Proliferation and maturation of human erythroid progenitors in liquid culture

Hemopoiesis is studied in vitro mainly in semisolid culture, where hemopoietic progenitors develop into discrete colonies. We describe a liquid culture system that supports the proliferation and maturation of human erythroid progenitors. We seeded mononuclear cells from the peripheral blood (PB) of patients with beta-thalassemia in liquid medium in the presence of conditioned medium from human bladder carcinoma cells. Seven days later, RBCs, normoblasts, granulocytes, and monocytes disappeared, and the number of lymphocytes dropped considerably. In contrast, erythroid colony-forming cells increased fourfold to tenfold. The next step entailed the removal of colony- stimulating factor (CSF) and CSF-secreting cells, the exclusion of macrophages by harvesting nonadherent cells, and the lysis of T lymphocytes by treatment with monoclonal rat antihuman lymphocyte antibodies (CAMPATH-1) and complement. Reculture of the remaining cells in liquid medium supplemented with recombinant erythropoietin (EPO) resulted in the exclusive development of erythroid cells, with myeloid cells reduced to less than 2%. Stainable hemoglobin (Hb) appeared on day 3, with over 85% of the population containing hemoglobin by day 11 and the cell number increasing from 0.2 X 10(6) to 3 X 10(6) mL. By permitting the manipulation of culture conditions and components and increasing the cell yield, the liquid system may facilitate quantitative analysis of growth kinetics as well as biochemical and immunologic characterization of the developing erythroid cell.     

Microsatellite instability and p53 mutations in therapy-related leukemia suggest mutator phenotype

During the last decade the frequency of therapy-related acute leukemia (t-leuk) and myelodysplastic syndrome (t-MDS) has been increasingly observed. Over the past 15 years, we treated 56 patients with t-leuk who had received prior chemotherapy (39%), radiotherapy (11%), or both (45%). The drugs received included alkylating agents and topoisomerase II inhibitors. The primary tumors included hematological malignancies (49%) and solid tumors such as breast or ovarian cancer. The median age at diagnosis of the primary tumor was relatively young (43 years +/- 18). Twelve patients had more than one primary tumor and 31 patients had a family history of malignancy. Karyotypic abnormalities were found in 91% of the patients. Prognosis was uniformly poor, with an overall median survival of 10 months. Twelve of the 18 patients examined (67%) had a multidrug resistance phenotype. P53 genes of the leukemic cells, as well as the original tumors, were analyzed in 21 patients using polymerase chain reaction (PCR) with single-stranded conformation polymorphism analysis followed by sequencing. P53 mutations were identified in 38% of these patients, a relatively high prevalence compared with other forms of MDS or de novo acute myeloid leukemia. Mutations were nongermline and restricted to the leukemic cells. We identified different p53 mutations in the various primary tumors of individual patients. The presence of a mutator phenotype was assessed by PCR analysis of microsatellites in eight loci (one trinucleotide repeat sequence, four dinucleotide, and three mononuclear repeat sequences). Microsatellite instability in two to seven loci were found in 15 of 16 (94%) of the patients. This instability is compatible with a mutator phenotype, which predisposes the patients to the development of malignancies including t-leuk.     

成像检查对腰背痛治疗临床决策的影响

目的 :评价断面成像 ,如磁共振成像 (ＭＲＩ)、计算机体层成像 (ＣＴ)对腰背痛 (ＬＢＰ)患者的临床决策的影响。方法 :对 14 5例有症状的腰椎疾病且曾就诊过神经外科或骨科医生的患者进行前后随机对照研究。参与者是腰背痛 (ＬＢＰ)治疗中两种成像检查的多中心实用随机比较的亚群 :即“成像”对“未成像” ,除非出现明确的指征。配对的评价是由诊断、诊断可信度、后续治疗、试验开始和随访的治疗可信度以及预期的成像所组成。数据通过随机组分析得到。结果 :在随访中有关诊断和治疗方案组之间并无统计学显著差异。但在两组中诊断和治疗可信…     

A new cephalic reference plane for use with magnetic resonance imaging: the chiasmato-commissural plane

Summary A cephalic reference plane is described through the chiasmatic notch and the posterior commissure, which is easily identified on mid-sagittal cuts using magnetic resonance imaging. The horizontal cuts so obtained are almost parallel to the lateral fissure and are perpendicular to the axis of the brain stem.This work was published in part in C R Acad Sci Paris, t. 311, série III, p. 115–121, 1990