Leukemia is a neoplastic proliferation of hematopoietic cells. Leukemia can be classified as either myelocytic (myeloid) or lymphocytic (lymphoid) depending on the lineage of the leukemic cells. Leukemia can also be either chronic or acute, depending on the clinical course and on the predominant maturational stage of the malignant clone. In this article, we will focus our discussion on acute myelocytic (myeloid) leukemia (AML), the most common acute leukemia found in adults.

Until recently, the leukemias have been classified using a system proposed by the French-American-British (FAB) Cooperative Group. Under this system, eight subgroups (M0 to M7) have been defined for AML and three subgroups have been designated for the acute lympho-cytic leukemias (ALL). This classification also includes the myelodysplastic syndromes (MDS) and the myeloproliferative diseases (MPD). The former category includes the following five subgroups: refractory anemia (RA), refractory anemia with ringed sideroblasts (RARS), refractory anemia with excess blasts (RAEB), refractory anemia with excess blasts in transformation (RAEBT), and chronic myelomonocytic leukemia (CMMoL). The MPDs include chronic myelogenous leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis with myeloid metaplasia (MMM). The above classification was established on the basis of morphological, cytochemical, and immunological parameters. Several of the above disease entities are more or less associated with specific chromosomal rearrangements, selected examples of which are given in Fig. 1, courtesy of Dr. J. Anastasi.

Although the FAB system has served as the gold standard for classification of malignant hematological diseases for a number of years, cancer centers are increasingly adopting the system proposed by the World Health Organization (WHO), as further discussed below.

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Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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