Efficacy of Chemotherapy in Acute Leukemia Patients Resistant to Previous Standard Treatment According to the Series Measurement of WT1 Gene Expression

Aim. To estimate the efficacy of chemotherapy in acute leukemia patients resistant to previous standard treatment according to the series measurement of WT1 expression. Materials & Methods. The series measurement of WT1 expression formed the basis of the efficacy estimation of induction chemotherapy in 31 patients (15 men and 16 women aged from 3 months to 68 years; the median age was 28 years) with prognostically unfavourable variants of acute myeloid (AML) and lymphoblastic leukemia (ALL) (23 AML and 8 ALL patients). The WT1 gene expression was measured at baseline and 2–3 weeks after the treatment by the quantitative real-time PCR. The threshold level for detection was 250 copies of WT1/104 copies of ABL. The cytogenetic profile of leukemia cells was assessed by standard cytogenetics and FISH. Results. The baseline expression level of WT1 varied from 305 to 58,569 copies/104 copies of ABL. The expected reduction of WT1 expression after the first induction chemotherapy treatment was reported in 22/23 (96 %) AML patients and in 6/8 (75 %) ALL patients. According to our results WT1 expression reached the threshold in 13/31 (42 %) patients, including 9 AML patients and 4 ALL patients. After 11/31 (35 %) patients received the second course of treatment, WT1 expression level became normal in 8 cases (5 ALL and 3 AML patients). Despite high dose chemotherapy, HSCT and such agents as blinatumomab and gemtuzumab, an unfavourable outcome was observed in 18/31 (58 %) patients including 6 patients with complex karyotype (CK+) and 2 patients with monosomal karyotype (MK+). Once the MK+ and CK+ combination was observed, in another case the MK+ was combined with the prognostically unfavourable inv(3)(q21q26) inversion. Conclusion. Our results show that the molecular monitoring should be included as part of treatment of the prognostically unfavourable acute leukemia. The WT1 gene was shown to be the most appropriate marker. WT1 expression was shown to correlate with the common fusion genes allowing to estimate the blast cell count at the molecular level

Object recognition is enabled by an experience-dependent appraisal of visual features in the brain’s value system

This paper addresses perceptual synthesis by comparing responses evoked by visual stimuli before and after they are recognized, depending on prior exposure. Using magnetoencephalography, we analyzed distributed patterns of neuronal activity – evoked by Mooney figures – before and after they were recognized as meaningful objects. Recognition induced changes were first seen at 100–120 ​ms, for both faces and tools. These early effects – in right inferior and middle occipital regions – were characterized by an increase in power in the absence of any changes in spatial patterns of activity. Within a later 210–230 ​ms window, a quite different type of recognition effect appeared. Regions of the brain’s value system (insula, entorhinal cortex and cingulate of the right hemisphere for faces and right orbitofrontal cortex for tools) evinced a reorganization of their neuronal activity without an overall power increase in the region. Finally, we found that during the perception of disambiguated face stimuli, a face-specific response in the right fusiform gyrus emerged at 240–290 ​ms, with a much greater latency than the well-known N170m component, and, crucially, followed the recognition effect in the value system regions. These results can clarify one of the most intriguing issues of perceptual synthesis, namely, how a limited set of high-level predictions, which is required to reduce the uncertainty when resolving the ill-posed inverse problem of perception, can be available before category-specific processing in visual cortex. We suggest that a subset of local spatial features serves as partial cues for a fast re-activation of object-specific appraisal by the value system. The ensuing top-down feedback from value system to visual cortex, in particular, the fusiform gyrus enables high levels of processing to form category-specific predictions. This descending influence of the value system was more prominent for faces than for tools, the fact that reflects different dependence of these categories on value-related information

New Сytogenetic Approaches in Patients with Primary Myelofibrosis

Aim. To evaluate the potential of a new cytogenetic technique in patients with primary myelofibrosis (PMF). Materials and methods. 48-hour blood cell cultures (according to Singh et al., 2013) were used for cytogenetic study in 11 PMF patients (5 female, 6 men, aged 32–60 years; median 48.6 years). GTG-banding and different types of fluorescence in situ hybridization (FISH) techniques were used for identification of chromosomal aberrations. Results. The incidence of abnormal karyotypes in blood cultures was significantly higher than that in standard bone marrow cultures (82 vs 27 %; p < 0.01). The polyploid clones were found in blood cultures of 45 % of patients. Structural chromosomal aberrations were found in chromosomes 6, 1, 3, as well as 16 and 17 (in 2 and 1 patients with each aberration, respectively). In all but one patients these abnormalities in diploid and polyploid metaphases were identical. Partial 1q trisomy resulted from adding of additional (1q21–1q44) material translocated to the short arm of chromosome 5 to the material of 2 normal homologue of chromosome 1. It seems that 1q+, i(17q) and some others chromosomal abnormalities were secondary, whereas 6p21 locus involvement may be a primary defect in PMF. The t(3;6)(q25;p21) translocation described for the first time and confirmed by FISH should be considered a variant of well-known translocation t(1;6). Allo-HSCT in 2 patients with 1q+ was successful, whereas there were problems with engraftment in a female patient with prognostically unfavorable t(3;3)(q21;q26) translocation associated with the EVI1 gene overexpression. Conclusion. Cytogenetic examinations in blood cultures provide important additional information about PMF patients