Mechanical and signaling responses of unloaded rat soleus muscle to chronically elevated ß-myosin activity.

It has been reported that muscle functional unloading is accompanied by an increase in motoneuronal excitability despite the elimination of afferent input. Thus, we hypothesized that pharmacological potentiation of spontaneous contractile soleus muscle activity during hindlimb unloading could activate anabolic signaling pathways and prevent the loss of muscle mass and strength. To investigate these aspects and underlying molecular mechanisms, we used ß-myosin allosteric effector Omecamtiv Mekarbil (OM). We found that OM partially prevented the loss of isometric strength and intrinsic stiffness of the soleus muscle after two weeks of disuse. Notably, OM was able to attenuate the unloading-induced decrease in the rate of muscle protein synthesis (MPS). At the same time, the use of drug neither prevented the reduction in the markers of translational capacity (18S and 28S rRNA) nor activation of the ubiquitin-proteosomal system, which is evidenced by a decrease in the cross-sectional area of fast and slow muscle fibers. These results suggest that chemically-induced increase in low-intensity spontaneous contractions of the soleus muscle during functional unloading creates prerequisites for protein synthesis. At the same time, it should be assumed that the use of OM is advisable with pharmacological drugs that inhibit the expression of ubiquitin ligases.

[Multiple myeloma: response to treatment and survival of patients according to the interim analysis of the Russian observational, retrospective-prospective, multicenter cohort study (MULTISPECT)].

AIM: The primary objective of the interim analysis of the MULTISPECT study was to evaluate the short-term efficacy of the treatment and long-term outcomes in cohorts of primary and pretreated patients with multiple myeloma (MM) receiving treatment in actual clinical practice in various regions of the Russian Federation. Secondary objectives were a description of the main characteristics of patients; analysis of the most commonly used therapy regimens of the 1st and later lines and the sequence of their changes; evaluation of the response to therapy. Additional objectives included evaluation of the effect of the new COVID-19 coronavirus infection on the course of MM in patients. MATERIALS AND METHODS: The study is an observational retrospective-prospective multicenter cohort study. For its implementation, a structured database of patients with MM was used, provided by hematologists of the centers affiliated for the study. RESULTS: The study included 1,294 patients (cohort 1 806, cohort 2 488). In both cohorts, patients aged 6069 years were in the majority. 3 lines of therapy (L1, L2, L3) were used for cohort 1; in cohort 2, the 4th line of therapy was also used in 2 patients. The therapy regimens were analyzed for 290 (22.41%) of all patients in the study. Responses to therapy were analyzed for 214 patients of cohort 1 and 109 patients of cohort 2. Autologous and allogeneic hematopoietic stem cell transplantations were carried out for a limited proportion of patients in both cohorts. At the end of the study and upon presentation of its results, the status of patients was the following: 96% of patients in cohort 1 and 89% in cohort 2 were alive. The therapy regimens in both cohorts were characterized by variability. The most commonly used regimens in each of the lines of therapy have been identified. The most used therapy regimen in patients with MM of both cohorts was the VCD-regime. Rd-regime in cohort 1 and RD-regime in cohort 2 were the second most frequent used regimens. In patients of both cohorts, the therapy regimens including Bortezomib were most often used. CONCLUSION: The variety of therapy regimens used to treat MM in actual clinical practice may be due to the factors of availability of new medicines and updated recommendations for the treatment of the disease. Further, in the context of this study, a more detailed analysis of the efficacy of certain therapy regimens in the 1st and later lines on progression free survival and overall survival of MM patients should be carried out.

[The efficacy and safety of eculizumab biosimilar in patients with paroxysmal nocturnal hemoglobinuria. Results of a phase III randomized open-label comparative clinical trial].

