مجله پیاورد سلامت
سال چهارم شماره 3 (پاییز 1389)

MicroRNAs (miRNA) are small noncoding RNA molecules that transcribed by RNA polymerase II. After biogenesis, these molecules act by incorporation into the RNA-induced silencing complex (RISC). MiRNAs are involved in multiple physiological and pathological processes such as proliferation, differentiation, apoptosis and cancer. Recently several studies reported down regulation of mir-150 during erythropoesis. Since hemoglobin expression is valuable indicator of erythroid differentiation we evaluated the mir-150 downregulation effect on alpha chain expression by Quantitative RT-PCR.

K562cells were grown in RPMI1640 in standard condition. K562 cells were transfected by microRNA 150 Inhibitor using transfection kit. Mir-150 downregulation was confirmed by miRNA Real time PCR, followed by Q-RT-PCR to investigate the alpha chain expression changes.

By relative QRT-PCR the alpha chain expression was increased 10 folds in comparison to untransfected and scramble cells. Furthermore, the differences were statistically significant (P<0.05)Discussion and

Elevation of alpha chain expression in our study showed that mir-150 downregulation has a crucial role in erythroid differentiation and can introduce as a novel marker in alpha thalassemia. Further researches to find out the detail mechanism and miRNAs genes target could improve our knowledge about miRNAs potential in management of diseases and their applications in gene therapy and regenerative medicine.

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia. APL is characterized by a balanced reciprocal translocation between chromosomes 15 and 17, t(5;17)). Important therapeutic strategies for this disease are ATRA and Arsenic trioxide. To eliminate tumor cells with arsenic, high dose of arsenic is needed. But high dose is toxic for normal tissue. The purpose of this study is Assessment of effect of low dose of arsenic trioxide in combination with AZT on NB4 cell line (APL cell line) to reduce toxic effect of high dose arsenic.

In this study after NB4 cell line culture and proliferation, the cells treated with low dose of arsenic trioxide(0.5µM) in combination with different doses of AZT(50, 100, 200 µM) and then viability and metabolic activity was assessed by try pan blue and MTT assay respectively.

Low dose of arsenic (0.5µm) alone and in combination with dose of 50µm of AZT has little effect on viability and metabolic activity but in combination with higher dose of AZT has significant effect on viability and metabolic activity and both viability and metabolic activity significantly reduced.Discussion and

Different apoptosis- induced mechanisms cause apoptosis by arsenic and AZT. Since some of these mechanisms between AZT and arsenic are similar, so maybe these similar mechanisms cause synergic effect and significant reduction of viability and metabolic activity in combination of these two drugs.

Using Hirsch index as an important tool to describe the scientific outputs of researchers has caused some authors to increase their self-imposed parameters, increase, citing themselves. Therefore it is necessary to consider the effect of self-citation on Hirsch index for every author to have better measuring on the quality of researchers scientific production.

This research is descriptive method of citation analysis in general and specifically self-citation analysis. The study, are Iranian prolific authors in the field of medicine that have at least 30 documents indexed in Web of Science database between 2004 to 2006. Citations following up was studied till December 2010.Results was analysis using Excel software version 2007.

The average self-citation observed between prolific authors in medical field was 25/89 percent. Hirsch index for 30/77 percent of authors had changed considerably. The authors rating scheme based on Hirsch index was done after removing self - citation so that 38/46 percent of authors decreased to lower level.Discussion and

Considering that 10 to 30 percent of self-citation can be normal and justified, the status of self-citatin of Iranian prolific authors in medical field is desirable. Also, lower rates of self - citation of these authors doesnot affect Hirsch index.