Viscoelastic Properties of Human Tracheal Tissues.

The physiological performance of trachea is highly dependent on its mechanical behavior, and therefore, the mechanical properties of its components. Mechanical characterization of trachea is key to succeed in new treatments such as tissue engineering, which requires the utilization of scaffolds which are mechanically compatible with the native human trachea. In this study, after isolating human trachea samples from brain-dead cases and proper storage, we assessed the viscoelastic properties of tracheal cartilage, smooth muscle, and connective tissue based on stress relaxation tests (at 5% and 10% strains for cartilage and 20%, 30%, and 40% for smooth muscle and connective tissue). After investigation of viscoelastic linearity, constitutive models including Prony series for linear viscoelasticity and quasi-linear viscoelastic, modified superposition, and Schapery models for nonlinear viscoelasticity were fitted to the experimental data to find the best model for each tissue. We also investigated the effect of age on the viscoelastic behavior of tracheal tissues. Based on the results, all three tissues exhibited a (nonsignificant) decrease in relaxation rate with increasing the strain, indicating viscoelastic nonlinearity which was most evident for cartilage and with the least effect for connective tissue. The three-term Prony model was selected for describing the linear viscoelasticity. Among different models, the modified superposition model was best able to capture the relaxation behavior of the three tracheal components. We observed a general (but not significant) stiffening of tracheal cartilage and connective tissue with aging. No change in the stress relaxation percentage with aging was observed. The results of this study may be useful in the design and fabrication of tracheal tissue engineering scaffolds.

Third study on WHO MPOWER Tobacco Control Scores in Eastern Mediterranean countries 2011-2015.

This study was conducted to quantify the implementation of the MPOWER policies and to assess any possible changes across Eastern Mediterranean Region (EMR) countries. In this comparative cross-sectional study based on 10 categories mentioned in MPOWER report 2015 a checklist was designed. Seven questions were scored from 0-4 and three from 0-3. The 22 EMR countries were ranked and compared by their total score on a scale of 0-37. The highest scores were achieved by Egypt and the Islamic Republic of Iran. Pakistan, Sudan and Yemen showed progress, while Bahrain, Jordan, Kuwait, Oman, and the Syrian Arab Republic had decreased scores. The total score of the EMR countries had decreased compared to 2013. Thus, there remains a need for greater focus on tobacco taxation and smoke-free policies to address this retrograde step.

Time trend of smoking scenes in Iranian movies during the past three decades (1982-2011): a historical analysis.

BACKGROUND: Evidence from the USA and elsewhere has linked smoking depictions in movies with youth smoking initiation. Prior research has not focused on depictions in films produced in the Middle East, however. OBJECTIVE: We reviewed the 10 most commercially successful Iranian films released each year over three decades (1982-2011) to determine trends in depictions of tobacco use over time. METHODS: Each movie was reviewed in its entirety, and depictions of smoking were recorded and classified as direct (characters holding or using tobacco products) and indirect (tobacco products appearing in the frame, but not being used). Time trends in average duration of direct, indirect and total smoking depictions were analysed using linear regression and Cohen's κ coefficient. RESULTS: The mean duration of tobacco depictions in the most commercially successful Iranian films fluctuated yearly over the 3 decades, but with an overall significant upward trend (p<0.005). The proportion of movies depicting tobacco consumption during the three decades was 36% (1982-1991), 60% (1992-2001) and 74% (2002-2011), respectively. The average proportion of total movie time for these depictions (0.75%, 1.41%, 2.08%) increased significantly (p<0.005) over the 3 decades as did the average duration of smoking depictions,(39.1, 67 and 99.3 s, respectively, p<0.005). CONCLUSIONS: The significant increase in the proportion of movies depicting tobacco consumption and in the duration of smoking depictions over the past 30 years underscores the need for increased regulation of the Iranian film industry to minimise this important source of influence on tobacco initiation in young people.

Expression of miRNAs in non-small-cell lung carcinomas and their association with clinicopathological features.

