Six Haemophilus influenzae strains could not be classified as biotypes I through VII. The strains were indole, urease, and ornithine decarboxylase negative. We propose that they be classified as biotype VIII, a previously unreported biotype.

We examined thyroidectomized, normal and hyperthyroid rats and found that ornithine decarboxylase activity was directly correlated with thyroid functional state in heart and liver and unaffected in brain, testes and spleen, phenomena that correlate with the known effect of thyroid hormone on protein synthesis.

Antizyme, a protein inhibitor of ornithine decarboxylase (ODC), was shown to be induced in mouse kidney by repeated injection of putrescine. Antizyme was also present as a complex with ODC in the kidney of untreated mouse. The amount of the renal ODC-antizyme complex was 3-fold higher in male mice than in female mice. On the contrary, the proportion of ODC present as a complex with antizyme was...

Ornithine decarboxylase (ODC), a ubiquitin-independent substrate of the proteasome, is a homodimeric protein with a rate-limiting function in polyamine biosynthesis. Polyamines regulate ODC levels by a feedback mechanism mediated by ODC antizyme (OAZ). Higher cellular polyamine levels trigger the synthesis of OAZ and also inhibit its ubiquitin-dependent proteasomal degradation. OAZ binds ODC mo...

Antizyme inhibitor was highly purified from rat liver by using affinity chromatography. It has some structural resemblance to ornithine decarboxylase (ODC), as judged from Mr, immunoreactivity and reversible binding with antizyme. However, unlike hepatic amounts of ODC and ODC-antizyme complex, that of antizyme inhibitor did not show much fluctuation upon putrescine treatment, whereas it decrea...

Ornithine decarboxylase (OIK ) belongs to a multigene family and some of these may very well be nonfunctional (pseudogenes). We isolated an ODC gene from a human chromosome 2-specific library and transfected the gene into ODC-deficient Chinese hamster ovary cells to directly demonstrate that this ODC gene is functional and OIK is essential for cell proliferation. After screening 2.5 x 10* plaqu...

In cultured mammary explants from both virgin and midpregnant mice which contained a low and a high initial level of putrescine, respectively, addition of an ornithine decarboxylase inhibitor, DL-a-hydrazino-Saminovaleric acid at the onset of culture prevented an early, “osmolarity-sensitive” rise in the putrescine level that occurred prior to induction of DNA synthesis by insulin. In the pres...

Metabolism as well as function of the three amino acids, L-arginine, L-citrulline, and Lornithine, are closely intertwined and related to the homeostasis of nitric oxide at the tissue and cellular levels. For the three compounds data on neural tissue and CSF levels are summarized and localization in brain mainly derived from immunohistochemical experiments is reported. A complex pattern of diff...