AIM: To establish the equivalent efficacy and comparable safety profile of biosimilar Acveris and referent eculizumab product Soliris used for the treatment of paroxysmal nocturnal hemoglobinuria (PNH). MATERIALS AND METHODS: Were included in the phase III multicenter 28 PNH patients, open-label clinical trial. Participants were randomized (1:1) into 2 treatment groups: investigational product (Acveris, n=14) and referent product (Soliris, n=14). Patients received eculizumab as the intravenous infusion 600 mg once a week during the first 4 weeks, 900 mg at week 5 and then 900 mg every 14 days (2 days) up to week 27 of the study. The efficacy, pharmacokinetics, pharmacodynamics, safety and immunogenicity of the compared products were analyzed after the end of 27 weeks of the study. The primary efficacy endpoint was the area under the curve LDH concentrationtime (AUCLDH) throughout the study period weeks 527. RESULTS: The difference between the mean AUCLDH values between the Acveris and Soliris groups was 5380.0 [-38 773.87; 49 533.87] U/ldays. The 95% CI limits for the difference in mean AUCLDH values between the groups fit the preset 95% CI [-146 500.9146 500.9] U/ldays and establish the equivalent efficacy of the biosimilar and referent product according to the primary efficacy endpoint. The safety profile of both Acveris and Soliris was expected and comparable according to the proportion of patients with adverse events. The formation of binding antibodies to eculizumab was not detected in both the groups. CONCLUSION: The study established the equivalent efficacy of biosimilar product Acveris and referent eculizumab product with the evidence of effective suppression of intravascular hemolysis in PNH patients along with a comparable favorable safety profile.

[Results of phase Ib open multicenter clinical trial of the safety, pharmacokinetics and pharmacodynamics of first biosimilar of eculizumab in untreated patients with paroxysmal nocturnal hemoglobinuria during induction of therapy].

Currently, the main pathogenetic method for the treatment of paroxysmal nocturnal hemoglobinuria (PNH) is the treatment with recombinant monoclonal antibodies that block the C5 component of the complement system. Eculizumab is the first biotechnological drug, which is a monoclonal antibody, with proven clinical efficacy and safety for the treatment of patients with PNH, which is used in world clinical practice. In Russia, in the framework of the state program Development of the pharmaceutical and medical industry for 20132020 was developed Elizaria (JSC GENERIUM) the first biosimilar of the original drug eculizumab. AIM: To evaluate the pharmacokinetic and pharmacodynamic parameters, as well as safety and immunogenicity parameters of the drug Elizara in the induction phase of therapy in previously untreated patients with PNH. MATERIALS AND METHODS: The study included 11 patients with PNH aged 26 to 75 years who had not previously received eculizumab. Each of the study participants was injected with the studied drug Elizaria at a dose of 600 mg intravenously once a week for 4 weeks. RESULTS: During the clinical study, it was noted that the concentration of the studied drug significantly increased by the time the infusion was completed and then gradually decreased to a minimum at the end of the dosing interval. The average concentration of eculizumab 5 minutes before the administration of the study drug at all visits exceeded 35 g/ml, the minimum concentration sufficient to completely inhibit intravascular hemolysis in patients with PNH. The pharmacodynamic efficacy of the drug Elizaria was confirmed by a decrease in the concentration of the membrane-attack complex (MAC) after the first infusion of the drug was maintained at stable levels until visit 5. A persistent decrease in the level of MAC and a four-fold decrease in the average values of lactate dehydrogenase to visit 5 from 1286.4 to 280.9 U/l demonstrated a marked decrease in activity and stabilization of the hemolytic process against the background of the induction of therapy with Elizaria at a dose of 600 mg once a week and confirmed the effecacy of the study drug. Among the 9 adverse events, only 5 had a relationship with the studied drug, including one serious adverse event in the form of an allergic reaction, which, according to the researcher, had a possible cause-effect relationship with the infusion of the studied drug. In 2 patients, low-titer binding anti-drug antibodies were detected without neutralizing activity during treatment with the studied drug, which may indicate its low immunogenicity. CONCLUSION: The study evaluated the pharmacokinetic and pharmacodynamic properties of the drug Elizaria in the regimen of induction therapy in previously untreated patients with PNH, confirming its efficacy. The study demonstrated the safety and low immunogenicity of the study drug.

Hypochlorite-Induced Damage of Plasminogen Molecules: Structural-Functional Disturbance.

Plasminogen, the precursor of plasmin, is a serine protease that plays a fundamental role in the intravascular thrombolysis. For the first time, by using high-resolution mass spectrometry, data on the oxidative modifications of the plasminogen molecule under induced oxidation were obtained. The FTIR data show that, under oxidation on the protein, its secondary structure also undergoes the rearrangements. The high tolerance of plasminogen to oxidation can be due to both the closed conformation and the ability of some Met residues to serve as ROS trap.

