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).     

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.     

Initial morphological manifestations in experimental neuroleukemia

The results of the study of primary morphological manifestation of neuroleukemia (MMN) by mice with transplanting leukemia strains L 1210, P-388, L 5178Y, and are presented. It is determined that the MMN development degree depends on the leukemia cells dissemination amplitude after their transplantation and, in particular, on the degree of the bone-marrow affection, from which the leukemia cells grow into the dura mater encephali and epidural fat of the vertebral canal from the side of skull bones and vertebral canal. The analogous dependence is assumed to be present in a man and, therefore, there appears the possibility of using it for the neuroleukemia development frequency prognosing.     

ALA-PDT在耐药白血病细胞株HL-60/ADR中的实验研究

目的:本研究观察5-氨基乙酰丙酸介导的光动力疗法(ALA-PDT)对耐药白血病细胞株HL-60/ADR的诱导凋亡作用.方法:以耐药白血病细胞株HL-60/ADR为实验模型.实验分为4组,对照组、单纯ALA组、单纯光照组及ALA PDT组.用MTT法检测细胞的存活率,瑞特染色观察细胞形态学改变,用双染法检测细胞凋亡率,并用共聚焦激光显微镜观察凋亡细胞的特征.结果:ALA PDT组光照后瑞特染色可见凋亡改变;MTT法显示细胞存活率明显下降,24h为(48.67±8.14)%,48h进一步降低至(22.23±6.07)%,两者比较差异有统计学意义;流式细胞仪检测显示细胞凋亡率3h、4h和24h分别为(6.35±1.40)%、(8.07±1.87)%和(57.66±7.55)%,与对照组相比差异有统计学意义;LSCM观察AnnexinV-FITC单阳性及AnnexinV-FITC/PI双阳性细胞均具有典型的凋亡特征,而单纯ALA组、单纯光照组及对照组则无上述改变.结论:ALA-PDT能灭活耐药白血病细胞株HL-60/ADR,主要通过诱导凋亡的方式实现的,并呈一定的时间依赖性.     

Quantitative evaluation of the surface membrane receptors of leukemic cells to blood serum transcobalamin-II

Serum protein transcobalamin II (TC-II) is responsible for transport of cobalamins into mammalian cells. A method of quantitative estimation of plasma membrane receptors of hemopoietic cells to TC-II cobalamin complex is suggested. Analysis of mouse leukemia L1210 cells includes the saturation of radiolabelled ligand-receptor complex with papain. The number of receptors and 57CoCNCbl content in one cell is determined by differentiated radioactivity count of solubilized protein complexes and of cytoplasm.     

Hemopoietic precursor cells during the development of carminomycin resistance

A comparative quantitative investigation of colony-forming ability of mouse bone marrow hemopoietic stem cells in the case of ordinary leukemia variant (P-388) and carminomycin-resistant variant (P-388/k) was carried out. Leukemia bearing mice received single injections of increasing doses of carminomycin on the 5th day after transplantation and 24 hours later the bone marrow was investigated for quantity of colony-forming units in the spleen (CFUs). Dynamics investigation of bone marrow cells in the case of P-388 and P-388/k (without treatment) reveals the common tendency to a decrease of these cells in the period before animal death. Sensitivity of colony forming cells (CFUs) to different doses of the antibiotic of mouse bone marrow in both cases (P-388 and P-388/k) was practically the same. Dynamics of CFUs in two populations of cells after a single injection of carminomycin in doses causing the killing of 50% of CFUs showed that the antibiotic inhibited CFUs equally (50%). However this inhibition in case of CFUs with P-388/k leukemia was almost five times longer than in the case of ordinary P-388 one. Based on the investigations conducted the second injection of the antibiotic to mice with P-388/k leukemia on the fifteenth day after the first one may be recommended.     

Dynamic snap-back induced programming failure in stacked gate flashEEPROM cells and efficient remedying technique

A new kind of programming failure is reported in stacked gate Flash EEPROM cells and its remedying scheme is presented. The failure is observed under typical bit line (B/L) disturbance bias conditions but is different from the case of the drain turn-on induced leakage current over-burdening the charge pumping. Rather, its root cause is identified for the first time to be the dynamic snap back breakdown operative in the memory cell. This snap-back induced programming failure is shown effectively mitigated with the use of an appropriate series resistance in the source loop of the memory cell. The remedying role of the source series resistance is discussed     

Natural killer activity of splenocytes of C3HA mice in the early period after transplantation of hepatoma 22a cells

It is shown that during 10 days after transplantation of syngenic 22a hepatoma cells to C3HA mice, wave-like fluctuations of the natural killer cell (NK) activity of splenocytes take place. Xenogenic (K-562) and allogenic (AC-1) cells are used as target cells in the 18th hour 3H-uridine cytotoxic test. A significant increase in the NK-activity on the 2nd-3rd and 7-9th days after tumour cells transplantation is observed. Elimination of adherent cells from suspension of splenocytes lead to an increase in the NK-activity especially on the 7th-9th days.     

