Electrical Discharge in a Cavitating Liquid under an Ultrasound Field.

A theoretical model for an electrical discharge in a cavitating liquid is developed and compared with experiments for the optimization of the water treatment device. The calculations based on solution of the Noltingk─Neppiras equation support the hypothesis that the electric field promotes the formation of vapor microchannels inside a liquid gap between the electrodes, where at a low gas pressure Paschen's conditions of rupture and abnormal glow discharge maintenance in those microchannels are fulfilled. Theoretical analysis of the cavitation processes and the discharge formation processes is in qualitative agreement with the experimental data obtained in this work in a water treatment device using a hydrodynamic emitter. The following graphic illustrates the experimental setup: (1) feeding tank, (2) hydrodynamic emitter, (3) zone of cavitation inside the plasma reactor, (4) high-frequency generator of electric impulses, and (5) outlet.

Differences in the Differentiation Potential and Relative Levels of Gene Expression in the Bone Marrow-Derived Fibroblast Colony-Forming Units in Patients during the Onset of Aplastic Anemia Depending on the Disease Severity.

The differentiation potential of individual clones of fibroblast CFU (CFU-F) was studied and the relative expression level of genes was analyzed in the culture of CFU-F from the bone marrow in patients with non-severe and severe forms of aplastic anemia at the onset of the disease. The differentiation potential of CFU-F clones was determined by the relative expression of marker genes using quantitative PCR. In aplastic anemia, the ratio of CFU-F clones with different differentiation potential changes, but the molecular mechanisms of this phenomenon are different in non-severe and severe aplastic anemia. In the culture of CFU-F in non-severe and severe aplastic anemia, the relative expression level of genes associated with the maintenance of the hematopoietic stem cell in the bone marrow niche changes, but the decrease in the expression of immunoregulatory genes occurs in severe form only, which may reflect differences in the pathogenesis of non-severe and severe aplastic anemia.

Bone Marrow Multipotent Mesenchymal Stromal Cells from Patients with Aplastic Anemia Retain Their Ability to Support Hematopoietic Precursors despite Pronounced Changes in Gene Expression.

The properties of bone marrow-derived multipotent mesenchymal stromal cells (MSC) of patients with aplastic anemia at the onset of the disease are studied insufficiently. The aim of this work was to test the ability of MSC from patients with aplastic anemia to maintain hematopoietic precursors and to analyze the expression of genes associated with hematopoiesis and immune response. The ability of MSC to maintain hematopoietic precursors was determined by counting cobblestone area-forming cells; gene expression was analyzed by quantitative PCR. It was shown that MSC of patients with aplastic anemia preserve their ability to maintain hematopoietic precursors. Pronounced changes in the expression of the VEGFA and ANGPT1 genes were found. MSC from aplastic anemia patients with PNH clone significantly differ from those from aplastic anemia patients without PNH clone in terms of the expression of the SDF1, IL1R, and VEGFA genes. Changes in gene expression can be associated with the pathogenesis of the disease.

[Immunosupressive therapy of aplastic anemia patients: successes and failures (single center experiment 2007-2016)].

Treatment programs for patients with acquired aplastic anemia include two main therapeutic options: allogeneic bone marrow transplantation and combined immunosuppressive therapy (IST). However, combined IST remains the method of choice for most adult AA patients. This study included 120 AA patients who received IST at the National Research Center for Hematology in 20072016. The analysis was applied to 120 patients. Median age was 25 (1765) years, M/F: 66/54, SAA/NSAA: 66%/34%. Effectiveness of IST was carried out in 120 patients with AA. This group did not include 8 SAA patients who died during the first 3 months from the start of treatment from severe infectious complications (early deaths 6.2%) and 2 AA patients who dropped out of surveillance. The observation time was 55 (6120) months. Paroxysmal nocturnal hemoglobinuria (PNH clone) was detected in 67% of AA patients. The median PNH clone size (granulocytes) was 2.5 (0.0199.5)%. The treatment was according to the classical protocol of combined IST: horse antithymocytic globulin and cyclosporin A. Most of patients (87%) responded to combined immunosuppressive therapy. To achieve a positive response, it was sufficient to conduct one course of ATG to 64% of patients, two courses of ATG 24% of patients and 2% of patients responded only after the third course of ATG. A positive response after the first course was obtained in 64% of patients included in the analysis. Most of the responding patients (93%) achieve a positive response after 36 months from the start of treatment. Therefore, the 3rd6th months after the first course of ATG in the absence of an answer to the first line of therapy can be considered the optimal time for the second course of ATG. This tactic allows to get an answer in another 58% of patients who did not respond to the first course of ATG. The probability of an overall 10-year survival rate was 90% (95% confidence interval 83.696.2).

[The dynamics of paroxysmal nocturnal hemoglobinuria clone in patients with aplastic anemia in process of immune suppressive therapy].

The implementation of principles of highly sensitive flow cytometry into diagnostic of paroxysmal nocturnal hemoglobinuria increased rate of detection of paroxysmal nocturnal hemoglobinuria clone in patients with aplastic anemia already at early stages of diagnosis establishment (up to 79%). However, detection of paroxysmal nocturnal hemoglobinuria clone attracts interest not only from point of view of progression in % of patients with aplastic anemia). The occurrence of paroxysmal nocturnal hemoglobinuria clone in patients with aplastic anemia can be accompanied by hidden disorders of haemopoesis with increasing risk in conditions of proliferative stress. Hence, it is necessary to monitor the given clone during all period of observation. The study is a prospective investigation analyzing dynamics of paroxysmal nocturnal hemoglobinuria clone in process of immune suppressive therapy applied to 44 patients with aplastic anemia. The mentioned clone was initially detected in 59.6% of patients. The median of observation amounted to 27 (9-48) months. Depending on size of granulocytic paroxysmal nocturnal hemoglobinuria clone patients were allocated in four conditional groups: group I - from 0.01% to 0.99% (n=11); group II - from 1% to 9.99% (n=8); group III - from10% to 49.9% (n=4); group IV - from 50% and more (n=5). In the course of study the differently directed dynamics of paroxysmal nocturnal hemoglobinuria clone was revealed. In 3 out of 11 patients from group I median of paroxysmal nocturnal hemoglobinuria clone increased from minor values (less than 1%) to 3.55%; at that in one patient occurred total elimination of paroxysmal nocturnal hemoglobinuria clone to 12th month of observation. The noticeable unidirectional dynamics was established in patients of group III: already to 3d month of observation, simultaneously with becoming of remission, median of size of paroxysmal nocturnal hemoglobinuria clone in group diminished from 22.9% (18.39%-24.77%) to 5.6% (1.5%-6.7%). Among patients of groups II and IV paroxysmal nocturnal hemoglobinuria clone remained stable. The development of hemolytic form of paroxysmal nocturnal hemoglobinuria was observed in all patients of group IV i.e. in 18% of patients with aplastic anemia with primarily detected paroxysmal nocturnal hemoglobinuria clone. In the process of observation, in 37% of patients with aplastic anemia without primarily detected paroxysmal nocturnal hemoglobinuria clone its occurrence and persistence (median - 0.34% (0.1%-6.2%)) was noticed. According to the results of study, alteration of sizes of paroxysmal nocturnal hemoglobinuria clone or its occurrence develop in case of response to ISP and, most probably, depend on advantage of growth in the process of repair of normal (GPI positive) or clonal (GPI negative) hemopoiesis. To acquire more reliable conclusions will be possible through development of techniques of molecular diagnostic simultaneously with dynamic observation of course of disease in the given patients.