Vascular microphysiological systems.

PURPOSE OF REVIEW: This review summarizes innovations in vascular microphysiological systems (MPS) and discusses the themes that have emerged from recent works. RECENT FINDINGS: Vascular MPS are increasing in complexity and ability to replicate tissue. Many labs use vascular MPS to study transport phenomena such as analyzing endothelial barrier function. Beyond vascular permeability, these models are also being used for pharmacological studies, including drug distribution and toxicity modeling. In part, these studies are made possible due to exciting advances in organ-specific models. Inflammatory processes have also been modeled by incorporating immune cells, with the ability to explore both cell migration and function. Finally, as methods for generating vascular MPS flourish, many researchers have turned their attention to incorporating flow to more closely recapitulate in vivo conditions. SUMMARY: These models represent many different types of tissue and disease states. Some devices have relatively simple geometry and few cell types, while others use complex, multicompartmental microfluidics and integrate several cell types and origins. These 3D models enable us to observe model evolution in real time and perform a plethora of functional assays not possible using traditional cell culture methods.

Preoperative cesarean delivery intravenous acetaminophen treatment for postoperative pain control: a randomized double-blinded placebo control trial.

BACKGROUND: The United States currently has an opioid use disorder epidemic and research evaluating ways to minimize the use of opioids postsurgery are needed. One of these options is intravenous acetaminophen. If the use of preoperative intravenous acetaminophen was found to be effective for cesarean delivery, this would be beneficial for both the mother and breast-feeding neonate. OBJECTIVE: The primary study objective was to see if maternal opioid use was significantly less in the postoperative period for the study group that received 1 g of intravenous acetaminophen preoperatively compared with a control group that received placebo. The secondary objectives were to evaluate maternal length of stay and pain scores postoperatively, and assess the acetaminophen level in cord blood at delivery. STUDY DESIGN: This study was a prospective double-blinded randomized placebo-controlled trial. All pregnant patients who entered labor and delivery for a scheduled cesarean from November 2015 through April 2017 were eligible. Once consented, the medication was supplied by the pharmacy department, which performed the blinded randomization. Both the study drug of 1000 mg (1 g) of acetaminophen and placebo of normal saline were distributed as unmarked 100-mL bags administered over 15 minutes just prior to incision. No study personnel from the obstetric or anesthesia departments had any access to the randomization. Based on a power analysis using the published surgical data results, the goal was to obtain a minimum of 100 patients (50 patients in each arm). Primary data collection included demographics, number of opioid doses and morphine milligram equivalents administered to the patient postoperatively, length of stay postdelivery, pain scores, and newborn cord blood acetaminophen levels. Exclusions were maternal acetaminophen allergy, receipt of acetaminophen in the prior 24 hours, opioid use disorder, and hepatitis/liver impairment. Statistics involved χ2, Fisher exact, and the Student t test where appropriate and a P value <.05 was considered significant with all tests considered against a 2-sided alternative hypothesis. RESULTS: A total of 105 patients were evaluated with 51 who received intravenous acetaminophen and 54 who received placebo. The number of postoperative opioid medication doses administered to the study group was 11.1 (±8.9) compared with the number received by the control group of 10.5 (±8.5), P = .72. The morphine milligram equivalents in the study group was 94.2 (±40.4) compared with the control group of 90.7 (±42.1), P = .67. The length of stay and pain scores were not different between the groups. All of the umbilical cord blood values for acetaminophen were subtherapeutic. CONCLUSION: These data demonstrate that for cesarean delivery, the use of a preoperative 1-g intravenous dose of acetaminophen does not decrease the number of opioid medication doses or the morphine milligram equivalents administered postoperatively, nor does it decrease length of stay postcesarean. The administration of 1-g intravenous acetaminophen preoperatively does not result in elevated newborn cord blood levels (ClinicalTrials.govNCT02694653).

Linking cell mechanical memory and cancer metastasis.