Lung cancer is recognized as a leading cause of cancer-related deaths worldwide. Over the past several years, evidence emerged that microRNAs (miRNAs), a class of small non-coding RNA molecules regulating gene expression at posttranscriptional level, play an important role in cell functioning, as well as in human diseases. Here, we analyzed expression of miR-15a/16, miR-21, miR-34a, miR-126, miR-128, and miR-210 at transcriptional level in 30 non-small-cell lung carcinoma (NSCLC) tumor tissues compared to the matched adjacent normal tissues and their correlation with clinicopathological features of the patients. Samples were collected from the NSCLC patients undergoing surgery before radiotherapeutic or chemotherapeutic treatment. Expression levels of miRNAs were assessed by TaqMan RT-PCR assay. The data obtained in this study were processed using REST 2009 and SPSS statistical software. The graphs were designed by GraphPad prism 5.0. In tumor samples, we found downregulation of miR-15a/16 (50/83.3%), miR-34a (83.3%), miR-126 (70%), and miR-128 (63.3%). At the same time, miR-21 and miR-210 were upregulated by 53.3 and 66.6% in cancer tissue versus matched adjacent normal tissues, respectively. No significant correlation was found between the expression levels of miR-15a/16, miR-21, miR-34a, miR-126, miR-128, and miR-210 and lymph node, tumor size, sex, and smoking. However, the study demonstrated a correlation between a change in expression of miR-15, miR-16, miR-34a, miR-126, and miR-210 compared to normal tissues and TNM staging (P < 0.05). Furthermore, miR-126 expression level was different in adenocarcinomas and squamous cell carcinoma (SCC) subtype (P < 0.1). Detailed analysis revealed significant change in expression of miR-15a/16, miR-34a, miR-126, and miR-210 in NSCLC tumor samples indicating involvement of these miRNAs in lung cancer pathogenesis. miR-210 demonstrated the most consistent increase in tumor tissues between different patients, suggesting its potential significance for NSCLC.

Mechanical Characterization and Constitutive Modeling of Human Trachea: Age and Gender Dependency.

Tracheal disorders can usually reduce the free lumen diameter or wall stiffness, and hence limit airflow. Trachea tissue engineering seems a promising treatment for such disorders. The required mechanical compatibility of the prepared scaffold with native trachea necessitates investigation of the mechanical behavior of the human trachea. This study aimed at mechanical characterization of human tracheas and comparing the results based on age and gender. After isolating 30 human tracheas, samples of tracheal cartilage, smooth muscle, and connective tissue were subjected to uniaxial tension to obtain force-displacement curves and calculate stress-stretch data. Among several models, the Yeoh and Mooney-Rivlin hyperelastic functions were best able to describe hyperelastic behavior of all three tracheal components. The mean value of the elastic modulus of human tracheal cartilage was calculated to be 16.92 ± 8.76 MPa. An overall tracheal stiffening with age was observed, with the most considerable difference in the case of cartilage. Consistently, we noticed some histological alterations in cartilage and connective tissue with aging, which may play a role in age-related tracheal stiffening. No considerable effect of gender on the mechanical behavior of tracheal components was observed. The results of this study can be applied in the design and fabrication of trachea tissue engineering scaffolds.

Analysis of arterial wall remodeling in hypertension based on lamellar modeling.

Arterial wall remodels its geometry and mechanical properties in response to hypertension to maintain functionality. The elevated pressure is sensed through cellular mechanotransduction pathways, and extra extracellular matrix is synthesized, leading to thickening and stiffening. The present study enquires the response of aortic lamellar structure to hypertensive blood pressure regarding unchanged circumferential stress "profile" across the media as remodeling criterion. We tested the hypothesis that alterations in the thickness of structural layers contributes to maintain stress profile with least deviation from normotensive conditions. To test this notion, finite element analysis was recruited to evaluate stress profile, considering wall residual stress, and lamellar structure was adjusted through an optimization algorithm. Our results indicated 47% increased thickness of the aortic media that originates from nonhomogenous thickening of the microstructural units. The thickening and stiffening responses of the wall tissue were coupled, and the optimized pattern of hypertension-induced remodeling was established.

Evaluation of Biaxial Mechanical Properties of Aortic Media Based on the Lamellar Microstructure.

Evaluation of the mechanical properties of arterial wall components is necessary for establishing a precise mechanical model applicable in various physiological and pathological conditions, such as remodeling. In this contribution, a new approach for the evaluation of the mechanical properties of aortic media accounting for the lamellar structure is proposed. We assumed aortic media to be composed of two sets of concentric layers, namely sheets of elastin (Layer I) and interstitial layers composed of mostly collagen bundles, fine elastic fibers and smooth muscle cells (Layer II). Biaxial mechanical tests were carried out on human thoracic aortic samples, and histological staining was performed to distinguish wall lamellae for determining the dimensions of the layers. A neo-Hookean strain energy function (SEF) for Layer I and a four-parameter exponential SEF for Layer II were allocated. Nonlinear regression was used to find the material parameters of the proposed microstructural model based on experimental data. The non-linear behavior of media layers confirmed the higher contribution of elastic tissue in lower strains and the gradual engagement of collagen fibers. The resulting model determines the nonlinear anisotropic behavior of aortic media through the lamellar microstructure and can be assistive in the study of wall remodeling due to alterations in lamellar structure during pathological conditions and aging.

Assessment of Different Quit Smoking Methods Selected by Patients in Tobacco Cessation Centers in Iran.