The Iron State in Spleen and Liver Tissues from Patients with Hematological Malignancies Studied Using Magnetization Measurements and Mössbauer Spectroscopy.

In this overview, we present the results of the study of spleen and liver tissues taken from healthy donors in comparison with those from patients with (i) non-Hodgkin B-cell lymphomas, namely, mantle cell lymphoma and marginal zone B-cell lymphoma, (ii) acute myeloid leukemia, and (iii) primary myelofibrosis. The study was carried out using Mössbauer spectroscopy and magnetization measurements for the analysis of ferritin-like iron in spleen and liver tissues. Magnetization measurements demonstrated small differences in the saturation magnetic moments and revealed additional paramagnetic components. Two liver samples demonstrated unusual behavior of the magnetic moment when the zero-field-cooled curve was over the field-cooled curve in the temperature range between ~40 and ~70 K. Relative iron content variations in the tissue cells as well as small variations in the 57Fe hyperfine parameters were demonstrated for healthy and patients' spleen and liver tissues on the base of measured Mössbauer spectra. The results obtained permit us to suggest small differences in the ferritin iron core structure in spleen and liver tissues from healthy donors and patients with hematological malignancies.

[Adult B-cell acute lymphoblastic leukemias: Conclusions of the Russian prospective multicenter study ALL-2009]. / Ostrye V-limfoblastnye leikozy vzroslykh: vyvody iz Rossiiskogo prospektivnogo mnogotsentrovogo issledovaniia OLL-2009.

AIM: To analyze the efficiency and reproducibility of the ALL-2009 protocol within the Russian prospective multicenter study based on different principles of cytostatic effects (non-intensive, but continuous cytotoxic treatment and a small number of allogeneic hematopoietic stem cells). SUBJECTS AND METHODS: The ALL-2009 (NCT01193933) study conducted in April 2009 to December 2016 included 194 patients (95 males and 99 females) aged 15 to 55 years (median age 28 years) with Ph-negative B-cell acute lymphoblastic leukemia (ALL). There was early pre-B-cell ALL in 54 patients, common ALL in 101, pre-B ALL in 39, initial leukocytosis in 9.4·109/l (0.4-899.0), lactate dehydrogenase in 901 IU (31-13 059), an initial central nervous system lesion in 17 (8.7%), mediastinal injury in 3 (1.5%), and splenomegaly in 111 (57.2%). The results of standard cytogenetic analysis are known in 113 (60.4%) patients. Normal karyotypes were detected in 49 (54.5%) out of the patients; t(4;11) in 9 (5.4%), t(1;19) in 2 (1.2%), and other karyotypic abnormalities in 53 (46.9%). Thirteen (7.8%) patients underwent allogeneic hematopoietic stem cell transplantation in first complete remission (CR); their proportion did not differ in the federal and regional centers. RESULTS: The frequency of CR achievement was the same in the federal and regional centers and generally amounted to 87.5%. Early (8.8%) and CR (9.6%) mortality rates remained high despite the low aggressiveness of cytotoxic action, necessitating the improvement of auxiliary treatment. The five-year overall survival (OS) rates vary considerably in the federal and regional centers (72.6 and 43.8%), the relapse-free survival (RFS) (70.2 and 53.4%) and recurrence risk (23.1 and 36.5%) are comparable. This suggests that the non-intensive, but continuous exposure principle built in the ALL-2009 protocol makes it possible to reproduce the envisaged treatment program and to achieve satisfactory results. CONCLUSION: The ALL-2009 protocol allows both the federal and regional centers to obtain the long-term results comparable with those of current foreign studies: OS (54.2%), RFS (56.5%); and relapse risk (35.4%). Multivariate analysis has identified age (over 30 years), initial leukocytosis (30·109/l and more) and t(4;11) among the main clinical prognostic factors. Gene mutation detection evaluated in a small number of patients (8/36) is not a poor prognostic sign. There is a need for further investigations with centralized evaluation of the mutation status of leukemic cells and the clearance of minimal residual disease.

[Acute Ph-negative lymphoblastic leukemias in adults: Risk factors in the use of the ALL-2009 protocol]. / Ostrye Ph-negativnye limfoblastnye leikozy vzroslykh: faktory riska pri ispol'zovanii protokola OLL-2009.