Metastasis causes most cancer-related deaths; however, the efficacy of anti-metastatic drugs is limited by incomplete understanding of the biological mechanisms that drive metastasis. Focusing on the mechanics of metastasis, we propose that the ability of tumour cells to survive the metastatic process is enhanced by mechanical stresses in the primary tumour microenvironment that select for well-adapted cells. In this Perspective, we suggest that biophysical adaptations favourable for metastasis are retained via mechanical memory, such that the extent of memory is influenced by both the magnitude and duration of the mechanical stress. Among the mechanical cues present in the primary tumour microenvironment, we focus on high matrix stiffness to illustrate how it alters tumour cell proliferation, survival, secretion of molecular factors, force generation, deformability, migration and invasion. We particularly centre our discussion on potential mechanisms of mechanical memory formation and retention via mechanotransduction and persistent epigenetic changes. Indeed, we propose that the biophysical adaptations that are induced by this process are retained throughout the metastatic process to improve tumour cell extravasation, survival and colonization in the distant organ. Deciphering mechanical memory mechanisms will be key to discovering a new class of anti-metastatic drugs.

Transmural Flow Upregulates PD-L1 Expression in Microvascular Networks.

Endothelial programmed death-ligand 1 (PD-L1) expression is higher in tumors than in normal tissues. Also, tumoral vasculatures tend to be leakier than normal vessels leading to a higher trans-endothelial or transmural fluid flow. However, it is not clear whether such elevated transmural flow can control endothelial PD-L1 expression. Here, a new microfluidic device is developed to investigate the relationship between transmural flow and PD-L1 expression in microvascular networks (MVNs). After treating the MVNs with transmural flow for 24 h, the expression of PD-L1 in endothelial cells is upregulated. Additionally, CD8 T cell activation by phytohemagglutinin (PHA) is suppressed when cultured in the MVNs pre-conditioned with transmural flow. Moreover, transmural flow is able to further increase PD-L1 expression in the vessels formed in the tumor microenvironment. Finally, by utilizing blocking antibodies and knock-out assays, it is found that transmural flow-driven PD-L1 upregulation is controlled by integrin αVß3. Overall, this study provides a new biophysical explanation for high PD-L1 expression in tumoral vasculatures.

Impact of Fibrinogen, Fibrin Thrombi, and Thrombin on Cancer Cell Extravasation Using In Vitro Microvascular Networks.

A bidirectional association exists between metastatic dissemination and the hypercoagulable state associated with many types of cancer. As such, clinical studies have provided evidence that markers associated with elevated levels of coagulation and fibrinolysis correlate with decreased patient survival. However, elucidating the mechanisms underpinning the effects of different components of the coagulation system on metastasis formation is challenging both in animal models and 2D models lacking the complex cellular interactions necessary to model both thrombosis and metastasis. Here, an in vitro, 3D, microvascular model for observing the formation of fibrin thrombi is described, which is in turn used to study how different aspects of the hypercoagulable state associated with cancer affect the endothelium. Using this platform, cancer cells expressing ICAM-1 are shown to form a fibrinogen-dependent bridge and transmigrate through the endothelium more effectively. Cancer cells are also demonstrated to interact with fibrin thrombi, using them to adhere, spread, and enhance their extravasation efficiency. Finally, thrombin is also shown to enhance cancer cell extravasation. This system presents a physiologically relevant model of fibrin clot formation in the human microvasculature, enabling in-depth investigation of the cellular interactions between cancer cells and the coagulation system affecting cancer cell extravasation.

Development of a perfusable, hierarchical microvasculature-on-a-chip model.

Several methods have been developed for generating 3D, in vitro, organ-on-chip models of human vasculature to study vascular function, transport, and tissue engineering. However, many of these existing models lack the hierarchical nature of the arterial-to-capillary-to-venous architecture that is key to capturing a more comprehensive view of the human microvasculature. Here, we present a perfusable, multi-compartmental model that recapitulates the three microvascular compartments to assess various physiological properties such as vessel permeability, vasoconstriction dynamics, and circulating cell arrest and extravasation. Viscous finger patterning and passive pumping create the larger arterial and venular lumens, while the smaller diameter capillary bed vessels are generated through self-assembly. These compartments anastomose and form a perfusable, hierarchical system that portrays the directionality of blood flow through the microvasculature. The addition of collagen channels reduces the apparent permeability of the central capillary region, likely by reducing leakage from the side channels, enabling more accurate measurements of vascular permeability-an important motivation for this study. Furthermore, the model permits modulation of fluid flow and shear stress conditions throughout the system by using hydrostatic pressure heads to apply pressure differentials across either the arteriole or the capillary. This is a pertinent system for modeling circulating tumor or T cell dissemination and extravasation. Circulating cells were found to arrest in areas conducive to physical trapping or areas with the least amount of shear stress, consistent with hemodynamic or mechanical theories of metastasis. Overall, this model captures more features of human microvascular beds and is capable of testing a broad variety of hypotheses.

