M Mahmoodi, Ar Khooi, M Farzadnia, M Rastin,
Volume 15, Issue 1 (4-2007)
Abstract
Introduction: HTLV-1 , the first known human retrovirus belongs to oncovirus subfamily of retroviruses. The major characteristic of HTLV-1 is its highly restricted geographic prevalence. Northern part of Khorasan is an endemic region of HTLV-1 infection. Epidemiological studies can help in designing preventive programs for HTLV-1 infection. The aim of this study was the establishment of a PCR technique for determination of HTLV-1 infection in paraffin-embedded tissues.
Methods: In this experimental laboratory study for establishment of a technique, PCR was initially optimized using Beta-actin primers on various formalin fixed paraffin-embedded tissues from liver, spleen, skin and lymph nodes. The optimized concentration of Mgcl2 was 2mm, primer was 8 pmol. Optimized concentration of DNA was different according to the kind of tissue. HTLV-1 infection was determined by applying tax, pol, env and LTR primers on 50 paraffin-embedded lymph node tissues . The reporoducibility of this technique was shown for skin and lymph node tissues infected with HTLV-1.
Resuls: In 50 lymph node tissues, one case with pathologic diagnosis of NHL was positive with all 5 sets of primers (tax, Pol, env and LTR primers) and the other case was positive with only two sets of tax primers but was negative with pol, env and LTR primers. The prevalence of infection was 2% among lymph node specimens. (1 of 50 specimens ) and if the second case is considered, the prevalence would be 4%.
Conclusion: Comparison of the results of this study with another study on blood specimens (seroprevalence2.3%) was not statistically significant thus confirming the results of one another. (P=0.883)
A Oveisi, M Mortazavizadeh, M Arjmand, H Fazli, Mh Sheikhha,
Volume 17, Issue 3 (7-2009)
Abstract
Introduction: DNA extraction methods are very important for genetics research and diagnostic tests. In These methods are also important for detecting genetic diseases or in cancers for investigating genetic changes during cancer progression or treatment. Therefore, selection of the best method for DNA extraction from different samples such as bone marrow (BM) or peripheral blood (PB) and their slides is very important.
Methods: In the present research, DNA was extracted from 5 different samples including 1-PB, 2-BM slides stained by Gimsa method, 3-Gimsa stained PB slides from archives, 4-new Gimsa stained PB slides and 5-non stained new PB slides by 3 different methods salting-out, boiling and phonal chloroform method. In all of the groups, three DNA parameters were investigated 1-OD (Optimal Density), 2-DNA concentration and 3-Outcome (PCR results).
Results: The best DNA quality was achieved by salting-out method (OD=1.74), while the worst quality was by the boiling method (OD<1.0). The DNA quality of all the samples was similar in the salting-out and phenol chloroform methods. Regarding DNA quantity, the best result was from boiling method (6.7µg / ml). The least amount of DNA was obtained by the phenol chloroform method and salting-out method also resulted in the least quantity of extracted DNA. Regarding the outcome of DNA extraction or the PCR results, all the three methods showed 100% positive results for peripheral blood samples, while boiling method had the best outcome for BM slides, archive stained PB slides, new stained PB slides and non-stained PB slides (100%, 88%, 84% and 72% respectively).
Discussion: The present research indicated that except non stained PB slides, the DNA extraction from all other samples showed very good results. In addition, the research showed that there is no difference in DNA extraction of new or archive slides.