AIM: to analyze well-known risk factors (RFs), such as age, immunophenotype, baseline leukocytosis, enhanced lactate dehydrogenase (LDH) activity, time to achieve complete remission, a risk group, and cytogenetic abnormalities) in patients with acute lymphoblastic leukemia (ALL) in the use of the ALL-2009 protocol. SUBJECTS AND METHODS: The protocol covered 298 patients (137 women (including 13 pregnant women) and 161 men) aged 15 to 55 years (median age 28 years) with Ph-negative ALL. The phenotype was unknown in 6 patients. Three (1%) were ascertained to have a biphenotypic variant. 182 (62.4%) patients were found to have B-cell ALL (early pre-B ALL (n=51); common ALL (n=92), and pre-B ALL (n=39); 107 (36.6%) patients had T-cell ALL (early T-ALL (n=56); thymic T-ALL (n=41), and mature T-ALL (n=10). According to the baseline clinical and laboratory parameters (leukocytosis of 30·109/l and more for B-ALL; and that of 100·109/l and more for T-ALL; phenotype В-I for B-ALL, phenotype Т-I-II-IV for T-ALL; LDH activity was more than twice the normal values; the presence of translocation t(4;11)), the high-risk group included most patients with B-ALL (n=110 (72.8%)) and T-ALL (n=76 (76%)). Thirty-five patients with T-ALL underwent autologous bone marrow transplantation (BMT). Allogeneic BMT was performed in 18 (7%) of the 258 patients who had undergone an induction phase. RESULTS: Five-year overall survival for all the patients included in the investigation was 59%; relapse-free survival was 65%, which was significantly different in the patients with B-ALL and in those with T-ALL: the overall survival rates were 53.3 and 67.5% (p=0.1); the relapse-free survival was 56 and 79% (p=0.005), respectively. Multivariate analysis including the well-known RFs demonstrated that the latter for T-ALL were of no independent prognostic value and only the patient's age was identified for B-ALL (p=0.013). CONCLUSION: A lower chemotherapeutic load and a small number of allogeneic BMTs did not affect total positive treatment results in adult patients with ALL, by complying with the principle achieving the continuity of cytostatic effects and by preserving the total cytostatic loading dose. The results of the Russian investigation casts some doubt on the necessity of using very intensive consolidation cycles and performing a large number of allogeneic BMTs in adult patients with ALL.

[Autologous hematopoietic stem cell transplantation as late high-dose consolidation in adult patients with T-cell lymphoblastic leukemias: Results of a Russian multicenter study].

AIM: To analyze the efficiency of the ALL-2009 protocol (ClinicalTrials.gov NCT01 193933) in patients with T-cell leukemias, particularly the role of autologous hematopoietic stem cell transplantation (auto-HSCT) after non-myeloablative BEAM conditioning, followed by maintenance therapy. SUBJECTS AND METHODS: Since 2009, the ALL-2009 study has enrolled 90 patients with T-cell acute lymphoblastic leukemia (T-ALL), the treatment results were assessed in 86 patients: 6 and 28 patients underwent allogeneic HSCT and auto-HSCT, respectively. A landmark analysis was used to compare survival rates in patients who had undergone auto-HSCT and in those who had not. For this, the median time from complete remission to the date of auto-HSCT was determined (the median was 6 months). Then to compare with the auto-HSCT group, only 27 patients who had been in complete remission for 6 months or more were included in a chemotherapy group. RESULTS: The achievement of complete remission in patients with thymic T-ALL (100%) was significantly higher than in those with early (85.7%) or mature (70%) variants. The patients with early and mature T-ALL as compared to those with thymic T-ALL showed high death rates in the remission induction (7.4 and 10% versus 0) and the patients with mature T-ALL had a.higher proportion of refractory forms (20% versus 0). The 5-year overall and relapse-free survival rates in all the T-ALL patients were 66 and 76%, respectively. After auto-HSCT, the risk of recurrence was 0% versus 21% after chemotherapy (p=0.03). The relapse-free survival rates significantly differed in the auto-HSCT and non-auto-HSCT groups: 100 and 66%, respectively (p=0.047). CONCLUSION: The long-term survival rates obtained during this multicenter study in the T-ALL patients treated according to the ALL-2009 protocol, the basis for which is the principle of continuity of cytostatic effects, are exclusively optimistic. Late consolidation with auto-HSCT following non-myeloablative BEAM conditioning, followed by maintenance therapy, considerably reduces the risk of recurrence.

