Purification and structural characterisation of human HLA-linked B-cell antigens.

The human B cell-specific alloantigen which is closely linked genetically to HLA contains two non-covalently associated, sialogycoprotein subunits of molecular weight (MW) 29,000 (p29), and 34,000 (p34). Although p29 and p34 have different amino-terminal sequences, their tyrosine peptide maps indicate considerable similarity in other portions of their polypeptide chains. Thus the genes for their proteins may have evolved by duplication of a common ancestral gene. Another lymphocyte cell surface protein of MW 16,000 (p16) has also been characterised. Both p16 and p44 (the heavy chain of HLA-A,B antigens) have been compared with p29 and p34.     

Nickel content of human lymphoblastoid cells cultured in a nickel sulfate-enriched medium]

Nickel is titrated by atomic absorption in nuclear and non-nuclear fractions of cells cultured in media supplemented by nickel sulphate. The living cell percentages are estimated in the same culture conditions. We try to connect the nickel presence in cellular fractions and the living cell percentages. These used cells seem to have mortality probability when nuclear fraction has 55 x 10(-6) of nickel and non-nuclear fraction has 33 x 10(-6) of nickel. We discuss the nickel stimulating effect for the start of DNA synthesis and the nickel penetration into cells.     

Radioimmune, radiobinding and HPLC analysis of 2-5A and related oligonucleotides from intact cells

The enzyme (2-5A synthetase) which synthesizes ppp(A2'p)nA where n=2 to 4 (collectively referred to as 2-5A) is widely distributed in a variety of cells and tissues in amounts which increase response to interferon and vary with growth and hormone status. 2-5A activates a nuclease which inhibits protein synthesis. The non-phosphorylated 'core' of 2-5A ((A2'p)nA, n=2 to 4) can inhibit DNA synthesis and cell growth. Here we describe convenient and sensitive radioimmune (RI) and radiobinding (RB) assays for core and 2-5A. In combination with more satisfactory high performance liquid chromatography (HPCL) methods using reverse-phase C18 columns, these assays have been used to detect core and 2-5A in crude extracts from interferon-treated cells. The novel 2-5A synthetase products NAD2'p5' A2'p5'A and A5'p45'A2'p5'A2'p5'A (ref. 13), which can also be detected using the RB assay, were not found in significant amounts. The natural occurrence of core has not been described previously.     

1,2-di-n-butylhydrazine dihydrochloride carcinogenesis in mice

Summary A solution of 0.0625% 1,2-di-n-butylhydrazine dihydrochloride (1,2-DBH) was given continuously in the drinking water of 6-week-old randomly bred albino Swiss mice for the remainder of their lives. The treatment gave rise to tumors of the lungs, lymphoreticular tissue and kidneys.     

Pressor and oxitocic-like effects of angiotensin affected by aldosterone pretreatment in guinea-pigs

Résumé Les auteurs examinent l'augmentation de l'action de l'angiotensine sur la pression carotidienne et sur la contraction utérine chez des animaux traités avec de l'aldostérone. Ils pensent aussi que le traitement conditionne le développement du phénomène taquiphylactique de l'angiotensine.     

Similar effects of arginine-vasopressin and arginine-vasotocin on permeability of toad skin

Résumé Des crapauds ont été employés pour doser l'action des peptides neurohypophysaires sur la perméabilité de la peau. L'arginine⁸-vasopressine et l'arginine⁸-vasotocine ont en absence de Na⁺ le même effet. Elles augmentent les mouvements de l'eau, à doses variées, et leur action à toutes deux est 2000 fois plus puissante que celle de l'oxytocine. En presence de Na⁺ l'action de l'arginine⁸-vasotocine est 3 fois plus grande que celle de l'arginine⁸-vasopressine. Elles sont respectivement 120 fois et 40 fois plus puissantes que l'oxytocine.