Rearrangement and expression of T cell antigen receptor genes in B cell chronic lymphocytic leukemia.

Fifty-nine patients with B cell chronic lymphocytic leukemia (B-CLL) were screened for clonal rearrangement of T cell receptor (TCR) beta and gamma chain genes. Four were found with rearranged TCR beta genes, but none had detectable rearrangement of TCR gamma genes. One typical patient with B-CLL had a TCR beta gene structure consistent with a variable-diversity-joining rearrangement into the C beta 2 gene on one allele.

Patterns of gene expression during plasmacytoid differentiation of chronic lymphocytic leukaemia cells.

Chronic lymphocytic leukaemia (CLL) cells may be induced to undergo plasmacytoid differentiation in vitro in response to 12-O-tetradecanoyl phorbol acetate (TPA). We show here that plasmacytoid differentiation and the accompanying accumulation of Cmu immunoglobulin mRNA are preceded by a rapid transient increase in the expression of the proto-oncogenes, c-myc and c-fos. In terminally differentiated cells the level of c-fos mRNA returned to the original basal level whilst c-myc expression remained appreciably higher than in undifferentiated CLL cells.

Nocturnal high-dose dexamethasone suppression test in the aetiological diagnosis of Cushing's syndrome.

Seventeen patients with well-proven Cushing's syndrome (13 with Cushing's disease, 3 with adrenal tumour and 1 presenting ectopic ACTH syndrome caused by bronchial carcinoid) were investigated by using a single-dose 8 mg dexamethasone nocturnal test. The results obtained were compared with those of the classical 8 mg Liddle's test, metyrapone stimulation, plasma ACTH concentration and with the final diagnosis reached through surgery, pathologic anatomy, and/or clinical and biochemical follow-up of the patients after treatment. The diagnostic efficacy or the predictive power of the test (defined as the ratio between the number of cases in which the diagnosis was correctly predicted and the total number of cases), was at least 82.

Morphine analgesia and tolerance in the tail-flick and formalin tests: dose-response relationships.

The dose-response relationships for morphine analgesia were studied in morphine-tolerant and non-tolerant rats using two pain tests: the tail-flick test which measures the threshold for an escape response, and the formalin test which assesses the behavioral response to continuous pain generated in injured tissue. The effects of prior experience with both pain tests on tolerance were also examined. In the formalin test, effective analgesia was obtained in non-tolerant rats at doses that produce minimal depression of locomotor behavior.

Structure of plant nuclear and ribosomal DNA containing chromatin.

Digestion of plant chromatin from Brassica pekinensis and Matthiola incana with staphylococcus nuclease leads to a DNA repeat of 175 plus or minus 8 and a core size of 140 base pairs. DNase I digestion results in multiples of 10 bases. Ribosomal RNN genes were studied as a model system for active plant chromatin because of their great redundancy and their high transcriptional activity in growing and differentiating tissues.

Studies on the fate of homologous DNA applied to seedlings of Matthiola incana.

Seedlings of Matthiola incana (crucifer) are able to take up exogenous homologous DNA by the roots. DNA homogenously labelled with [3H]adenine and 5-bromodeoxyuridine is incorporated into the plants in a macromolecular form. Intact donor DNA and a fraction with a buoyant density intermediate between that of the donor and the recipient DNA can be recovered.