Shift from Rh-positive to Rh-negative phenotype caused by a somatic mutation within the RHD gene in a patient with chronic myelocytic leukaemia.

We report a female patient whose Rh phenotype shifted from RhD-positive to RhD-negative over a 3-year period (1991-94), during which time she was treated with mastectomy (1992) and local irradiation for a low-grade recurrent breast cancer. She was diagnosed with chronic myeloid leukaemia in 1994, and has since then received chemotherapy. The patient was repeatedly typed as O, RhD-positive between 1965 and 1991 and was repeatedly found RhD-negative after 1994. Bcr-Abl transcripts typical of Ph1 chromosome were detected. Molecular analysis indicated that the patient was heterozygous at the RH locus, carrying one haplotype in which the RHD gene exhibited a single nucleotide deletion (G600) resulting in a frameshift and premature stop codon, and a normal RHCE gene (allele Ce). The second haplotype contained only the RHCE gene (allele ce) and was normal. Further analysis carried out on total leucocytes, purified neutrophils, EBV-lymphoblastoid cell line and cultured erythroblasts indicated that the G600 deletion was restricted to the myeloid lineage. No modification of other blood group antigens could be detected. These findings suggest a somatic mutation which most probably occurred in a stem cell common to the myeloid lineage.

Temperature acclimation and oxygen binding properties of blood of the European eel, Anguilla anguilla.

Temperature acclimation of the European eel, Anguilla anguilla, resulted in red cell GTP/Hb molar ratios of 1.20, 1.77 and 0.80 at 2, 17 and 29 degrees C, respectively. A small increase in blood oxygen capacity was present in 29 degrees C acclimated eels. The CO2 Bohr effect and the shape of the oxygen binding curve (n-Hill) were invariant with both temperature and GTP/Hb. The significant differences in the GTP/Hb ratio corresponded with a strong enhancement of the temperature effect on blood oxygen affinity between 2 and 17 degrees C and a similarly strong compensation between 17 and 29 degrees C. Predicted in vivo P50 values were 3.0, 13.8 and 17.6 mmHg at 2 degrees C, 17 and 29 degrees C, respectively. The adaptational value of these findings are discussed in relation to standard metabolic rates at the various temperatures. A tentative hypothesis is proposed that the present study confirms and expands earlier work and supports the contention that adjustments in blood oxygen affinity of thermally acclimated teleosts serve to provide them with an unloading O2 tension for diffusion closely matching the standard oxygen requirements at the various temperatures.

Seasonal variations in hematocrit, red cell hemoglobin and nucleoside triphosphate concentrations, in the European eel Anguilla anguilla.

Eels acclimatized in nature show a significant annual variation in erythrocytic guanosine triphosphate (GTP) concentration, temperature range 0.5-17 degrees C. A similar but smaller annual variation is also present in eels acclimated in the laboratory at constant temperature, 17 degrees C. Hematocrit and blood oxygen capacity showed no seasonal variation. Natural minimal and maximal red cell GTP concentrations were found at the end of the dormancy period (March) and in the late summer, respectively. Furthermore, a chronological connection of the erythrocytic GTP values versus ambient temperature, in the natural environment, demonstrates a hysteresis. This allows for a prediction of a slowly progressing enhancement of the temperature effect on Hb-O2 binding throughout autumn, whereas a relatively fast and pronounced enhancement predictably takes place in spring (April-May) coincident with the "awakening" of the eels.