Increased ammonium (NH(4)(+)/NH(3)) in the brain is a significant factor in the pathophysiology of hepatic encephalopathy, which involves altered glutamatergic neurotransmission. In glial cell cultures and brain slices, glutamate uptake either decreases or increases following acute ammonium exposure but the factors responsible for the opposing effects are unknown. Excitatory amino acid transpor...

Formaldehyde gas, generated by the depolymerization of paraformaldehyde and in the presence of water vapor, has been traditionally used for biological decontamination of equipment and spaces utilized for research with a susceptible biological agent. This gas has often been neutralized with ammonia gas, generated by the thermal decomposition of ammonium bicarbonate or ammonium carbonate. An elem...

Evidence is presented that intracellular ammonium is trapped in vacuoles of maize (Zea mays L.) root tips because of rapid movement of ammonia between cytoplasm and vacuoles. The concentration of cytoplasmic ammonium is estimated to be <15 mum at extracellular ammonium concentrations up to 1 mm. The implications for pathways of ammonium assimilation are discussed.

The causal role of ammonium in hepatic encephalopathy was identified in 1930s. Astroglial cells are primary cellular elements of hepatic encephalopathy which conceptually, can be considered a toxic astrogliopathology. Previously we have reported that acute exposure to ammonium activated ouabain/Na,K-ATPase signalling pathway, which includes Src, EGF receptor, Raf, Ras, MEK and ERK1/2. Chronic i...

In R. capsulatus synthesis and activity of the molybdenum and the alternative nitrogenase is controlled at three levels by the environmental factors ammonium, molybdenum, light, and oxygen. At the first level, transcription of the nifA1, nifA2, and anfA genes--which encode the transcriptional activators of all other nif and anf genes, respectively--is controlled by the Ntr system in dependence ...

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...