The metabolic products of heterotrophic (dark) CO(2) fixation by Euglena gracilis Klebs strain Z Pringsheim were separated and identified. They consisted of amino acids, phosphorylated compounds, tricarboxylic acid cycle intermediates, and nucleotides. Exposure of the cells to NH(4) (+) after a period of NH(4) (+) deprivation stimulated heterotrophic CO(2) fixation almost 4-fold, modifying the ...

Galanin (GAL) is a 29-amino-acid residue peptide originally isolated from porcine upper small intestine. GAL exhibits various physiological activities, such as effects on hormones release, smooth muscles contractions, gastric acid secretion, neurons degeneration and feeding. One of the biological actions of GAL is the inhibition of insulin secretion from the pancreatic beta-cells. In our studie...

Experiments were conducted to determine the pathway of melamine metabolism by Klebsiella terragena (strain DRS-1) and the effect of added NH(inf4)(sup+) on the rates and extent of melamine metabolism. In the absence of added NH(inf4)(sup+), 1 mM melamine was metabolized concomitantly with growth. Ammeline, ammelide, cyanuric acid, and NH(inf4)(sup+) accumulated transiently in the culture medium...

PURPOSE In chicks, plus defocus retards eye growth, thickens the choroid, and activates glucagonergic amacrine cells, probably releasing glucagon. Glucagon receptor antagonists (expected to inhibit compensation to plus defocus) and agonists (expected to block myopia induction by form deprivation) were administered to eyes of chicks, to test the hypothesis that glucagon mediates the induction of...

Trypsin activates proteinase-activated receptor-2 (PAR(2)) by a mechanism that involves the release of a tethered receptor-activating sequence. We have identified two peptides, FSLLRY-NH(2) (FSY-NH(2)) and LSIGRL-NH(2) (LS-NH(2)) that block the ability of trypsin to activate PAR(2) either in PAR(2)-expressing Kirsten virus-transformed kidney (KNRK) cell lines or in a rat aorta ring preparation....

7-Aminocephalosporanic acid wastewater usually contains high concentrations of ammonium (NH₄⁺-N), which is known to inhibit nitrification during biological treatment processes. Chemical precipitation is a useful technology to remove ammonium from wastewater. In this paper, the removal of ammonium from 7-aminocephalosporanic acid wastewater was studied. The optimum pH, molar ratio, and various c...

Ammonia toxicity and cerebral oxidative metabolism. Am. J. Physiol. 200(3) : 420-424. 1961. -Effects of NH&l on oxidative metabolism of cat cerebral cortex slices and mitochondria incubated in vitro were studied. In slices, addition of IO mM NH&l to the incubation medium resulted in significant (16%) reduction of O2 uptake, doubling of lactic acid production and marked increase of glucose utili...

Here we show that in aging Saccharomyces cerevisiae (budding yeast) cells, NH(4) (+) induces cell death associated with shortening of chronological life span. This effect is positively correlated with the concentration of NH(4) (+) added to the culture medium and is particularly evident when cells are starved for auxotrophy-complementing amino acids. NH(4) (+)-induced cell death is accompanied ...

The reaction of CH₃NH₂ with O₂ on the singlet potential energy surfaces (PES) was carried out using the B3LYP, CCSD(T) and G3B3 theoretical approaches along with 6-311++G(3df,3pd) basis set. The suggested mechanism for the title reaction consists of one pre-reactive complex. From the pre-reactive complex, nine types of products, CH2NH+H2O2, CH3NH+OOH,...

The aim of the current study was to investigate the feasibility of membrane contactors for continuous ammonia (NH₃-N) removal in an anaerobic digestion process and to counteract ammonia inhibition. Two laboratory anaerobic digesters were fed slaughterhouse wastes with ammonium (NH₄⁺) concentrations ranging from 6 to 7.4 g/L. One reactor was used as reference reactor without any ammonia removal....