Immunocytochemical markers in acute leukaemias diagnosis

The study included 1742 patients with acute myeloblastic leukaemias (AML) and acute lymphoblastic leukaemias (ALL), Kyiv city residents and patients from 20 regions of Ukraine. Bone marrow and blood smears were sent at diagnosis to Reference Center. The analysis was based on May-Grünvald-Giemza (MGG) stain and cytochemical reactions (MPO, acNSE, CAE, AP, PAS). Immunocytochemical techniques (APAAP, LSAB) and broad panel of monoclonal antibodies (MoAbs) against lineage specific and differentiation antigens of leukocytes were employed for immunophenotyping of leukemic blast cells directly in blood and bone marrow smears. Different types of AML were defined by the expression of the cell surface and cytoplasmic antigens. Immunocytochemical study was required especially in diagnosing of AML with minimal differentiation, acute megakaryoblastic leukaemia, acute erythroid leukaemia and acute leukaemias of ambiguous lineage. Acute lymphoblastic leukaemias was broadly classified into B-lineage and T-lineage ALL. According to the degree of B-lymphoid differentiation of the blast cells four subtypes of B-lineage ALL were established. T-lineage ALL observed in patients were also divided into four subtypes. Immunocytochemical examination was required to diagnose AL of ambiguous lineage with no clear evidence of lineage differentiation (acute undifferentiated leukaemia) or those with blasts that express markers of more than one lineage (mixed phenotype acute leukaemias)

Numerical simulations of shocks encountering clumpy regions

We present numerical simulations of the adiabatic interaction of a shock with a clumpy region containing many individual clouds. Our work incorporates a sub-grid turbulence model which for the first time makes this investigation feasible. We vary the Mach number of the shock, the density contrast of the clouds, and the ratio of total cloud mass to inter-cloud mass within the clumpy region. Cloud material becomes incorporated into the flow. This "mass-loading" reduces the Mach number of the shock, and leads to the formation of a dense shell. In cases in which the mass-loading is sufficient the flow slows enough that the shock degenerates into a wave. The interaction evolves through up to four stages: initially the shock decelerates; then its speed is nearly constant; next the shock accelerates as it leaves the clumpy region; finally it moves at a constant speed close to its initial speed. Turbulence is generated in the post-shock flow as the shock sweeps through the clumpy region. Clouds exposed to turbulence can be destroyed more rapidly than a similar cloud in an "isolated" environment. The lifetime of a downstream cloud decreases with increasing cloud-to-intercloud mass ratio. We briefly discuss the significance of these results for starburst superwinds and galaxy evolution.Comment: 17 pages, 19 figures, accepted for publication in MNRA

Study of morphocytochemical and immunophenotypic features of acute leukemia stem cells

The immunophenotypic profile of hematopoietic stem cells (HSC) and hematopoietic precursor cells as well as leukemic stem cells (LSC) has been extensively studied in several laboratories worldwide. The results of our studies suggest that the standard panel for classification of acute leukemias should be supplemented with several new markers allowing us to identify more precisely the different forms of the leukemias being of the closely related origin, for example AML M6b and AML M7. The common bipotent LSC in AML M7 of low grade and AML M6b may exist analogous to precursor cell common for megakaryocytopoiesis and erythropoiesis. We have also found the similarity between blast cells in pro-B-ALL [t (4;11), 11q23] and AML M5a [t (9;11), 11q23]. Such similarity of immunophenotype and cytogenetic abnormalities in blast cells in pro-B-ALL and AML M5a may be considered as hint explaining the cases of AML M5a as a recurrence of leukemia in children with originally diagnosed pro-B-ALL.Иммунофенотипический профиль стволовых лейкемических клеток (СЛК) интенсивно изучают в ряде лабораторий мира. Результаты данного исследования подтверждают, что стандартная панель для классификации острых лейкозов (ОЛ) должна быть дополнена рядом новых маркеров. Это позволяет более точно идентифицировать близкие по происхождению формы ОЛ, например ОМЛ М6b и ОМЛ М7. Предполагается существование общей низкодифференцированной бипотентной ЛСК при ОМЛ М7 и ОМЛ М6b, подобной нормальной общей клетке-предшественнице мегакариоцитопоэза и эритропоэза. Установлено также сходство бластных клеток при про-В-ОЛЛ с перестройкой хромосомного участка 11q23 и транслокацией (4;11) и бластных клеток при ОМЛ М5а c перестройкой того же хромосомного участка 11q23 и транслокацией (9;11). Подобное сходство иммунофенотипа и цитогенетических аномалий при указанных 2 формах ОЛ объясняет появление бластов с фенотипом ОМЛ М5а при рецидиве заболевания у детей, у которых ранее был диагностирован про-В-ОЛЛ