The karyotype of leukemic cells of 78 acute leukemia patients (37 ANLL, 34ALL, and 7 of unknown type) was studied by means of G-banding. Chromosomal abnormalities were found in 50 patients (72%). Chromosomes 8,21,5,7,11, and 19 were preferentially involved in the abnormalities, both in ANLL and in ALL. A high incidence of the characteristic rearrangement t(8;21) was noted in AML: (in 6 of 22 AMP patients). An identical reciprocal translocation--t(4;11)--was seen in 4 out of 34 ALL patients.

Banded chromosomes of leukemic cells were studied in 53 children with chronic myeloid leukemia (CML). Ph1 chromosome was found in 21 children, and the remaining 32 cases were Ph1 negative. Besides Ph1 translocation additional chromosomal abnormalities, including marker i(17q), were revealed in three of eight children studied in blastic crisis of Ph1 positive CML. Leukemic cells of most patients with Ph1 negative CML possessed normal karyotype. Clones with chromosomal abnormalities were found in 12 of 32 cases. Most characteristic were monosomy 7 (in four children) and trisomy 8 (in three). Abnormal karyotype may be a bad prognostic sign in Ph1 negative CML. The presented data confirm the difference in age of appearance, bone marrow pattern and clinical course between Ph1 positive ("adult") and Ph1 negative (juvenile) types of CML in children. Probable prenatal commencement of CML in babies and children in the first years of life is discussed.

No abstract

PCR is ubiquitous in molecular biology. It is used to amplify single sequences from large genomes, or populations of sequences from complex mixtures such as cDNA libraries in mammalian cells. These cDNA libraries are often employed in subsequent labor-intensive experiments such as genetic screens, the outcome of which depends on library quality. The use of PCR to amplify diverse sequence populations raises important technical issues. One question is whether or not PCR is capable of maintaining population diversity, specifically with respect to template selection in the first rounds of the amplification process (i.e., the possibility that rare sequences in a complex mixture are lost because of amplification failure at the outset of the PCR). Here, we analyze the properties of PCR in the context of template selection in complex mixtures and show that it is an excellent method for preserving diversity.

To date, only anti-glycophorin-A monoclonal antibodies (MAbs) have been widely used as anti-erythroid probes in the diagnosis of leukemias. We have examined blood, bone-marrow and lymph-node samples from 474 patients, adults and children, with different hemopoietic malignancies, using a panel of MAbs including 2 anti-erythroid MAbs directed to glycophorin-A and an antigen of erythroblasts, Ag-Eb. MAb HAE9 directed against a human epitope of Ag-Eb has earlier been shown to be highly specific for immature erythroid cells. Of all the patients, 2.7% demonstrated glycophorin-A expression on blast cells, while anti-Ag-Eb MAb HAE9 reacted positively with cells from 6.0% of patients. Samples from 31 of 474 (6.5%) patients expressed one or both erythroid markers. Our results indicate that MAb HAE9 may be useful, in combination with anti-glycophorin-A MAbs, as an anti-erythroid probe for immunophenotyping human leukemias.