Mitochondrial sequence variation suggests an African influence in Portuguese cattle.

A total of 49 samples from indigenous Portuguese cattle breeds were analysed for sequence variation in the hypervariable region of the mitochondrial DNA D-loop. Sequence comparison and phylogenetic analyses revealed that haplotypes fell into two distinct groups. These corresponded with two separate haplotype clusters into which, respectively, all African, or alternatively all sequences of European origin, have previously been shown to fall. Here, the majority of sequences of African type were encountered in three southern, as compared to three northern breeds. This pattern of African influence may reflect an intercontinental admixture in the initial origins of Iberian breeds, or it is perhaps an introgression dating from the long and influential Moorish occupation of the south of the Iberian peninsula.

Cytogenetic findings in a patient presenting simultaneously with chronic lymphocytic leukemia and acute myeloid leukemia.

A case of simultaneous presentation of B-chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML) is described. CLL was documented by bone marrow and peripheral blood lymphocytosis with a typical B-CLL immunophenotype. The diagnosis of AML was supported by the presence of bone marrow and circulating blast cells positive for myeloperoxidase and myeloid-associated markers. Although the immunophenotyping and morphocytochemical studies indicated two different cell populations (mature B-CLL lymphocytes and myeloblasts), chromosome aberrations commonly associated with CLL and AML were found simultaneously in the same metaphases obtained from unstimulated 24-hour cultures of peripheral blood cells.

[Cytogenetic studies in hematological diseases. Analysis of 185 cases]. / Estudios citogenéticos en enfermedades hematológicas. Análisis de 185 casos.

PURPOSE: To analyse the chromosomal abnormalities found at diagnosis in patients with malignant blood diseases. PATIENTS AND METHODS: Between june 1988 and january 1992, cytogenetic studies were performed at the Cytogenetics Laboratory of the Abel Salazar Institute for Biomedical Sciences on 185 patients with malignant blood diseases. Bone-marrow and/or peripheral blood cells were used for such studies, two simultaneous cultures being prepared at 24 and 48 hr, plus another one, stimulated with phytohemagglutinin, at 72 hr. Trypsin G-banding techniques were used for chromosome identification. Chromosomes were classified in accordance with the international system, and a clone was judged abnormal whenever two or more metaphases showed identical structural abnormalities or extra chromosome(s) and three or more metaphases lacked the same chromosome(s). RESULTS: Evaluable mitoses were found in 152 of the 185 cytogenetic studies performed (82.2%), pertaining to chronic myelogenous leukaemia (39/42), acute nonlymphoblastic leukaemia (40/43), myelodysplastic syndromes (10/17), acute lymphoblastic leukaemia (30/36), and chronic lymphoproliferative disorders (10/14). Chromosomal alterations, previously described in each diagnostic variety, were found in 69% of the cases with abnormal karyotype. The remaining patients (31%) had chromosomal abnormalities not reported consistently. CONCLUSIONS: The karyotype should be studied regularly in haematologic disorders since, although lacking precise prognostic implications, it may help gain information with regard to the genetic alterations in different blood diseases.