Application of Size Exclusion Chromatography with Multiangle Light Scattering in the Analytical Development of a Preclinical Stage Gene Therapy Program.

To provide safe recombinant adeno-associated viruses (rAAV) to patients, scalable manufacturing processes are required. However, these processes may introduce impurities that impact the performance and quality of the final drug product. Empty rAAV capsids are product-related impurities. Regulatory guidance requires that accurate analytical methods be implemented early in product development to measure the level of empty capsids. A process confirmation vector, produced from 200 L production, was used to develop and optimize a size exclusion chromatography with UV and multiangle light scattering (SEC-MALS) method. Vector produced from a 500 L production was used to assess the full-to-empty ratio using the following analytical methods: sedimentation velocity analytical ultracentrifugation (SV-AUC), droplet digital PCR (ddPCR) with capsid enzyme-linked immunosorbent assay (ELISA), bulk absorbance at 260/280 nm, cryogenic electron microscopy, and SEC-MALS. This test article was used for a 30-day, non-Good Laboratory Practices animal study that assessed biodistribution of the product (STRX-330). SEC-MALS outperformed the other methods and correlated well with SV-AUC values of full-to-empty particles. In addition, SEC-MALS agreed with ddPCR and ELISA measurements for vector genomes/mL and capsid particles/mL, respectively. SEC-MALS was linear, accurate, and precise while achieving chromatography quality control (QC) recommendations. Compared to other stability-indicating assays, SEC-MALS performed similarly to ddPCR, capsid ELISA, and infectivity assays in accelerated stress studies. In response to alkaline, but not acidic stress, SEC-MALS indicated distinct changes in the DNA content of the monomer Adeno-associated viruses (AAV) peak for STRX-330, which was supported by ddPCR data. Conversely, acidic treatment resulted in more aggregated vector, but did not impact the DNA content. This work indicates that SEC-MALS is a valuable analytical tool in the analytical development and QC testing of AAV. In addition, this work suggests that SEC-MALS can provide fundamental understanding of AAV in response to environmental stress. This may impact steps of the manufacturing process to minimize conditions that reduce performance.

New Strategy for Promoting Vascularization in Tumor Spheroids in a Microfluidic Assay.

Previous studies have developed vascularized tumor spheroid models to demonstrate the impact of intravascular flow on tumor progression and treatment. However, these models have not been widely adopted so the vascularization of tumor spheroids in vitro is generally lower than vascularized tumor tissues in vivo. To improve the tumor vascularization level, a new strategy is introduced to form tumor spheroids by adding fibroblasts (FBs) sequentially to a pre-formed tumor spheroid and demonstrate this method with tumor cell lines from kidney, lung, and ovary cancer. Tumor spheroids made with the new strategy have higher FB densities on the periphery of the tumor spheroid, which tend to enhance vascularization. The vessels close to the tumor spheroid made with this new strategy are more perfusable than the ones made with other methods. Finally, chimeric antigen receptor (CAR) T cells are perfused under continuous flow into vascularized tumor spheroids to demonstrate immunotherapy evaluation using vascularized tumor-on-a-chip model. This new strategy for establishing tumor spheroids leads to increased vascularization in vitro, allowing for the examination of immune, endothelial, stromal, and tumor cell responses under static or flow conditions.

Priming a vascular-selective cytokine response permits CD8+ T-cell entry into tumors.

Targeting DNA methyltransferase 1 (DNMT1) has immunomodulatory and anti-neoplastic activity, especially when paired with cancer immunotherapies. Here we explore the immunoregulatory functions of DNMT1 in the tumor vasculature of female mice. Dnmt1 deletion in endothelial cells (ECs) impairs tumor growth while priming expression of cytokine-driven cell adhesion molecules and chemokines important for CD8+ T-cell trafficking across the vasculature; consequently, the efficacy of immune checkpoint blockade (ICB) is enhanced. We find that the proangiogenic factor FGF2 promotes ERK-mediated DNMT1 phosphorylation and nuclear translocation to repress transcription of the chemokines Cxcl9/Cxcl10 in ECs. Targeting Dnmt1 in ECs reduces proliferation but augments Th1 chemokine production and extravasation of CD8+ T-cells, suggesting DNMT1 programs immunologically anergic tumor vasculature. Our study is in good accord with preclinical observations that pharmacologically disrupting DNMT1 enhances the activity of ICB but suggests an epigenetic pathway presumed to be targeted in cancer cells is also operative in the tumor vasculature.

