Search

At higher order levels chromatin fibers in interphase nuclei are organized into loop domains. Gene regulatory elements (promoters and enhancers) are often located near the sites of loop attachments. Therefore, loop domains play a key role in regulation of cell transcriptional activity. We investigated the kinetics of DNA loop exit during single cell gel electrophoresis (the comet assay) of nucleoids obtained from two cell types that differ in their synthetic activity – human lymphocytes and lymphoblasts. Lymphocyte activation and transformation into lymphoblasts (blast transformation) was performed with interleukin 2. The results obtained suggest that a rearrangement of the loops occurs after lymphocyte activation. After blast transformation we observed an increase of the amount of loop domains on the surface of nucleoids against a decrease of the inner loop fraction. Therefore, the comet assay can be used for detection of large-scale changes in the cell nucleus that follow changes in cell functional state.

AIM: To evaluate the clinical and hematologic efficiency of splenectomy (SE) in patients with myelofibrosis (MF) resistant to conventional traditional treatment/MATERIAL AND METHODS: Case histories were retrospectively analyzed in 52 MF patients who had been followed up at the Hematology Research Center, Ministry of Health of the Russian Federation, in 2004 to 2012 and undergone therapeutic SE (47 patients with primary myelofibrosis, 4 with postpolycythemia myelofibrosis, and 1 with postthrombocythemia myelofibrosis). The mean age was 47 years at diagnosis and 53 years before surgery. The patients younger than 50 years of age constituted 60%. Massive and giant splenomegaly was detected in 37 (71%) patients. The spleen weighing 0.9 to 2.9 and 3 to 7 kg was removed in 15 (29%) and 35 (67%) patients, respectively. In 2 cases, the weight of the removed spleen was as much as 10 and 11 kg/RESULTS: By the moment of SE, the disease duration averaged 76 (from 1 to 240) months. Twenty-one (40%) patients developed perioperative complications, including bleeding (15%), thrombosis (11.5%), and infectious complications (13.5%). There were no deaths from surgical interventions in the intra- and early postoperative periods. In more than 80% of the patients after SE, their general condition improved and the symptoms of intoxication disappeared; in the majority of patients, the therapeutic effect lasted about 2 years. In the follow-up period, 33 (63%) patients died; the time to death averaged 27 (1-84) months following SE. The causes of death were blast transformation in 27 (82%) patients and comorbidity in 6 (18%); 19 (37%) patients with an average post-SE follow-up of 37 (4-72) months continued hydroxyurea treatment. The median survival after SE was equal to 3 years; the median overall survival was 11 years/CONCLUSION: SE is effective palliative care with an acceptable level of occurring complications for individual patients with MF. Contraindications to SE as blast crisis and severe comorbidities should be strictly taken into account.