Characteristics of anthracycline-resistant strains of P388 leukemia

Two strains of P388 murine leukemia with acquired resistance to rubomycin (P388/rm) and its nitroxyl derivative ruboxyl (P388/rx). The rubomycin resistance has been developed by the 14th generation and ruboxyl one-by the 8th generation. The growth kinetic patterns and the cell cycle time of the parent and resistant strains were similar. An increased tumourogenicity of both resistant strains cells was found. The resistance development was accompanied by the appearance of the additional chromosome materials, namely of homogeneously staining region (P388/rx) and of double chromatin bodies (P388/rm). The partial recovery of sensitivity to rubomycin occurred during 36 generations (1 year). Simultaneously the genetic markers have been lost. The recovery of sensitivity to ruboxyl in this period was not observed. The obtained resistant strains possessed the multidrug resistance: the cross resistance of P388/rm and P388/rx to actinomycin D, Vinca alkaloids and colchicine was shown.     

Sensitivity to chemotherapeutic preparations of anthracycline-resistant strains of murine leukemia P388

P388 leukemia strains resistant to rubomycin and ruboxylnitroxyl derivative of rubomycin were studied for their drug sensitivity. The resistant strains exhibited cross resistance to anthracycline antibiotics, vinca alkaloids, actinomycin D, colchicine. The rubomycin-resistant strain gained significantly higher sensitivity (in comparison with the parent strain and the ruboxyl-resistant strain) to six drugs: cisplatin, sarcolisin, dopan, thiophosphamide, degranol, 6-mercaptopurine. The karyotype of the ruboxyl-resistant cells was characterized by the presence of chromosome with homogeneously straining region (HSR). The alteration of the HSR-location was accompanied by the increase of chemotherapeutical sensitivity of the ruboxylresistant strain to the alkylating agents.     

Effects of intracellular Na+/K+ ratio on histone gene expression in ascitic cells of leukemia P-388 and Ehrlich cancer

The intracellular Na+/K+ ratio was studied for its effect on histone genes expression in Ehrlich carcinoma and leukemia P-388 ascites cells. After equilibration with certain Na+/K+ ratio buffers at 0-4 degrees C the cells were treated during 1 h at 37 degrees C with ouabain added to the corresponding medium. Then total RNAs were extracted and analyzed by the reaction of blot-hybridization with histone genes cluster in plasmid p604. The maximal level of histone genes expression in leukemia P-388 cells was observed under conditions when intracellular Na+/K+ ratio corresponded to those at S-phase of the mitotic cycle. In Ehrlich carcinoma ascites cells the expression of histone genes was not dependent on the Na+/K+ ratio. A conclusion is drawn that the intracellular ratio of monovalent cations is one of the possible mechanisms which regulates the gene expression during the mitotic cycle.     

Antineoplastic activity of combinations of cytostatics and dextran-ferrite administered to mice with leukemia P-388

Water solutions of adriblastin, dactinomycin, rosevin, methotrexate, cisplatin, sarcolysine, rubomycin, cyclophosphamide, 5-fluorouracil or ftorafur were combined with dextran ferrite. The obtained compositions were injected i.p. to BDF1 mice 24 hours after they were inoculated with one million of murine P388 leukemic cells. Antitumor activity was fully retained for each of these agents in combination with dextran ferrite.     

Effects of intracellular Na+/K+ ratio on expression of c-fos oncogene and beta-actin gene in ascitic cells of leukemia P-388 and Ehrlich tumor

The intracellular Na+/K+ ratio was studied for its effect on expression gene beta-actin and oncogene c-fos and activity of these genes during the mitotic cycle in ascites cells of leukemia P-388 and Ehrlich tumour. It was established that gene beta-actin was activated at high and low ratios of Na+/K+, while c-fos only at high ones. The expression of these genes during the mitotic cell cycle was due to changes in the intracellular Na+/K+ ratio. The obtained data showed an important role of intracellular homeostasis of monovalent cations in regulation of gene expression during the mitotic cell cycle.     

