Chromosome painting as a supplement to cytogenetic banding analysis in non-Hodgkin's lymphoma.

Chromosomal in situ suppression (CISS) hybridization with biotin labeled chromosome-specific libraries was performed on short-term cultures from five cases of non-Hodgkin's lymphoma (NHL). The painting analysis proceeded in three stages. First-stage CISS hybridization was done with libraries specific for chromosomes that seemed to be lost or rearranged as judged by banding analysis. Second-stage CISS included hybridization with probes specific for chromosomes that, because of banding pattern similarities, were considered to be likely candidates to have contributed unidentified chromatin blocks in the abnormal karyotype. The third and final stage was a confirmation hybridization with a library specific for the chromosome that, at the stage two analysis, was found to have donated the previously unknown chromosomal segment. The aberrant chromosomes were often more complex than the banding analysis had led us to believe. Among the rearrangements whose nature was determined by CISS hybridization were two add(1)(p36) which, in both cases, were shown to be a der(1)t(1;2)(p36;q31). This study illustrates the potential use of chromosome painting in resolving karyotypic uncertainties in NHL, and it shows that new cytogenetic subgroups may emerge when classical banding analysis is supplemented with fluorescence in situ hybridization techniques.

Estimation of granulocyte and lymphocyte potassium in normal subjects and in patients treated with diuretics because of cardiovascular disease: a methodological study.

A method is described for measuring the potassium content in leukocytes using Percoll (R) density gradient centrifugation. Ninety subjects between 21 and 92 years formed the reference population. The magnesium content in leukocytes could not be estimated because of interaction between the ion and the Percoll (R) media. Sex, age, leukocytosis because of infection, physical stress, venous stasis did not interfere with the analysis. The potassium content was calculated per cell and per g-1 of DNA. The granulocyte potassium content was (median (range)) 37.4 (25.8-75.0) fmol/cell-1 or 2.9 (1.5-9.8) mmol g-1 DNA. The lymphocyte potassium content was 45.9 (26.4-69.6) fmol cell-1 or 3.3 (1.5-5.0) mmol g-1 DNA. The coefficient of variation (less than 10%) was not reduced by using cell DNA instead of cell number as reference. The interindividual variation was high, making the test unfit for clinical use. The leukocyte potassium content was not decreased in patients with acute myocardial infarction nor in patients treated with diuretics and potassium supplements because of cardiovascular disease.