The control of polyamine synthesis in neoplastia cells is com plex and incompletely understood. Using murine lymphoma cells deficient in methylthioadenosine (MTA) phosphorylase, we have analyzed the role of MTA in the regulation of ornithine decarboxylase and S-adenosylmethionine (SAM) decarboxylase, the two rate-limiting enzymes in the polyamine-biosynthetic pathway. The addition of MTA to the...

Topical application of retinole acid to mouse skin led to a dramatic inhibition of phorbol ester (12-O-tetradecanoylphorbol-13-acetate)-induced epidermal ornithine decarboxylase (EC 4.1.1.17) activity, an event proposed to be essen tial for tumor promotion. The degree of inhibition was de pendent on the dose and time of application of retinoic acid. In contrast, treatment with retinoic acid did...

Polymerase chain reaction (PCR) amplification of multiple templates using common primers is used in a wide variety of molecular biological techniques. However, abundant templates sometimes obscure the amplification of minor species containing the same primer sequences. To overcome this challenge, we used oligoribonucleotides (ORNs) to inhibit amplification of undesired template sequences withou...

The present-day distribution patterns of the cicadas of Wallacea, New Guinea, and the West Pacific reflect the extremely complex geotectonic history of that area. The patterns found in two unrelated monophyletic groups of cicadas (Insecta, Homoptera, Cicadoidea), the subtribe Cosmopsaltriaria and the tribe Chlorocystini with its sister tribe Prasiini, are analysed and related to data from the g...

Periodical Cicada Brood Borders are Maintained by Competition and Allee Dynamics ....................................................................................... 136 Andrew LIEBHOLD, Richard KARBAN Induced Response of Oak Trees to Raffaelea quercivora as a Possible Defense against Japanese Oak Wilt Caused by the Ambrosia Fungus Carried by an Ambrosia Beetle .................................