是烟草新品种选育、遗传理论研究、生物技术研究和烟叶生产的宝贵资源和重要战略物资,也是我国烟草行业能否健康快速发展的关键所在。本文详细统计分析了1983-2014年这32年间我国烟草种质资源的分发利用情况,尤其是自2007年国家烟草专卖局正式启动"中国烟草种质资源平台建设"专项以来我国烟草种质资源的利用效果。阐述了当前我国烟草种质资源收集保存和利用研究上存在的问题,并提出了今后加强完善我国烟草种质资源工作的相关对策。旨在为我国烟草种质资源的进一步收集、保存以及更加全面充分的利用提供理论和应用基础。     

The Systemic Infection by Tobacco Mosaic Virus of Tobacco Plants Coutaining the N Gene at Temperatures Below 28°C

Tobacco plants containing the N-gene are occasionally systemically infected with tobacco mosaic virus (TMV) at tempreratures below 28°C, but contain low concentrations of virus: they often fail to set seed, and can outlive healthy control plants. Infection is thus similar to that induced when N-gene tobacco plants are grafted onto systemically infected tobacco lacking the N-gene. Shoots from systemically infected N-gene plants can induce systemic infection in other graft-inoculated N-gene plants. Stem sections of N-gene tobacco plants act as good conduits for TMV between plants lacking the N-gene, and girdling experiments suggest that virus movement probably occurs in the phloern.