علی اکبر شکارچی

According to the increasing evidence, abnormal expression of microRNAs is associated with tumorigenesis, tumor spread, and relapse in leukemias, including chronic myeloid leukemia (CML). The present study aimed to investigate the effect of miR-155 overexpression in K562 cells on cell cycle arrest and apoptosis induction.

The pLenti-III-pre miR-155-GFP vector was used to increase miR-155 expression in the K562 cell line through nucleofection compared to the pLenti-III-Backbone-GFP vector as a control group (Backbone). The flow cytometry method was employed to confirm the expression of the vector containing miR-155 in damaged cells. After transfection, the expression levels of miR-155, BAX, BCL2, CASP3, and TP53 were measured by the RT-qPCR method. The propidium iodide (PI) dye was used to study the cell cycle, and the stained cells were read by flow cytometry. The statistical significance was also defined as a P-value less than 0.05.

After confirming the increase in miR-155 expression when cells transfected with miR-155 were compared with cells transfected with Backbone, cell cycle arrest was observed in the miR-155 group. In the cells with increased expression of miR-155, the change in G0/S and G1/S ratios compared to Backbone was shown to be 7.5 and 4.5, respectively (P<0.05). Moreover, 48 hours after transfection and in the group expressing miR-155, the expression of TP53, BAX, and CASP3 genes increased, and the expression of BCL2 decreased (P<0.05).

The increase in the level of miR-155 caused cell cycle arrest and increased pro-apoptotic gene expression, which indicates that miR-155 inhibits tumor growth in CML.

  Resistance exercise is a method designed to increase muscle strength and endurance, leading to beneficial physiological changes in various tissues. The aim of this study is to investigate the pathological and structural effects of short-term and long-term resistance training on various tissues of male rats, including cardiac striatum, quadriceps, liver, kidney, and lung tissue.

 Forty male Wistar rats were randomly divided into four groups: one-month control, four-month control, one-month exercise, and four-month exercise. After the exercise period, the animals were anesthetized and dissected to separate various tissues, which were then treated with formalin and prepared for analysis.

  The study findings showed that liver tissue did not show significant histopathological changes in response to exercise. However, in the heart tissue, mild hyperemia and hypertrophy of muscle cells were observed in the exercise groups compared to the control groups. In the quadriceps muscle, hypertrophy was observed to a lesser extent in the one-month exercise group and to a greater extent in the four-month exercise group. There was a significant difference in the diameter of the muscle cells of the quadriceps muscle between the one-month and four-month exercise groups, indicating the beneficial effects of long-term exercise. Additionally, an increase in the size of the epithelial tissue of the urinary tubes was observed in both exercise groups, which indicates an increase in kidney function due to exercise.

 Overall, the results of this study show that resistance exercise can lead to beneficial physiological changes in various tissues, especially with long-term exercise. Understanding these changes can increase our knowledge about the benefits of exercise.

Practical Implications:

Resistance exercises, through actions such as hyperemia, hypertrophy of muscle cells, and hypertrophy of the epithelial tissue of urinary tubes, improve the efficiency of the heart, kidneys and muscles during sports exercises, especially with long-term exercise.

Health promotion lifestyle includes actions and beliefs that persuade people to stay healthy and protect them against disease. This study was conducted to investigate some aspects of lifestyle of rural primary health-care workers (Behvarzes) in Khalkhal and Kosar counties. In this cross-sectional study, 120 Behvarzes were recruited in Khalkhal and Kosar counties. Data were gathered using a questionnaire consisting demographic information and walker Health Promotion Life Style (HPLP) Questionnaires. Statistical tests including the descriptive statistics, independent t-test, ANOVA and Welch's strong test followed by Tukey's post hoc test were performed using SPSS (v.20). The Mean age of participants were 40±4.6 years and the majority of them were female (66%). The overall score of HPLP was 2.3±0.62, and the highest and lowest scores were observed in “Spiritual Growth” and “Interpersonal Relations” dimensions, respectively. There was a significant statistical relationship between different dimensions of lifestyle and demographic variables including "physical activity" and age; "interpersonal support" and gender and marital status and "self-actualization" and gender and finally, overall score of lifestyle and work experience respectively. Based on the results of the present study, health promotion behaviors in Behvarzes (rural health care providers), were not favorable in comparison with similar studies. Different dimensions of participants' lifestyle showed a significant relationship with some of the demographic variables including age, gender and marital status. In both sexes, the lowest score was seen in the "Interpersonal Relations" dimension.