Engineering microvascular networks using a KLF2 reporter to probe flow-dependent endothelial cell function.

Shear stress generated by the flow of blood in the vasculature is a potent regulator of endothelial cell phenotype and vascular structure. While vascular responses to flow are complex and context-dependent, endothelial cell signaling in response to shear stress induced by laminar flows is coordinated by the transcription factor KLF2. The expression of KLF2 in endothelial cells is associated with a quiescent, anti-inflammatory phenotype and has been well characterized in two-dimensional systems, but has not been studied in three-dimensional in vitro systems. Here we develop engineered microvascular networks (MVNs) with a KLF2-based endothelial cell sensor within a microfluidic chip, apply continuous flow using an attached microfluidic pump, and study the effects of this flow on vascular structure and function. We found that culture of MVNs exposed to flow for 48 hours that resulted in increased expression of the KLF2-GFP-reporter display larger vessel diameters and decreased vascular branching and resistance. Additionally, vessel diameters after the application of flow were independent of initial MVN morphologies. Finally, we found that MVNs exposed to flow have improved vascular barrier function and decreased platelet adhesion. The MVNs with KLF2-based flow sensors represent a powerful tool for evaluating the structural and functional effects of flow on engineered three-dimensional vascular systems.

Engineered Microphysiological Systems for Testing Effectiveness of Cell-Based Cancer Immunotherapies.

Cell therapies, including adoptive immune cell therapies and genetically engineered chimeric antigen receptor (CAR) T or NK cells, have shown promise in treating hematologic malignancies. Yet, immune cell infiltration and expansion has proven challenging in solid tumors due to immune cell exclusion and exhaustion and the presence of vascular barriers. Testing next-generation immune therapies remains challenging in animals, motivating sophisticated ex vivo models of human tumor biology and prognostic assays to predict treatment response in real-time while comprehensively recapitulating the human tumor immune microenvironment (TIME). This review examines current strategies for testing cell-based cancer immunotherapies using ex vivo microphysiological systems and microfluidic technologies. Insights into the multicellular interactions of the TIME will identify novel therapeutic strategies to help patients whose tumors are refractory or resistant to current immunotherapies. Altogether, these microphysiological systems (MPS) have the capability to predict therapeutic vulnerabilities and biological barriers while studying immune cell infiltration and killing in a more physiologically relevant context, thereby providing important insights into fundamental biologic mechanisms to expand our understanding of and treatments for currently incurable malignancies.

Preclinical models for development of immune-oncology therapies.

Immunotherapy has demonstrated great success in clinical treatment, especially for cancer care. Here we review preclinical models, including cell lines, three dimensional (3D) cultures, and mouse models to support the need for tools enabling the development of novel immune-oncology (I-O) therapies. While in vitro studies have the advantage of being relatively simpler, faster, and higher throughput than in vivo models, they must be designed carefully to recapitulate the biological conditions that influence drug efficacy. The growing prevalence of 3D in vitro and ex vivo models has enabled screening and mechanistic studies in more complex, tissue-like environments containing multiple interacting cell types. On the other hand, syngeneic mouse models have been instrumental in the historical development of immunotherapies and remain an important tool in drug development, despite lacking fidelity to certain aspects of human physiology and pathology. Xenograft and humanized mouse models address some of these challenges, yet present limitations of their own. Successful development and translation of new I-O therapies will likely require thoughtful combination of several of these preclinical models, and we aim to help research and development scientists utilize the appropriate tools and technologies to facilitate rapid transition from preclinical evaluation to clinical trials.

A Robust Method for Perfusable Microvascular Network Formation In Vitro.

Micropost-based microfluidic devices are widely used for microvascular network (MVN) formation in diverse research fields. However, consistently generating perfusable MVNs of physiological morphology and dimension has proven to be challenging. Here, how initial seeding parameters determine key characteristics of MVN formation is investigated and a robust two-step seeding strategy to generate perfusable physiological MVNs in microfluidic devices is established.

