To the editor: The case report by Tuchscherer and Rehman is indeed interesting. However, this article requires that we look more closely at what is meant by urinary ammonium being measured. The renal response to metabolic acidosis is to increase excretion of hydrogen ion in the form of ammonium; the measurement of its urinary concentration is important when trying to identify the cause of the a...

The relationship between ammonium accumulation and senescence of detached rice leaves caused by excess cadmium (Cd) was investigated. CdCl(2) was effective in increasing ammonium content in detached rice leaves under both light and dark conditions. Both CdCl(2) and CdSO(4) induced ammonium accumulation in detached rice leaves, indicating that ammonium accumulation is induced by Cd ions. CdCl(2)...

The fate of bacteria in human urine was studied after inoculation of small numbers of Escherichia coli and other bacterial strains commonly implicated in urinary tract infection. Urine from normal individuals was often inhibitory and sometimes bactericidal for growth of these organisms. Antibacterial activity of urine was not related to lack of nutrient material as addition of broth did not dec...

Glufosinate ammonium diminished developments of rice (Oryza sativa) blast and brown leaf spot in 35S:bar-transgenic rice. Pre- and postinoculation treatments of this herbicide reduced disease development. Glufosinate ammonium specifically impeded appressorium formation of the pathogens Magnaporthe grisea and Cochliobolus miyabeanus on hydrophobic surface and on transgenic rice. In contrast, con...

Glutamine synthetase (GS) catalyzes a reaction that incorporates ammonium into glutamate and yields glutamine in the cytosol and chloroplasts. Although the enzymatic characteristics of the GS1 isozymes are well known, their physiological functions in ammonium assimilation and regulation in roots remain unclear. In this study we show evidence that two cytosolic GS1 isozymes (GLN1;2 and GLN1;3) c...

The ammonium permease Mep2p mediates ammonium uptake and also induces filamentous growth in the human-pathogenic yeast Candida albicans in response to nitrogen limitation. The C-terminal cytoplasmic tail of Mep2p contains a signaling domain that is not required for ammonium transport but is essential for Mep2p-dependent morphogenesis. Progressive C-terminal truncations showed Y433 to be the las...

Ammonium suppresses nitrogenase activity in Anabaena flos-aquae (Lyng) Breb. at all pH values tested. l-Methionine-dl-sulfoximine at 1 millimolar totally inhibited glutamine synthetase, and 10 micromolar partially inhibited. Both concentrations protected nitrogenase activity from ammonium-induced suppression at pH 7.1 and 8.1. At pH 9.3 and 10.2, methionine sulfoximine did not alleviate the sup...