白血病细胞的无丝分裂现象

无丝分裂 (ａｍｉｔｏｓｉｓ) ,又称直接分裂 ,是不同于有丝分裂 (ｍｉｔｏｓｉｓ)的一种细胞分裂方式。无丝分裂时 ,细胞不经有丝分裂周期而直接进行细胞核和细胞质的分裂。无丝分裂常见于原生动物 ,但在动植物细胞中也存在[1,2 ] 。目前对无丝分裂的机制和意义还了解不多 ,报道很少。我们在白血病的超微结构研究中 ,发现急性粒细胞白血病细胞也存在着无丝分裂现象 ,本文对此作初步报道。材料与方法本研究观察了 8例急性粒细胞白血病 (Ｍ1型 )外周血标本。外周血标本为静脉血 4～ 5ｍｌ,肝素抗凝 ,在离心管内离心 (2 0 0 0ｒ ｍｉｎ) 15ｍ…     

含磷化合物对电解液形成曲线的影响

通过对各种含磷化合物形成曲线的比较,研究了含磷化合物对电解液闪火电压的影响。着重对比了含水和非含水体系形成曲线的差异,就曲线的形成原因进行了分析。     

Morphofunctional characteristics of the blast cells in acute myelomonoblastic leukemia

Morphocytochemical and immunological characteristics and indices of the cloning effectiveness were studied in agar cultures. Three types of leukemic cells were found whose ratio in the bone marrow varied in a rather wide range. The lymphoid markers (of cOLL and T-antigens) were detected on blast cells. It is established that histogenetic characteristics of the blast cells determines peculiarities of their growth in the agar culture.     

Different levels of differentiation of blood leukemia cells in patients with chronic lymphoid leukemia

The immunological phenotype of blood leukemic cell samples derived from 52 patients with B-cellular chronic lympholeukemia (B-CLL) was defined with the use of monoclonal antibodies and antisera to differentiation antigens and immunoglobulins. Leukemic cells were divided into 6 groups according to the stages of B-cell lineage differentiation: pre-B-cells, early and late antigen-independent stages and three consecutive antigen-dependent stages of differentiation. It was established that in case of B-CLL phenotypic characteristics of later stages of B-lymphocyte differentiation dominated.     

Ultrastructural organization of the blood lymphoid cells in hairy cell leukemia

The cytochemical, immunological, and ultrastructural peculiarities of the hairy-cell leukemia cells are studied. The hairy cells can be identified by characteristic of ultrastructure of organellae: numerous thin processes on the plasma membrane, large cytoplasmic area, well developed granular endoplasmic reticulum, numerous vesicules and electron dense granules, a well differentiated lobulated nucleus with a large nucleolus in which the granular component predominates.     

Functional changes in the natural killer cells of patients with acute leukemia

The results of study of NKC activity (51Cr release assay, conjugate-forming and lytic activity) in healthy persons and patients with acute leukemia (AL) in active phase and in remission are presented. It has been shown that the depression of the NKC activity in acute phase of AL (6 times as low as in norm) and in remission (3 times as low as in norm) depended upon disturbances of the processes of conjugate formation, lytic and recycling activity. Correlation has been found between percentage of lytic conjugates and that of cytotoxicity. The increase of NKC activity in remission seemed to be due to tendency to normalization of functional state of NK-cells (conjugate-forming and recycling activity).     

Changes in the chemotherapy sensitivity of leukemia L1210 cells during the development of diazan resistance

L 1210 leukemia strain resistant to diazan (L 1210/D1) was studied for its drug sensitivity in comparison with the parent strain. The resistant strain exhibited significantly higher sensitivity to nine drugs: dopan, sarcolysine, apirazidin, cyclophosphane, 6-mercaptopurine, thiophosphamide, rubomycin, vinblastine and vincristine. L 1210/D1 gained cross resistance to four drugs: 1-(2-chloroethyl)-3-(2, 6-dioxy-3-piperidyl)-1-nitrosourea, methotrexate, 5-fluorouracil and ftorafur. The resistant strain sensitivity remained unchanged (in comparison with the parent strain) to seven drugs: degranol, prospidin, nitrosomethylurea, chlorozotocin, deazauridine, bleomycin and L-asparaginase (crasnitine).     

Hematopoietic precursor cells in Wistar rats with acute myeloblastic leukemia

The studies were performed on Wistar rats with acute myeloblastic leukemia induced by a prolonged administration of tritiated water (370 MBq/kg/day-1; an absorbed dose--25.3 Gy) and by repeated pyrogenal injections. A reduction of the pool of polypotent hemopoietic cells (CFUs) with a simultaneous increase of their proliferative activity and a decline of their ability to self-supporting were observed in the leukemia-bearing animals. Populations of CFUdc in DC and of CFUc were reduced in all cases; their colony-forming ability was also found to decrease. All animals with leukemia showed a lowered amount of CFU-BL in the bone marrow and of CFU-TL in the thymus, although the content of these cells in the peripheral blood remained unchanged.     