BACKGROUND: Health systems play key roles in identifying tobacco users and providing evidence-based care to help them quit. This treatment includes different methods such as simple medical consultation, medication, and telephone counseling. To assess different quit smoking methods selected by patients in tobacco cessation centers in Iran in order to identify those that are most appropriate for the country health system. METHODS: In this cross-sectional and descriptive study, a random sample of all quit centers at the country level was used to obtain a representative sample. Patients completed the self-administered questionnaire which contained 10 questions regarding the quality, cost, effect, side effects and the results of quitting methods using a 5-point Likert-type scale. Percentages, frequencies, mean, T-test, and variance analyses were computed for all study variables. RESULTS: A total of 1063 smokers returned completed survey questionnaires. The most frequently used methods were Nicotine Replacement Therapy (NRT) and combination therapy (NRT and Counseling) with 228 and 163 individuals reporting these respectively. The least used methods were hypnotism (n = 8) and the quit and win (n = 17). The methods which gained the maximum scores were respectively the combined method, personal and Champix with means of 21.4, 20.4 and 18.4. The minimum scores were for e-cigarettes, hypnotism and education with means of 12.8, 11 and 10.8, respectively. There were significant differences in mean scores based on different cities and different methods. CONCLUSIONS: According to smokers' selection the combined therapy, personal methods and Champix are the most effective methods for quit smoking and these methods could be much more considered in the country health system.

Key Policy Makers' Awareness of Tobacco Taxation Effectiveness through a Sensitization Program.

The implementation of 5 of the 6 WHO MPOWER program in Iran is satisfactory; the only notable shortcoming is the lack of tobacco taxation increases. This study was designed to increase key policy makers' awareness of tobacco taxation effectiveness through a sensitization program in Iran. This analytical and semi-experimental study in 2014 included 110 tobacco control key policy makers, who were trained and received educational materials on the importance of tobacco taxation. A valid and reliable questionnaire was completed before and three months after intervention. Data were analyzed using mean (SD), t-Test and analysis of variance. The mean (SD) scores at pre- and post-test were 2.7 ± 3 and 8.8 ± 1 out of 10, respectively. Paired t-tests demonstrated a significant difference in the pre- post-test knowledge scores. Increasing knowledge and promoting favorable attitudes of policy makers can lead to greater attention which could in turn change tobacco taxation policies.

Quit Smoking Experts' Opinions toward Quality and Results of Quit Smoking Methods Provided in Tobacco Cessation Services Centers in Iran.

BACKGROUND: One of the core responsibilities of health system is to treat tobacco dependence. This treatment includes different methods such as simple medical consultation, medication, and telephone counseling. To assess physicians' opinions towards quality and result of different quit smoking methods provided in tobacco cessation services centers in Iran. METHODS: In this cross-sectional and descriptive study, random sampling of all quit centers at country level was used to obtain a representative sample size of 100 physicians. Physicians completed a self-administered questionnaire which contained 10 questions regarding the quality, cost, effect, side effects, and the results of quitting methods using a 5-point Likert-type scale. Percentages, frequencies, mean, T-test, and variance analyses were computed for all study variables. RESULTS: Most experts preferred to use combination quit smoking methods and then Nicotine Replacement Therapy (NRT) with 26 and 23, respectively. The least used methods were quit line and some methods without medication with 3 cases. The method which gained the maximum scores were telephone consultation, acupuncture, Willpower, Champix, combined method, and Interactive Voice Response (IVR) with the mean of 23.3, 23, 22.5, 22, 21.7 and 21.3, respectively. The minimum scores were related to e-cigarette, some methods without medication, and non-NRT medication with the mean of 12.3, 15.8 and 16.2, respectively. There were no significant differences in the mean of scores based on different cities (P = 0.256). Analysis of variance in mean scores showed significant differences in the means scores of different methods (P < 0.000). CONCLUSIONS: According to physicians acupuncture, personal methods and Champix are the most effective methods and these methods could be much more feasible and cost effective than other methods.

The second study on WHO MPOWER tobacco control scores in Eastern Mediterranean Countries based on the 2013 report: improvements over two years.

BACKGROND: Following MPOWER's 2011 report, a study was conducted to quantify the implementation of MPOWER tobacco control policies in the Eastern Mediterranean Region (EMR) in 2013 to assess any possible change during the last two years.  METHODS: In this cross sectional study, based on 10 categories mentioned in MPOWER 2013, a checklist was designed and its scoring was agreed upon by Iranian and international tobacco control specialists. Seven questions were scored from 0 - 4 and 3 from 0 - 3. The 22 countries were ranked by their total score on a scale of 0 to 37.  RESULTS: Among the 22 countries in the EMR, Iran, Kuwait, Egypt, Lebanon, Gaza and West bank and Jordan were scored 31, 28, 28, 26, 25 and 25 respectively. 14 countries scored more than 50%, a small improvement; 5 countries have seen their scores fall, and three countries received the same score as last time. The highest overall improvement was attributed to the warning label, and the sharpest decline was observed in the consumption category. CONCLUSION: There has been a slight overall improvement in tobacco control planning, although the desired levels have yet to be reached and some countries in the region have fared worse.