[Russian experts' clinical guidelines for acute myeloid leukemia treatment in patients less than 60 years of age].

The purpose of the paper is to present Russian experts' consolidated opinion about acute myeloid leukemia (AML) treatment in adult patients aged less than 60 years. The guidelines have been elaborated having regard to foreign publications and Russian experience, on the basis of global and Russian clinical trials to treat AML and to define indications for allogeneic bone marrow transplantation in patients during first complete remission.

[Endogenous content of the nitric oxide in the cell layers of the eye retina].

Nitric oxide is a universal molecule that regulates many different functions in an organism. In the eye retina nitric oxide plays both a regulatory role by modulation of the synaptic transmission between photoreceptors and bipolar cells and a toxic role in apoptosis induction in the outer nuclear layer and in the layer of ganglion cells. In this paper there has been made the first attempt to estimate the endogenous NO concentration in retina layers in vivo. The concentration of the nitric oxide was determined by two indepen- dent techniques: ESR spectrometry using spin trap for in vivo determination and NO-sensitive microelectrode for in situ determination in the survival isolated frog retina. The distinct NO con- centration was detected only in the ganglion cells layer (~0.25 µM) and in the inner segments layer of the photoreceptors (~0.6 µM). The activity and the kinetic characteristic of the NO-synthase localized in the same layers were also determined. Key words: retina cells layers, nitric oxide, ESR, NO-sensitive microelectrodes.

Mössbauer spectroscopy of the iron cores in human liver ferritin, ferritin in normal human spleen and ferritin in spleen from patient with primary myelofibrosis: preliminary results of comparative analysis.

Comparative study of human liver ferritin and spleen tissues from healthy human and patient with primary myelofibrosis was carried out using Mössbauer spectroscopy with a high velocity resolution at 295 and 90 K and with a low velocity resolution at 20 K. The results obtained demonstrated that the iron content in patient's spleen in the form of iron storage proteins was about ten times larger than that in normal tissue. However, in the case of patient with primary myelofibrosis the magnetic anisotropy energy barrier differed from that in normal case and, probably, the iron core size was supposed to be slightly larger than that in both normal spleen tissue and normal human liver ferritin in contrast to well-known data for iron overload in patients with thalassemia accompanied by the iron-core size increase. Therefore, the iron overload in the case of patient with primary myelofibrosis may be related to increase in the ferritin content mainly. It was also found that Mössbauer hyperfine parameters for normal and patient's spleen and normal human liver ferritin demonstrated some small differences related, probably, to some small structural variations in the ferritin iron cores of patient's spleen.

[Treatment for acute promyelocytic leukemia during pregnancy].

AIM: To study the experience in managing patients with acute promyelocytic leukemia (APL) diagnosed in different periods of pregnancy. SUBJECTS AND METHODS: Nine women with APL were treated in 1998-2013. When APL was diagnosed in the first trimester of pregnancy, the latter was terminated (n = 1); when its diagnosis was made in the second trimester, chemotherapy (CT) followed by delivery (D) was performed (n = 3); when it was done in the third trimester, D followed by CT was done in relation to gestational age (n = 2) or these were performed at a later gestational age (n = 1). APL was treated in 5 and 1 patients according to the AIDA protocol and the 7+3 plus ATRA one, respectively. RESULTS: All the patients with APL achieved remission after the first cycle of induction CT; 5 of the 6 patients did at the moment of delivery; one patient underwent emergency delivery during cytopenia after the cycle. The gestational age at delivery after CT was 34 (34-40) weeks. Spontaneous term labor occurred in 2 patients at an obstetric hospital. Cesarean section was made in 4 of the 6 patients. All babies were born alive, healthy, and without developmental abnormalities. Their age at the time of analyzing the results was 2.5 months to 15 years. Four of the 9 patients are presently alive. Late recurrences occurred in 3 (33%) patients. The median overall survival is 26 (0.25-128) months; the median relapse-free survival is 17.5 (0-127) months. CONCLUSION: APL treatment in pregnant women, which is aimed at saving two lives, is effective and reasonable.