生物活性因子对白血病细胞超微结构的影响

观察比较不同的生物活性因子对白血病细胞超微结构的影响。方法：（1）诱导、提取、制备人白血病抑癌因子（HLIF）和四种人胚胎组织的低分子活性肽。（2）观察五种不同的生物活性因子对小鼠白血病细胞和人白血病细胞超微结构的变化。结果：五种生物活性因子对小鼠及人白血病细胞均具有抑制作用,超微结构与白血病对照组相比有明显的改变,并有大量的凋亡细胞出现。     

含磷阻燃剂对无卤覆铜板性能的影响

探讨了磷阻燃剂不同用量对覆铜板各项性能的影响及作用机理。适当用量可以改善阻燃、降低热膨胀系数以及介电常数,但会带来吸水率、成本的提升。     

Ultrastructural characteristics of bone marrow subendosteal region cells in T-cell virus-induced leukemia

The experiments were carried out to study hemopoietic and stromal cells of bone marrow subendosteal regions during T-cell lymphomagenesis in AKR mice, using transmission electron microscopy and electron microscopic immunocytochemistry methods. It is shown that the subendosteal region of mice with lympholeukosis is replaced by lymphocytes at different stages of differentiation with certain ultrastructural peculiarities. The association of alkaline-phosphatase positive reticulum cells with granulocytes is destroyed. The alkaline phosphatase activity in reticulum cells of the subendosteal region of mice with spontaneous lympholeukosis is very low or absent. The results obtained may be useful for understanding the AKR lymphomagenesis.     

Expression of Fc- and C3-receptors on membranes of blast cells in myeloblastic leukemia and blast crisis of myelocytic leukemia

The expression of Fc-receptors to immunoglobulins IgG, IgA, IgM, that of FcH-receptor and receptors to C3-components of the complement in peripheral blood blast cells were studied in 11 patients with acute myeloblast leukosis and 10 patients with chronic granulocytic leukemia at the stage of blast transformation. The data obtained show the lower level of differentiation and functional activity of blast cells in patients with acute myeloblast leukemia while in chronic granulocytic leukemia a degree of expression of surface receptor on myeloblasts is close to the data obtained in the study of membrane receptors on promyelocytes and myelocytes of healthy persons.     

On the resilience of P2P botnet footprints in the presence of legitimate P2P traffic

Botnet is a distributed platform for illegal activities severely threaten the security of the Internet. Fortunately, although their complicated nature, bots leave some footprints during the C&C communication that have been utilized by security researchers to design detection mechanisms. Nevertheless, botnet designers are always trying to evade detection systems by leveraging the legitimate P2P protocol as C&C channel or even mimicking legitimate peer‐to‐peer (P2P) behavior. Consequently, detecting P2P botnet in the presence of normal P2P traffic is one of the most challenging issues in network security. However, the resilience of P2P botnet detection systems in the presence of normal P2P traffic is not investigated in most proposed schemes. In this paper, we focused on the footprint as the most essential part of a detection system and presented a taxonomy of footprints utilized in behavioral P2P botnet detection systems. Then, the resilience of mentioned footprints is analyzed using three evaluation scenarios. Our experimental and analytical investigations indicated that the most P2P botnet footprints are not resilient to the presence of legitimate P2P traffic and there is a pressing need to introduce more resilient footprints.     

Cytochemical characteristics of blast cells forming autologous rosettes in acute lymphoblastic leukemia in children

An increased content of cytochemically heterogeneous A-RFC (responses to acid phosphatase and acid nonspecific esterase) in peripheral blood of children with T-ALL in comparison with non-T, non-B-ALL has been established. No correlation between A-RFC content and T-cells bearing FcG- and FcM-receptors has been revealed. It is supposed that A-RFC is a heterogeneous group of T-cells differing in the stage of maturity.     

Use of monoclonal antibodies and lectins in the study of subpopulations of lymphoid cells in normal state and in leukemia

The heterogeneity of cell populations with peanut agglutinin receptors in reactive tonsilar tissue has been stated. It contains B lymphocytes (HLA-DR+, CD 10+, IPO-10+ cells), part of T-cells (CD 4+), but no CD 8+ lymphocytes. PNA+ CD 10+ cells are the normal analogues of centrocytic non-Hodgkin's lymphomas.