Globin Synthesis in Normal Human Bone Marrow

S ummary . Globin synthesis has been studied by in vitro labelling with radioactive amino acids in 60 normal human bone-marrow samples. Under the conditions routinely used to fractionate α and β chains by chromatography α/β production ratios ranging from 0.5 to 1.0 were obtained, depending on the method of sample treatment. This variation was due entirely to the presence of non-haem proteins derived from white cells which chromatograph with globin on CM-cellulose. Purification of globin on Sephadex G100 and fractionation of α and β globin chains by a modified chromatographic system resulted in α/β ratios of unity. The relevance of these findings to the study of marrows in which there is unbalanced globin chain production is discussed.     

Unrelated Allogeneic Bone Marrow Transplant in Adrenoleukodystrophy Using CD34+ Stem Cell Selection

Adrenoleukodystrophy is an inherited disease characterized by progressive neurodegeneration with rapid deterioration to a vegetative state. Of the treatment modalities tried to date, BMT is the only one with the potential for cure. However, the high rate of morbidity and mortality associated with allogeneic transplant makes it necessary to try out novel measures to improve the outcome in these patients. We report here a case where we used CD34⁺ stem cell selection for allogeneic unrelated-donor BMT in a patient with adrenoleukodystrophy.     

Separation of Normal Mature Bone Marrow Plasma Cells

S ummary A three-phase purification process for the separation of normal bone marrow plasma cells is described. Material was obtained from haematologically normal humans and baboons. Known monoclonal and polyclonal B cell activators were avoided both in vivo and in vitro. In Phase I, bone marrow fragments were separated from cell suspensions by buoyant density methods. Marrow fragments were shown to be richer in plasma cells than the corresponding marrow cell suspensions. Phase II consisted of culturing fragments by a simple suspension method in which a selective affinity of plasma cells and marrow stromal cells resulted in further concentration of plasma cells with discharge of haemopoietic elements. Maximum concentration of plasma cells occurred within 7 d. In phase III, fragments were disaggregated with trypsin, and the marrow stromal cells were removed by their adherence properties. The resulting non-adherent fraction comprised approximately 85% plasma cells. The process allows for direct quantitative evaluation of normal plasma cell physiology in vitro.     

Thymidine Kinase Activity in Human Bone Marrow Cells

The thymidine kinase activity per 10⁶ DNA-synthesising marrow cells and the rate of incorporation of tritiated thymidine into the DNA of 10³ DNA-synthesising marrow cells were estimated in 9 haematologically normal patients and 49 patients suffering from a variety of haematological disorders. Slight increases in thymidine kinase activity were found in 6 of the 31 patients with haematological diseases associated with normoblastic erythropoiesis and greater increases were found in 3 of the 18 patients with megaloblastic haemopoiesis due to vitamin B₁₂ or folate deficiency. In the latter group, there was a statistically significant inverse correlation between haemoglobin levels and thymidine kinase activity. No correlation was found between thymidine kinase activity and the rate of incorporation of tritiated thymidine in either the normoblastic or megaloblastic group, suggesting that the level of thymidine kinase activity does not limit the rate of incorporation of exogenously supplied thymidine into the DNA of human bone marrow cells.     

Separation of Human Bone Marrow Cells by Sedimentation

Sedimentation at unit gravity of human bone marrow cells, for 15 h at 4° C on a linear density gradient of Ficoll in culture medium ranging from 1.020 to 1.065 g/ml shows that a differential migration of the bone marrow cell sub-populations exists with precise mean densities 1.021 ±lx 10^?3 g/ml for lymphocytes; 1.024 ± 2.5 times 10^?3 g/ml for non-eosinophil granulocytes; 1.025 ± 2.5 times 10^?3 g/ml for metamyelocytes; 1.030 ± 3.5 times 10^?3 g/ml for other myeloid cells (myeloblasts, promyelocytes, myelocytes); 1.040 ± 3 times 10^?3 g/ml for eosinophil granulocytes; and 1.055 ± 10 times 10^?3 g/ml for megakaryocytes. The highest percentages of S phase cell and G2 and M phase cells determined by a cytofluorograph correspond to the peaks of immature myeloid cells (myeloblasts, promyelocytes and myelocytes). This method of bone marrow cell separation may be used to study the cell cycle in pathological bone marrows (leukaemia in particular) and to determine the effects and the efficiency of some antimitotics.     

CD5+ Diffuse Large B-Cell Lymphoma Consists of Germline Cases and Hypermutated Cases in the Immunoglobulin Heavy Chain Gene Variable Region

CD5+ diffuse large B-cell lymphoma (DLBCL) has recently been identified as a subgroup with different clinical characteristics from CD5- DLBCL and as having a poorer outcome than CD5- DLBCL. Data regarding differences in gene alteration between CD5+ and CD5- DLBCL have accumulated. In this article, we report an analysis of the immunoglobulin heavy-chain gene variable region (VH) gene in 35 cases of CD5+ DLBCL and compare these cases with those with the germline of the VH gene (GL-VH) and those with a somatically hypermutated VH gene (HM-VH). When the CD5+ DLBCL cases were subdivided with a cutoff value of 98% homology in the VH gene, there were 7 cases (20%) of GL-VH and 28 cases (80%) of HM-VH. The proportion of GL-VH cases in CD5+ DLBCL was more than that in CD5 DLBCL. Although we found no significant difference in pretreatment clinical parameters between the GL-VH and HM-VH subgroups, there was a tendency for the GL-VH subgroup to show lower incidences of elevation of lactate dehydrogenase and >1 site of extranodal involvement compared to the HM-VH subgroup. The overall survival curve of the HM-VH subgroup showed a rapid decline followed by a plateau, whereas that of the GL-VH subgroup declined constantly after 5 years, suggesting that GL-VH disease may not be curable by standard therapies. These findings suggest that CD5+ DLBCL with GL-VH shares clinical features with mantle cell lymphoma, the cellular origin of which has been considered to be pre-germinal center B-cells. We therefore propose that analysis of the VH gene is important for predicting the clinical course of CD5+ DLBCL.