Rat alveolar epithelial type II cells grown on polycarbonate filters form high-resistance monolayers and concurrently acquire many phenotypic properties of type I cells. Treatment with EGF has previously been shown to increase transepithelial resistance across alveolar epithelial cell (AEC) monolayers. We investigated changes in claudin expression in primary cultured AEC during transdifferentiation to the type I cell-like phenotype (days 0, 1, and 8), and on day 5 in culture +/- EGF (10 ng/ml) from day 0 or day 4. Claudins 4 and 7 were increased, whereas claudins 3 and 5 were decreased, on later compared with earlier days in culture. Exposure to EGF led to increases in claudins 4 and 7 and decreases in claudins 3 and 5. Claudin 1 was only faintly detectable in freshly isolated type II cells and remained unchanged over time in culture and after exposure to EGF. These results suggest that increases in transepithelial resistance accompanying AEC transdifferentiation and/or EGF exposure are mediated, at least in part, by changes in the pattern of expression of specific claudin isoforms.
Beta2-Adrenergic agonists stimulate alveolar epithelial sodium (Na(+)) transport and lung fluid clearance. Alveolar type II (AT2) cells have been reported to express beta2-adrenergic receptors (beta2AR). Given the large surface area covered by alveolar type I (AT1) cells and their potential role in alveolar fluid removal, we were interested in learning if AT1 cells express beta2AR as well. Because beta2AR is potentially susceptible to desensitization by G-protein-coupled receptor kinase 2 (GRK2), we also undertook localization of GRK2. beta2AR and GRK2 expression was evaluated in whole lung, isolated alveolar epithelial cells (AECs), and AECs in primary culture, and was localized to specific AEC phenotypes by immunofluorescence techniques. beta2AR is highly expressed in AT1 cells. beta2AR mRNA increases with time in culture as AT2 cells transdifferentiate towards the AT1 cell phenotype. Immunoreactive GRK2 is seen in both AT1 and AT2 cells in similar amounts. These data suggest that both AT1 and AT2 cells may contribute to the increased alveolar Na(+) and water clearance observed after exposure to beta2 adrenergic agents. Both cell types also express GRK2, suggesting that both may undergo desensitization of beta2AR with subsequent decline in the stimulatory effects of beta2-adrenergic agonists over time.
Although the harmful effects of smoking after a cancer diagnosis have been clearly demonstrated, many patients continue to smoke cigarettes during treatment and beyond. The NCCN Guidelines for Smoking Cessation emphasize the importance of smoking cessation in all patients with cancer and seek to establish evidence-based recommendations tailored to the unique needs and concerns of patients with cancer. The recommendations contained herein describe interventions for cessation of all combustible tobacco products (eg, cigarettes, cigars, hookah), including smokeless tobacco products. However, recommendations are based on studies of cigarette smoking. The NCCN Smoking Cessation Panel recommends that treatment plans for all patients with cancer who smoke include the following 3 tenets that should be done concurrently: (1) evidence-based motivational strategies and behavior therapy (counseling), which can be brief; (2) evidence-based pharmacotherapy; and (3) close follow-up with retreatment as needed.
Background Lung cancer screening (LCS) with low dose radiation computed tomography saves lives. Despite recent US Preventative Services Task Force draft endorsement of LCS, a minority of patients eligible is screened. Meaningful use is a set of standards for Electronic Health Records (EHR) established by the Centers for Medicare and Medicaid Services and includes reporting of smoking status. We sought to improve rates of LCS among patients treated at our institution by identifying eligible patients using augmented smoking-related meaningful use criteria. Methods We launched a LCS program at our institution, an NCCN cancer center, in January 2013. We developed a “Tobacco Screen”, administered by clinic staff to all adult outpatients every 6 months and entered into the EHR. This contained smoking-related meaningful use criteria, as well as a pack-year calculation and quit date, if applicable. Weekly electronic reports of patients who met eligibility criteria for LCS were generated, and EHR review excluded patients who had a chest CT within 12 months or who were undergoing cancer treatment. We then contacted those patients to review eligibility for LCS and communicated with the primary treating physician regarding the plan for LCS. Results During the first 3 months of the program, 4 patients were enrolled, 2 by physician-referral and 2 by self-referral. We then began to utilize the Tobacco Screen reports and identified 418 patients potentially eligible for LCS. Over the next 7 months, we enrolled a total of 110 patients. 58 (53%) were identified from the Tobacco Screen, 32 (29%) were self-referred, and 20 (18%) were physician referrals. Three stage I lung cancers were detected and treated. The tobacco screen was easily implemented by clinic staff and took a median time of 2 minutes to enter for current and former smokers. Lack of response to attempts at telephone contact and objection to paying out-of-pocket costs were the most common reasons for failing to screen eligible patients. Conclusions Use of augmented meaningful use criteria containing detailed tobacco exposure history is feasible and allows for identification of patients eligible for LCS in a medical center. Barriers to LCS include lack of insurance coverage and lack of systematic referral of patients at high risk.
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