Toward a new predoctoral model: Education and training in clinical psychopharmacology.

A ubiquitous research finding in regional and national studies is that at least 40% of persons with mental disorders cannot access mental health services, and pharmacotherapy in particular. The American Psychological Association's (APA) designated programs for the provision of education and training in clinical psychopharmacology can be of great help in alleviating this national need. We address key developments relevant to the foundation of a predoctoral model of clinical psychopharmacology education and training. To this end, an overview of the Master of Science in Clinical Psychopharmacology (MSCP) program at The Chicago School of Professional Psychology (TCSPP) is presented. TCSPP is now enrolling its eleventh consecutive cohort of MSCP students, many of whom are doctoral students who are concurrently attending various APA accredited Health Service Psychology (HSP) programs. We provide two predoctoral routes for completing MSCP training: (a) a route allowing for the creation of concentrations in clinical psychopharmacology in Health Service Psychology (HSP) doctoral programs, providing up to half of MSCP coursework; and (b) a joint doctoral PsyD or PhD/MSCP program meeting APA accreditation and designation standards integrated into a 5-year curriculum to impart HSP graduates with the competencies to provide both psychotherapy and pharmacotherapy. We conclude with a discussion about the future direction of predoctoral clinical psychopharmacology education and training. Given its emphasis on neuroscience and interdisciplinary health care, such curricular models may help to address the nation's immediate mental health care needs, while serving to enhance the sustainability of HSP education and professional practice in the 21st Century. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Demographic and geographic differences in exposure to secondhand smoke in Missouri workplaces, 2007-2008.

INTRODUCTION: African Americans, Hispanics, service and blue-collar workers, and residents of rural areas are among those facing higher rates of workplace secondhand smoke exposure in states without smokefree workplace laws. Consequently, these groups also experience more negative health effects resulting from secondhand smoke exposure. The objective of this study was to examine disparities in workplace secondhand smoke exposure in a state without a comprehensive statewide smokefree workplace law and to use this information in considering a statewide law. METHODS: We developed a logistic multilevel model by using data from a 2007-2008 county-level study to account for individual and county-level differences in workplace secondhand smoke exposure. We included sex, age, race, annual income, education level, smoking status, and rural or urban residence as predictors of workplace secondhand smoke exposure. RESULTS: Factors significantly associated with increased exposure to workplace secondhand smoke were male sex, lower education levels, lower income, living in a small rural or isolated area, and current smoking. For example, although the overall rate of workplace exposure in Missouri is 11.5%, our model predicts that among young white men with low incomes and limited education living in small rural areas, 40% of nonsmokers and 56% of smokers may be exposed to secondhand smoke at work. CONCLUSION: Significant disparities exist in workplace secondhand smoke exposure across Missouri. A statewide smokefree workplace law would protect all citizens from workplace secondhand smoke exposure.

Engineering approaches for studying immune-tumor cell interactions and immunotherapy.

This review describes recent research that has advanced our understanding of the role of immune cells in the tumor microenvironment (TME) using advanced 3D in vitro models and engineering approaches. The TME can hinder effective eradication of tumor cells by the immune system, but immunotherapy has been able to reverse this effect in some cases. However, patient-to-patient variability in response suggests that we require deeper understanding of the mechanistic interactions between immune and tumor cells to improve response and develop novel therapeutics. Reconstruction of the TME using engineered 3D models allows high-resolution observation of cell interactions while allowing control of conditions such as hypoxia, matrix stiffness, and flow. Moreover, patient-derived organotypic models are an emerging tool for prediction of drug efficacy. This review highlights the importance of modeling and understanding the immune TME and describes new tools for identifying new biological targets, drug testing, and strategies for personalized medicine.

Microheart: A microfluidic pump for functional vascular culture in microphysiological systems.

Advances in microphysiological systems have prompted the need for long-term cell culture under physiological flow conditions. Conventional laboratory pumps typically lack the ability to deliver cell culture media at the low flow rates required to meet the physiological ranges of fluid flow, and are often pulsatile or require flow reversal. Here, a microfluidic-based pump is presented, which allows for the controlled delivery of media for vascular microphysiological applications. The performance of the pump was characterized in a range of microfluidic systems, including straight channels of varying dimensions and self-assembled microvascular networks. A theoretical framework was developed based on lumped element analysis to predict the performance of the pump for different fluidic configurations and a finite element model of the included check-valves. The use of the pump for microvascular physiological studies demonstrated the utility of this system to recapitulate vascular fluid transport phenomena in microphysiological systems, which may find applications in disease models and drug screening.

