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Biomedical subjects

G Dietz

Publications and source records attributed to G Dietz.

At least 55 records · Page 3Linked to original sources
PubMed1986

Enzymes of purine metabolism in hairy cell leukemia.

Differences in activities of the purine degradative enzymes, adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and 5'-nucleotidase (5'NT), have been observed among different classes of lymphoid malignancies. Recent studies have shown that hairy cell leukemia (HCL) may respond to treatment with the ADA inhibitor, 2-deoxycoformycin. This study demonstrates that the cells of HCL have significantly lower levels of ADA and 5'NT (P always less than 0.01) when compared to levels in normal B- or T-lymphocytes, but have higher levels of PNP (P less than 0.001 for both comparisons). Recent studies have shown that when treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), cells of B-cell chronic lymphatic leukemia (B-CLL) acquire phenotypic characters of HCL. The authors have therefore also investigated the changes in enzyme pattern of B-CLL after incubation with TPA B-CLL cells are characterized by low levels of ADA, PNP, and 5'-NT, but TPA caused a marked increase in PNP activity (P less than 0.001, t test for paired samples), a pattern similar to HCL. The results from biochemical studies are thus in accordance with the hypothesis that HCL cells are more mature than B-CLL cells. The special enzyme profile of HCL suggests that a PNP inhibitor might also be effective in the treatment of this disease.

5'-Nucleotidase↗
PubMed1986

[A hitherto unknown reaction pattern in vertebrate cells (RiV). 2. The protective effect of RiV particle preparations against foot-and-mouth disease in guinea pigs].

Further observations concerning the previously described RiV-particles are reported. They were isolated from a diploid cell line of bovine origin, embryonal duck fibroblasts and BHK-21 cells. A protective effect against foot-and-mouth-disease virus in guinea pigs could be observed following inoculation with the RiV-preparation of bovine origin. All 3 preparations isolated from the 3 cell lines showed immunologic cross reactions.

Animals↗
PubMed1985

Terminal differentiation of cord blood lymphocytes induced by thymosin fraction 5 and thymosin alpha 1.

Cord blood lymphocytes (CBL) have been shown to be functionally immature compared with normal circulating adult lymphocytes (NAL). Differentiation of T cells is associated with changes in surface antigenic markers and in the pattern of purine degradative enzymes. Previous studies have demonstrated that thymosin fraction 5 (TMS-F5) and thymosin alpha 1 (TMS-alpha 1) can induce in vitro differentiation of murine T-cell precursors and human thymocytes. We have investigated the effects of TMS-F5 and TMS-alpha 1 on the pattern of the purine degradative enzymes adenosine deaminase, purine nucleoside phosphorylase, and ecto-5'-nucleotidase (5'NT) of CBL and on the phenotypic markers from the OKT series 3, 4, 8 and 11. Other than a significantly reduced level of 5'NT activity (P less than 0.001) and an elevated percentage of OKT4+ cells (P less than 0.01), CBL demonstrated the same immunological and biochemical patterns as NAL. Incubation of CBL with TMS-F5 (150 micrograms/ml) and TMS-alpha 1 (1 microgram/ml) for 40 h caused a significant rise in 5'NT level and decrease of cells positive for OKT4, resulting in a pattern characteristic of NAL. Thus TMS-F5 might induce the terminal differentiation of CBL, and TMS-alpha 1 seemed to be the active component.

5'-Nucleotidase↗
PubMed1981

[Structure of the enzootic cattle leukosis virus. 1. Biophysicochemical characterization of several virus-specific components].

Concentrated virus material partially purified, after having been obtained from permanent cell cultures, was allowed to undergo repeated gradient centrifugation for an analysis of density and sedimentation. Serological tests were conducted, in that context, together with electron microscopy and gel electrophoresis. Isodensities of the virion were 1.17 g/ml in CsCl solution or 1.16 g/ml in saccharose solution. The average densities of the internal bodies, between 45 nm and 80 nm in diameter, were measured by electron microscopy and accounted for something between 1.32 g/ml and 1.34 g/ml in CsCl solution or between 1.22 g/ml and 1.24 g/ml up to 1.28 g/ml in saccharose solution. Four revertase-positive components, 915 S, 704 S, 469 S and 264 S +/- 40 S, were found in flattened cane-sugar gradients. conclusions for non-invasive ultracentrifugation in the virus were drawn from those high S-values. High-titre mixed antigens, virus-specific bands from the density gradients, and washed antigen-antibody precipitates were investigated by the authors by means of slab-gel electrophoresis. Molecular weights of 53 kilodalton (kD) and 24 kD were recorded from the major components. There also were polypeptides weighing 10 kD, 12 kD, 15.6 kD, 42.5 kD, 63 kD, and 70 kD.

Animals↗
PubMed1980

[Derivatives of 6,7-dimethoxy-1-thiaisochroman-1,1-dioxide and 3.4-dihydro-6,7-dimethoxy-2H-1,2-benzothiazine-1,1-dioxide (author's transl)].

The authors deal with the synthesis of 3-substituted 6,7-dimethoxy-1-thiaisochroman-1,1-dioxide and 3,4-dihydro-6,7-dimethoxy-2H-1,2-benzothiazine-1,1-dioxide derivatives. The compounds in the first-named group were found to exert effects on the central nervous system, those produced by the basic amides being particularly marked, which differ from those of currently used psychopharmacological agents.

Amides↗