Prevalence of asthma symptoms in Golestan schoolchildren aged 6–7 and 13–14 years in Northeast Iran

Asthma is the most common chronic disease among children, and its incidences are often imminent among elementary schoolchildren. This study aimed to examine the prevalence of asthma symptoms in Golestan schoolchildren aged 6–7 and 13–14 years in Northeast Iran. The prevalence rate was compared according to age group (aged 6–7 years vs. aged 13–14 years) and gender (male vs. female). In this cross-sectional study, 1706 Iranian schoolchildren aged 6–7 and 13–14 years in Golestan Province were enrolled. Participants completed questionnaires between February and July 2014. Asthma symptoms were assessed using the questionnaire of the International Study of Asthma and Allergies in Childhood protocol in Persian. The logistic regression model was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of the asthma symptoms for each of the gender and age groups. The prevalence rates of “current asthma” symptoms and “asthma ever” in all the children were estimated as 9.5% and 7.5%, respectively. The prevalence of asthma (“asthma ever” and “wheezing in the past 12 months”) in junior high schoolchildren (aged 13–14 years) is higher than that in elementary schoolchildren (aged 6–7 years) (P < 0.05). The prevalence of the severity of wheezing in girls is lower than that in boys (OR = 1.7, 95%CI = 1.06–2.96, P = 0.02). Asthma is still a major public health problem. This study shows that the prevalence of the asthma symptoms in boys is lower than that in girls in both age groups, and the severity of asthma in girls is higher than that in boys aged 13–14 years. © 2016 Higher Education Press and Springer-Verlag Berlin Heidelber

Epidemiology of tuberculosis in northeast of Iran: A population-based study

Background: Tuberculosis (TB) is currently one of the greatest problems in public health. Mycobacterium tuberculosis infects about one third of the world's population, of whom more than 80% are living in developing countries. The incidence and prevalence of TB are very different in various parts of Iran and also throughout the world. Golestan province is one of the areas in the country where the risk of TB is the highest because of its ethnically varied population and special location. We aimed to describe the prevalence of TB and related demographic data in Golestan province (northeast of Iran). Methods: We collected all data of patients with TB who registered in 2005 and 2006 in each of the 11 districts of Golestan province. Data were entered into the computer database and age-specific incidence rates per 100 000 population were calculated. Results: There were 321 new smear-positive cases. The incidence and prevalence of TB were 20.88 and 38.15 per 100 000 population, respectively. The male to female ratio was 0.96. Relapse of TB was reported in 20 patients. We found 141 cases of extrapulmonary TB, with a significant predominance in women. The organ most frequently involved in extrapulmonary TB was the lymph nodes. Generally, smear-negative TB was more common in men and extrapulmonary TB was more common in women. Conclusion: The incidence and prevalence of TB were higher in Golestan province in comparison with other provinces in Iran. We suggest using improved screening strategies and better education about TB for high-risk groups and physicians

Stochastic model for nucleosome sliding in the presence of DNA ligands

Heat-induced mobility of nucleosomes along DNA is an experimentally well-studied phenomenon. A recent experiment shows that the repositioning is modified in the presence of minor-groove binding DNA ligands. We present here a stochastic three-state model for the diffusion of a nucleosome along DNA in the presence of such ligands. It allows us to describe the dynamics and the steady state of such a motion analytically. The analytical results are in excellent agreement with numerical simulations of this stochastic process.With this model, we study the response of a nucleosome to an external force and how it is affected by the presence of ligands.Comment: 10 pages, 8 figures, submitted to Eur. Phys. J.

Effect of Bending Anisotropy on the 3D Conformation of Short DNA Loops

The equilibrium three dimensional shape of relatively short loops of DNA is studied using an elastic model that takes into account anisotropy in bending rigidities. Using a reasonable estimate for the anisotropy, it is found that cyclized DNA with lengths that are not integer multiples of the pitch take on nontrivial shapes that involve bending out of planes and formation of kinks. The effect of sequence inhomogeneity on the shape of DNA is addressed, and shown to enhance the geometrical features. These findings could shed some light on the role of DNA conformation in protein--DNA interactions

Nonlinear Mechanical Response of DNA due to Anisotropic Bending Elasticity

The response of a short DNA segment to bending is studied, taking into account the anisotropy in the bending rigidities caused by the double-helical structure. It is shown that the anisotropy introduces an effective nonlinear twist-bend coupling that can lead to the formation of kinks and modulations in the curvature and/or in the twist, depending on the values of the elastic constants and the imposed deflection angle. The typical wavelength for the modulations, or the distance between the neighboring kinks is found to be set by half of the DNA pitch.Comment: 4 pages, 3 encapsulated EPS figure

Hydrogel nanoparticle encapsulated plasmid as a suitable gene delivery system

To facilitate the delivery of genetic material, the use of appropriate carriers such as polymers is necessary. Nanoparticles comprising of chitosan-alginate polymers were formed through pregel preparation method. Chi/Alg nanoparticles had a mean Z-Average diameter of 161.8 nm and mean zeta 29.3 mV, respectively. The ability of plasmid-complex in preventing DNA migration showed Chi/Alg nanoparticles have great capacity to maintain plasmid. The efficiency of nanoparticles for transfection of pEGFP-N1 plasmid in the cultured HEK 293 cells was measured by flow cytometry. Cell viability assays indicated that nanoparticles had no toxic effect on HEK 293 cells after 4 or 24 h. Our suitable candidate for gene delivery would be alg/chi nanoparticles.Для облегчения доставки генетического материала необходимо использование подходящих носителей, таких как полимеры. Наночастицы, состоящие из хитозан-альгинатных полимеров, были получены методом подготовки прегеля. Chi/Alg наночастицы имели средний диаметр 161.8 нм (Z-Average) и средний zeta-потенциал 29.3 mV. Отсутствие миграции ДНК во время электрофореза комплексов плазмиды с наночастицами показало, что Chi/Alg наночастицы могут удерживать плазмидную ДНК внутри комплекса. Эффективность наночастиц для трансфекции плазмиды pEGFP-N1 в культивируемые клетки HEK 293 была измерена с помощью жидкостной цитометрии. Тесты на жизнеспособ-ность клеток показали, что наночастицы не имели токсичного эффекта на клетки HEK 293 через 4 ч или 24 ч. Наночастицы Alg/Chi являются подходящим кандидатом для доставки генов