[The first results of treatment for adult acute myeloid leukemia according to the AML-01.10 protocol of the Research Group of the Hematology Centers of Russia].

AIM: To give the preliminary results of the AML-01.10 Russian multicenter randomized trial to treat adult acute myeloid leukemia (AML), the basic principle of which is to use high-dose anthracycline antibiotics in induction/consolidation. SUBJECTS AND METHODS: By December 2011, 145 patients with AML had been randomized from 18 hematology centers of 15 cities and towns of the Russian Federation; the median age of all the patients was 44 years. Seventy-one patients were analyzed in August 2011 (a 1.5-year follow-up). RESULTS: The efficiency of 2 courses 7+3 using high-dose daunorubicin (60 mg/m2 per administration) and continuous infusion of cytarabine during the second course was high and comparable with that in the use of a high-dose HAM protocol as a second induction course and can achieve a complete remission in 74.6%. The protocol toxicity evaluated from its early mortality (11.3%) and its death in complete remission (16.6%) was permissible, particularly by taking into consideration the multicenter pattern of the trial. At the completion of analysis, 53 (68.8%) out of the 77 patients on whom the data on their vital status were available were alive. In this follow-up period, the frequency of recurrences was 19.2% (10/52). Only 3 (4.2%) patients out of the 71 patients in whom the efficiency of the protocol had been completely evaluated underwent allogeneic bone marrow transplantation. CONCLUSION: The total high dose (720 mg/m2) of anthracycline antibiotics, which is used in the period of induction and consolidation, determines the long periods of myelosuppression and intercourse intervals. Protocol deviations (no course of consolidation therapy, lower-dose idarubicin during consolidation therapy, a course of low-dose cytarabine, between the courses of induction and consolidation chemotherapy, and very long intercourse intervals) were recorded in a total of 20 (28%) patients.

[Modification of the nitric oxide concentration regulates the development of the apoptosis in the eye retina].

Using model elaborated it was shown that the retinal ischemia initiated the development of the apoptosis in the inner layers of the retina. Administration of NOS inhibitor prevented the development of the apoptosis in the retina. To ascertain if nitric oxide could induce the retinal apoptosis by itself the nontoxic donor of nitric oxide (dinitrosyl iron complex) was injected intravitreally. Administration of DNIC in low concentrations induced the development of the apoptosis in the same retinal layers as in ischemia. The injection of dinitrosyl iron complex at the higher concentration resulted in the decrease of the apoptosis level. Administration of dinitrosyl iron complex with excess of glutathione didn't lead to the development of the retinal apoptosis. The obtained data demonstrates the neurotoxic properties of the excess of nitric oxide in the retina.

[First results of Ph-negative acute lymphoblastic leukemia therapy of adults according to the protocol of Research Group of Russian Hematological Centers ALL-2009].

AIM: To review results of 2-year experience in execution of the protocol on the treatment of adult acute Ph-negative lymphoblastic leukemia ALL-2009. MATERIAL AND METHODS: Of 111 patients registered in the study from November 2008 to December 2010 the analysis covered 96 patients from 23 hematological centers in 18 towns of the RF. RESULTS: Treatment according to the Protocol ALL-2009 resulted in achievement of a complete remission in 91.2% patients with low early lethality of 5.5%. Postremission lethality fell to 3.7% versus previous studies (22%). Overall 2-year survival and recurrence-free survival reached 77.6 and 78.4%, respectively. Detection of any chromosomic aberrations significantly affected recurrence-free survival: 74 vs 100% in patients with normal karyotype. CONCLUSION: Protocol All-2009 demonstrates high efficacy in moderate toxicity and good reproducibility in any hematologic center.

Heme iron state in various oxyhemoglobins probed using Mössbauer spectroscopy with a high velocity resolution.

A comparative study of oxyhemoglobins from pig, rabbit, normal human and patients with blood system malignant diseases was performed using Mössbauer spectroscopy with a high velocity resolution at 90 K. Mössbauer spectra were fitted with the help of two models: using one quadrupole doublet (model of equivalent iron electronic structure in α- and ß-subunits of hemoglobins) and superposition of two quadrupole doublets (model of non-equivalent iron electronic structure in α- and ß-subunits of hemoglobins). The results obtained using both models demonstrated small variations of hyperfine parameters that were related to the heme iron state variation in different hemoglobins. These results were compared with structural and functional differences of the hemoglobins investigated.