Evaluation of leukemogenic and immunogenic properties of leukemic cells modified by neuraminidase of non-cholera Vibrios on the model of Rauscher leukemia

The leukemogenic activity of modified leukemic cells was studied in experiments on the 385 BALB/c mice with Rauscher leukemia by transplantation of different amount of treated cells. Immunogenicity of modified leukemic cells was estimated under conditions of three-fold immunization of animals 2 days later by the cells dose equal to 1.10(6) which began 24 h after the leukemia transplantation. The effect of immunotherapy of neuraminidase-modified leukemic cells results in elongation of animal lifetime, presence of less pronounced changes in the peripheral blood and spleen as well as in stimulation of cell immunity factors.     

Colony-forming ability of bone marrow hematopoietic cells in mice with transplanted leukemia during administration of carminomycin

Effects of carminomycin on the colony-forming ability of bone marrow haemopoietic stem cells (CFUs) were compared in normal mice with steady state and actively regenerating bone marrow, and in P-388 and La leukemia-bearing mice. CFUs assays were performed 24 h after treatment of donor mice with the increasing doses of the drug. Leukemia-bearing mice received carminomycin on the 5th day after transplantation. The dose-effect curves were exponential for CFUS normal mice with both the steady state and active proliferation state of bone marrow. The maximal effect was found 24 h after injection of 0.7 mg/kg of carminomycin (ED50 for CFUS) being more pronounced in regenerating bone marrow. The dose-effect curves for leukemias were also exponential. In the case of La leukemia the killing of CFUs by carminomycin was the highest as compared with P-388 leukemia.     

Normalization of the phenotype of transformed Djungarian hamster cells during selection for colchicine resistance

The range of the Djungarian hamster cell lines selected for colchicine resistance in high doses (from 7 to 200 micrograms/ml) was studied. These cell lines are characterized by the different levels of drug-resistance (1000- to 16000-fold). A positive correlation is found between the reversion rate of malignant phenotype and the cellular drug-resistance level. Tumorigenicity and anchorage independence decrease with an increase of the drug-resistance level. The actin-containing bundles of microfilaments in more resistant cells are more organized. The 22 kD protein content increases with the drug-resistance level. The mechanisms of malignancy reversion are discussed.     

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.     

Enhanced antitumor action of 5-fluorouracil when used in combination with 4-methylmercaptopyrazolo[3,4-d]pyrimidine 1-nucleoside

Mice BDF1 with L 1210 or mice BALB/c with plasmacytoma MOPS-406 after pretreatment with ineffective doses of 1-beta-D-ribofuranosyl-4-methylmercaptopyrazolo(3,4-d)pyramidin e (25 to 100 mg/kg per 5 days) were treated with 5-fluorouracil at the optimal dose 100 mg per day. This combination produced a 1.5-2-fold or 2 to 4 fold enhancement of the antitumour effect of 5-fluorouracil without simultaneous increase of lethal toxicity.     

痰热清注射液对慢性髓系白血病K562细胞增殖的抑制作用

目的观察痰热清注射液对慢性髓系白血病K562细胞增殖的抑制作用。方法将痰热清注射液倍比稀释成1:2、1:4、1:8、1:16、1:32、1:64、1:128、1:256、1:512共9个浓度组,分别处理增殖期慢性髓系白血病K562细胞,镜下观察不同时间点各浓度组细胞生长情况,应用CCK-8法检测细胞增殖能力,绘制生长曲线,计算抑制率和半数抑制浓度(IC50)。结果痰热清注射液能明显抑制K562细胞增殖,细胞倍增时间为24h,1:2至1:8稀释浓度组的细胞毒性大,细胞基本死亡;抑制作用呈剂量和时间依赖性,IC50约为1:55稀释浓度。结论痰热清注射液对K562细胞具有抑制作用,这为临床应用痰热清注射液治疗血液肿瘤并发感染提供了实验基础。     

Cytological characteristics of carminomycin-resistant P-388 lymphoid leukosis

The carminomycin-resistant strain (P-388/c) of P-388 lymphoid leukemia is obtained. Resistance development is accompanied by higher sensitivity to cytostatics, rise of hyperploidy, replacement of the stem line, presence of definite markers in leukemic cells as well as by the appearance of a clone of cells with higher dry mass. At the level of CFUs after the carminomycin administration more remote terms of cell restoration than in case of P-388/c lymphoid leukemia are determined. The P-388/c lymphoid leukemia cells lost their sensitivity to carminomycin at the stage of the DNA synthesis. Accumulation of cells is observed in phase G2 of the mitotic cycle.     

