Cell production and cell function in human cyclic neutropenia

In vitro studies have been done on haematopoietic cells from a patient with cyclic neutropenia characterized by severe depression of blood neutrophil levels every 21 days. Serial blood counts reveal periodic fluctuations in neutrophils, monocytes and reticulocytes. Agar culture of marrow cells shows normal concentration of colony forming cells. The percentage of colony forming cells in S phase is highly increased during profound neutropenia and normal during the recovery phase relating the granulocyte production to the peripheral neutrophil level. Studies of ingestion rate, bactericidal activity, lactate production and glucose oxidation during phagocytosis in isolated granulocytes show normal results. Also the ingestion rate in isolated monocytes is normal. Serial karyotype analyses of marrow cells during the neutrophil cycle display a normal pattern. Serum myeloperoxidase levels vary inversely with the peripheral neutrophil count indicating increased granulopoietic activity during profound neutropenia, which might be associated with non effective granulopoiesis during profound neutropenia, leading to a lack of granulocyte reserves in the marrow.

Chromosome abnormalities identified by banding technique in a patient with acute myeloid leukaemia complicating Hodgkin's disease

Chromosome analyses using the Giemsa banding technique were performed on bone marrow cells in a patient with the association of Hodgkin's disease and acute myeloid leukaemia. All cells had an abnormal karyotype showing an extra chromosome No. 14, loss of one chromosome No. 17 and gain of one chromosome No. 18. These abnormalities are in many respects similar to the karyotype changes of lymphoid cells in malignant lymphomas, suggesting a pathogenetic relationship between the two disorders.

Isochromosome 17 in a case of eosinophilic leukaemia. An abnormality common to eosinophilic and neutrophilic cells

In a patient with eosinophilic leukaemia, serial chromosome studies using the Giemsa banding technique revealed a similar marker chromosome, identified as an isochromosome 17, in all bone marrow metaphases analysed. There was no Ph-1-chromosome. The cytogenetic data support the view that eosinophilic leukaemia is a specific disease entity, and suggest that both eosinophilic and neutrophilic cells are involved in the leukaemic process.

Megaloblastic changes and chromosome abnormalities of erythropoietic cells in acute myeloid leukaemia

Using Giemsa banding technique, the bone marrow chromosomes were studied in 9 patients with acute myeloid leukaemia (AML). Four patients had 100% normal diploid cells and 5 had 100% abnormal cells: 28-92% of the mitoses were found in erythroid cells. The percentage of erythroblasts with megaloblastoid changes was abnormally high. It was not increased in the cases with chromosomal abnormalities. These findings indicate that chromosomal aberrations are not prerequisites for the development of megaloblasts in AML. Furthermore, abnormalities in the DNA synthesis bringing about the megaloblastoid changes may occur without influencing karyotype.

Tumor etiology and chromosome pattern

Fibrosarcomas induced in Chinese hamsters and rats by Rous sarcomla virus and 7,12-dimethylbenz(a)anthracene are associated with nonrandom chromosome variation. Although histologically indistinguishable, the tumors induced by the virus or chemical in each host species are characterized by completely different karyotypic patterns.