[Nitrites can be reduced in retinal vessels during hypoxia and protect the retina against ischemia and apoptosis].

The possibility and the mechanism of the reduction of nitrites in retinal vessels under the acute hypoxia in vivo have been investigated. An experimental model of the rat retina ischemia was elaborated using the laser coagulation of retinal vessels. It was demonstrated that the vessel thrombosis does not occur if the nitrite concentration in the vessels is increased. It was proposed that, under acute hypoxia, nitrites are reduced to NO, which results in a drastic vasodilatation. Considering that the effect takes less than a minute, this reduction cannot be due to hypoxic acidosis but is more likely associated with NO reduction by heme proteins. It was found that the increased concentration of nitrites protects the retina from the development of ischemia progress and that the preliminary administration of nitrites prevents apoptosis in the retina and a decrease in its photoelectric activity.

[Toxicity of different treatment protocols for acute myeloid leukemias in adults: the results of four Russian multicenter studies].

AIM: To comparatively analyze the toxicity of 4 treatment protocols in patients with acute myeloid leukemia (AML), which were used in the Russian multicenter center in 1992 to 2009. MATERIALS AND METHODS: The information obtained in 4 Russian multicenter studies conducted in 33 hematology departments of 26 cities and towns of the Russian Federation in 1992 to 2009 was analyzed. Randomization was made in 243 patients with AML (median age 38 years) in 1992-1995, 396 patients (median age 39 years) in 1995-1999, 392 patients (median age 39 years) in 2001-2006, and 137 patients (median age 40 years) in 2006-2009. The analysis excluded patients with acute promyelocytic leukemias who were recruited in the AML-92 and AML-95 studies. These patients' statutory forms adequately filled in were 60-70% therefore toxicity was analyzed on the basis of the data of 631 patients. RESULTS: The baseline clinical and laboratory parameters in the patients enrolled in the studies in different years slightly differ in the count of leukocytes at the onset of the disease and in the level of lactate dehydrogenase (LDH): the recent studies revealed a larger number of high-risk group patients (leukocytes more than 30 10(9)(/l; LDH more than 500 units) possibly due to the later diagnosis of AML. During the studies, the number of complete remissions remained as before (55%) after the first course and increased from 65 to 78% after the second course using cytosine arabinoside in high doses. Despite treatment intensification, mortality in the induction period remained as before (19-21%). Remission mortality decreased from 18 to 10-13%. The long-term results of using the aggressive therapy did not differ from those obtained during the standard treatment protocols. The duration of leucopenia after standard induction courses during the all studies remained equal (17-19 days); the exclusion was a HAM course as the second induction course after which the duration of neutropenia was much more than that of the standard course (17 and 10 days, respectively). During the study years, there was an increase in platelet transfusion volumes (from 20 to 53 doses during the first course and from 7 to 28 doses during the second course) and a reduction in the percentage of severe hemorrhagic complications. The incidence of pneumonias remained at the same level (40-50%) during the induction courses and that of septic complications and necrotic enteropathy considerably decreased from 40-46 to 17-19%. The incidence of invasive aspergillosis during the current programs from AML treatment was 10% (two induction courses), that of invasive candidiasis was 4.7% (two induction courses). CONCLUSION; The long-term results of treatment for AML were virtually unchanged regardless significant therapy intensification. Mortality remained high during induction treatment and in the postremission period. Its cause is severe infectious complications developing during myelotoxic agranulocytosis. The results of the analysis provide the basis for developing a new AML treatment protocol that should take into account all the merits and demerits of the previous protocols and provide a toxicity-treatment efficiency balance.

Experimental model of acute ischemia of the retina in rats.

We studied the development of retinal ischemia in rat eye after laser coagulation of blood vessels. Typical signs of ischemia manifested in the retina after 24 h: development of stable retinal edema, decrease in the b/a index (ratio of the electroretinogram b and a-wave amplitudes) to 1-2 units, pronounced disorders in the retinal microcirculation system, leading to ischemia of the inner layers of the retina. The proposed model is convenient for studies of the development of acute retinal ischemia, is easily realized, and reproduces some acute ischemic diseases of the retina.