Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma

Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study.     

Ciliated respiratory-like epithelium forming cystic conjunctival lesions in a patient with Stevens-Johnson syndrome.

A woman with severe cicatricial conjunctival changes secondary to allopurinol-induced Stevens-Johnson syndrome developed bilateral palpebral conjunctival cysts. Pathologic examination of these lesions revealed respiratory-like pseudostratified ciliated epithelium in the walls of several cysts of one eye. To our knowledge, this is the first report of this phenomenon.     

Adrenocorticotropin receptors: functional expression from rat adrenal mRNA in Xenopus laevis oocytes.

The adrenocorticotropin (ACTH) receptor, which binds corticotropin and stimulates adenylate cyclase and steroidogenesis in adrenocortical cells, was expressed in Xenopus laevis oocytes microinjected with rat adrenal poly(A)+ RNA. Expression of the ACTH receptor in individual stage 5 and 6 oocytes was monitored by radioimmunoassay of ligand-stimulated cAMP production. Injection of 5-40 ng of adrenal mRNA caused dose-dependent increases in ACTH-responsive cAMP production. These were detected at 48 h and reached a maximum 72 h after microinjection of 20-40 ng of adrenal mRNA. In response to 1 microM ACTH, total cAMP production increased within 2.5 min and reached half-maximal and maximal levels (5-fold greater than basal) at 10 and 75 min, respectively, and then remained elevated for up to 5 h. Extracellular cAMP levels were much lower but showed prominent linear increases from almost undetectable levels, with 70- and 150-fold increases evident at 1 and 2 h, respectively. The half-maximal concentration (ED50) for stimulation of cAMP formation was 5 x 10(-8) M ACTH-(1-24); the ED50 for ACTH-(1-17) was 5 x 10(-7) M, and no response was observed with ACTH-(1-10). Size fractionation of rat adrenal poly(A)+ RNA by sucrose density-gradient centrifugation revealed that mRNA encoding the ACTH receptor was present in the 1.1- to 2.0-kilobase fraction. These data indicate that ACTH receptors can be expressed from adrenal mRNA in Xenopus oocytes and are fully functional in terms of ligand specificity and signal generation. The extracellular cAMP response to ACTH is a sensitive and convenient index of receptor expression. This system should permit more complete characterization and expression cloning of the ACTH receptor.