单倍型异基因造血干细胞-脐带间充质干细胞联合移植治疗1例急性白血病

目的研究急性粒细胞白血病异基因造血干细胞-人脐带源间充质干细胞（hUG—MSC）联合移植效果。方法急性髓性白血病-M2,供者为其胞兄,HLA单倍型相合,移植物为经粒细胞集落刺激因子（Granulocyte Clony—Stimulating Factor,G—CSF）动员的骨髓以及外周血造血干细胞,加入分离、扩增的hUC—MSC。移植物抗宿主病（Graft—Versus—Host Disease,GVHD）预防采用环孢菌素A＋ATG^＋霉酚酸酯＋短程甲氨喋呤和CD25单抗。结果输注供者的MSC总数和CD34细胞数分别为7．92×10^8/L和3．78×10^6／L。中性粒细胞大于0．5×10^9／L和血小板大于20×10^9／L的时间分别为14d和15d。24d嵌合体100％,40d左右出现Ⅰ度aGVHD,治疗后好转,未出现其他严重并发症。结论异基因造血干细胞-人脐带源间充质干细胞（hUC—MSC）联合移植安全简便,可加速造血功能恢复。     

人急性粒细胞白血病细胞的无丝分裂现象

用电子显微镜观察了8例急性粒细胞白血病的外周血标本。结果发现在2例标本中存在白血病细胞的无丝分裂现象。无丝分裂过程先是细胞核中部缢缩形成哑玲状细胞核，然后分裂成两个子细胞核，最后细胞一分为二、完成细胞分裂。在这一过程中核膜不消失，不形成染色体。由于目前对白血病的治疗是以白血病细胞的动力学规律为基础的，没有考虑到白血病细胞无丝分裂的因素，因此白血病细胞的无丝分裂现象可能是化疗后残存白血病细胞的原因之一。     

Role of intracellular pH in the development of resistance of leukemic cells to antineoplastic drugs

Intracellular pH (pHi) of mouse lymphoid leukemia P388 cells was measured at the wavelength of 518 and 570 nm of fluorescein: pHi of rubomycin-sensitive P388 cells was higher than pHi of the cells resistant to this antitumour antibiotic (6.98 +/- 0.04 and 6.63 +/- 0.03, respectively, P less than 0.001). The role of pHi is established during induction of the resistance of tumour cells to the antitumour drugs.     

Dynamics of the chromosomal damages to Ehrlich ascitic cancer and bone marrow cells of mice by the antitumor preparation dimetinur

The dimetinur effect upon chromosomes of the Ehrlich ascite carcinoma and bone marrow cell populations was analyzed by the cytogenetic method for 10 days after i.p. and i. v. drug administration in doses from 50 to 150 mg/kg. Kinetic regularities of changes in a fraction of cells with chromosome breakages and in the number of broken chromosomes per cell as well as "dose-effect" relations are determined. A linear correlation is established between the level of residual chromosome damages in a population of tumour cells and the coefficient of activity chi* characterizing the antitumour effect of dimetinur. Selectivity of the dimetinur mutagenic action expressed as a more deep and prolonged damage of the genetic system of tumour cells as compared to bone marrow cells of tumour-bearing animals is shown under conditions of a pronounced therapeutic activity.     

Phosphorus-containing metabolites in the cells of anthracycline-resistant strains of leukemia P388

The method of 31P nuclear magnetic resonance has been used to study in vivo the level of phosphorus-containing metabolites in cells of two strains of murine leukemia P388 with the phenotype of the multidrug resistance and in cells of the parent strain. Cells of both resistant strains showed a depressed level of phosphomonoesters in comparison with the parent one. The influence of rubomycin and emoksil on the level of phosphorus-containing metabolites of drug-resistant and -sensitive strains has been evaluated. The drugs were established not to affect practically the pool of these metabolites of the resistant strains. Both drugs significantly increased the pool of phosphomonoesters in the parent strain cells.