A robust vasculogenic microfluidic model using human immortalized endothelial cells and Thy1 positive fibroblasts.

Human umbilical vein endothelial cells (HUVECs) and stromal cells, such as human lung fibroblasts (FBs), have been widely used to generate functional microvascular networks (µVNs) in vitro. However, primary cells derived from different donors have batch-to-batch variations and limited lifespans when cultured in vitro, which hampers the reproducibility of µVN formation. Here, we immortalize HUVECs and FBs by exogenously expressing human telomerase reverse transcriptase (hTERT) to obtain stable endothelial cell and FB sources for µVN formation in vitro. Interestingly, we find that immortalized HUVECs can only form functional µVNs with immortalized FBs from earlier passages but not from later passages. Mechanistically, we show that Thy1 expression decreases in FBs from later passages. Compared to Thy1 negative FBs, Thy1 positive FBs express higher IGFBP2, IGFBP7, and SPARC, which are important for angiogenesis and lumen formation during vasculogenesis in 3D. Moreover, Thy1 negative FBs physically block microvessel openings, reducing the perfusability of µVNs. Finally, by culturing immortalized FBs on gelatin-coated surfaces in serum-free medium, we are able to maintain the majority of Thy1 positive immortalized FBs to support perfusable µVN formation. Overall, we establish stable cell sources for µVN formation and characterize the functions of Thy1 positive and negative FBs in vasculogenesis in vitro.

Systems analysis of collaboration in 5 national tobacco control networks.

OBJECTIVES: We studied 5 members of the National Network Consortium on Tobacco Control in Priority Populations. These networks, which consist of governmental and nongovernmental organizations, targeted lesbian, gay, bisexual, and transgender persons; Asian Americans, Native Hawaiians, and Pacific Islanders; American Indians and Alaska Natives; African Americans; and persons with low socioeconomic status, respectively. METHODS: We used statistical network analysis modeling to examine collaboration among these national networks in 2007. RESULTS: Network size and composition varied, but all 5 networks had extensive interorganizational collaboration. Location and work area were significant predictors of collaboration among network members in all 5 networks. Organizations were more likely to collaborate with their network's lead agency; collaborations with other agencies were more likely if they were geographically close. Collaboration was perceived to be important for achieving the goals of the national network. CONCLUSIONS: The similarity of collaboration patterns across the 5 networks suggests common underlying partnership formation processes. Statistical network modeling promises to be a useful tool for understanding how public health systems such as networks and coalitions can be used to improve the nation's health.

Tobacco coverage in print media: the use of timing and themes by tobacco control supporters and opposition before a failed tobacco tax initiative.

OBJECTIVE: Tobacco control policies gained ground nationwide in 2006, with voters in nine states approving legislation to strengthen clean indoor air policies and increase tobacco excise taxes. Despite having the second lowest cigarette tax rate in the nation, Missouri was unsuccessful in passing its 2006 ballot initiative to raise the tax. An important way to encourage health-related policy change such as increasing tobacco taxes is through media coverage of tobacco issues. We examined how tobacco issues were presented in Missouri's print media leading up to the 2006 election. METHODS: This study analysed 1263 articles with tobacco content published in 187 Missouri newspapers in the year before the election. Articles were coded for general and tobacco-related characteristics including article type (news story, editorial, letter to the editor), tobacco control position (pro, neutral, anti) and article theme (economic, health, political). RESULTS: Most articles were news stories (73.6%) and pro-tobacco control (63.8%). The proportion of anti-tobacco control articles increased significantly (chi(2)=104.9, p<0.001) the month before the election, driven by an increase in economically themed articles. Economic articles were published more often in counties with less voter support for the tax (F=5.68, p<0.01). Finally, tobacco control position varied significantly across article types (chi(2)=148.3, p<0.01), with letters to the editor being anti-tobacco control most often. CONCLUSION: The media have a critical role in promoting public health goals and presenting health issues which influences formation of health policies. Tobacco control advocates must consider public opinion, opposition pressure, timing and themes in tobacco-related media coverage when promoting policy change.