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1.
The effect of multi-ingredient intra- versus extra-cellular buffering supplementation combined with branched-chain amino acids and creatine on exercise-induced ammonia blood concentration and aerobic capacity in taekwondo athletes.
Durkalec-Michalski, K, Kusy, K, Główka, N, Zieliński, J
Journal of the International Society of Sports Nutrition. 2021;(1):48
Abstract
BACKGROUND This study aimed to investigate the effect of multi-ingredient intra- (BA) versus extra- (ALK) cellular buffering factor supplementation, combined with the customary intake of branched-chain amino acids (BCAA) and creatine malate (TCM), on body composition, exercise variables, and biochemical and hematological parameters in 9 elite taekwondo athletes. METHODS Eight-week randomized double-blind crossover BA (5.0 g·day-1 of β-alanine) versus ALK (0.07 g·kgFFM-1·day-1 of sodium bicarbonate) supplementation combined with BCAA (0.2 g·kgFFM-1·day-1) and TCM (0.05 g·kgFFM-1·day-1) during a standard 8-week taekwondo training period was implemented. In the course of the experiment, body composition (dual X-ray absorptiometry), aerobic capacity (ergospirometric measurements during an incremental treadmill test until exhaustion), and exercise blood biomarkers concentrations were measured. Data were analyzed using repeated measures within-between interaction analysis of variance with the inclusion of experimental supplementation order. RESULTS The maximum post-exercise blood ammonia concentration decreased in both groups after supplementation (from 80.3 ± 10.6 to 72.4 ± 10.2 µmol∙L-1, p = 0.013 in BA; from 81.4 ± 8.7 to 74.2 ± 8.9 µmol∙L-1, p = 0.027 in ALK), indicating reduced exercise-related adenosine triphosphate degradation. However, no differences were found in body composition, aerobic capacity, blood lactate concentration, and hematological parameters after neither BA (combined with BCAA and TCM) nor ALK (combined with BCAA and TCM) supplementation. CONCLUSIONS In highly trained taekwondo athletes, neither extra- nor intracellular buffering enhancement resulting from BA and ALK supplementation, combined with BCAA and TCM treatment, affects body mass and composition, maximum oxygen uptake, and hematological indices, even though certain advantageous metabolic adaptations can be observed.
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2.
Primary hyperammonaemia: Current diagnostic and therapeutic strategies.
Häberle, J
Journal of mother and child. 2020;(2):32-38
Abstract
Primary hyperammonaemia is a term to describe an elevation of ammonia in blood or plasma due to a defect within the urea cycle, which is the pathway responsible for ammonia detoxification and arginine biosynthesis. Urea cycle disorders (UCDs) are rare diseases caused by genetic defects affecting any of the six enzymes or two transporters that are directly involved in the urea cycle function.The clinical situation is variable and largely depends on the time of onset. Newborns who are often affected by hyper-ammonaemic encephalopathy carry a potential risk of severe brain damage, which may lead to death. Outside the neonatal period, symptoms are very unspecific but most often neurological (with wide variability), psychiatric and/or gastrointestinal. Early identification of patients is extremely important to start effective treatment modalities immediately. The acute management includes detoxification of ammonia, which often requires extracorporeal means such as haemodialysis, and the use of intravenous drugs that work as nitrogen scavengers. Long-term management of patients with UCDs consists of a low-protein diet, which needs to be balanced and supplemented to avoid deficiencies of essential amino acids, trace elements or vitamins and the use of nitrogen scavengers.The reader will find here a brief overview describing the most relevant aspects of the clinical management of UCDs in an attempt to raise awareness for this important group of rare diseases.
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Microbial taxonomic, nitrogen cycling and phosphorus recycling community composition during long-term organic greenhouse farming.
Ding, GC, Bai, M, Han, H, Li, H, Ding, X, Yang, H, Xu, T, Li, J
FEMS microbiology ecology. 2019;(5)
Abstract
Understanding the interplay between the farming system and soil microbiomes could aid the design of a sustainable and efficient farming system. A comparative greenhouse experiment consisting of organic (ORG), integrated (INT) and conventional (CON) farming systems was established in northern China in 2002. The effects of 12 years of organic farming on soil microbiomes were explored by metagenomic and 16S rRNA gene amplicon sequencing analyses. Long-term ORG shifted the community composition of dominant phyla, especially Acidobacteria, increased the relative abundance of Ignavibacteria and Acidobacteria Gp6 and decreased the relative abundance of Nitrosomonas, Bacillus and Paenibacillus. Metagenomic analysis further revealed that relative abundance of ammonia oxidizing microorganisms (Bacteria and Archaea) and anaerobic ammonium oxidation bacteria decreased during ORG. Conversely, the relative abundance of bacteria-carrying periplasmic nitrate reductases (napA) was slightly higher for ORG. Long-term organic farming also caused significant alterations to the community composition of functional groups associated with ammonia oxidation, denitrification and phosphorus recycling. In summary, this study provides key insights into the composition of soil microbiomes and long-term organic farming under greenhouse conditions.
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4.
Mechanistic insight, diagnosis, and treatment of ammonia-induced hepatic encephalopathy.
Fiati Kenston, SS, Song, X, Li, Z, Zhao, J
Journal of gastroenterology and hepatology. 2019;(1):31-39
Abstract
Hepatic encephalopathy is a neuropsychological syndrome due to biochemical disturbance of brain function in advanced liver disease patients. Diagnosis and treatment of the condition is very demanding and has negative toll on finances with increased healthcare utilization. The pathophysiology is not completely understood; however, there is evidence that ammonia plays an important role in the etiology. Conventional methods of solely relying on blood ammonia level to diagnose hepatic encephalopathy did not help much; likewise, the use of lactulose alone in treating hepatic encephalopathy has also been discouraged. This paper analyzed the current knowledge regarding the mechanism of how ammonia disrupts the normal brain function as well as the use of latest diagnosing tools including those under development to evaluate the neuropsychiatric state of patients and their quality of life. The efficacies of lactulose and rifaximin combination for short-term and long-term treatment in addition to nutritional interventions and other drugs undergoing clinical trials were also reviewed.
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5.
Sarcopenia: Ammonia metabolism and hepatic encephalopathy.
Jindal, A, Jagdish, RK
Clinical and molecular hepatology. 2019;(3):270-279
Abstract
Sarcopenia (loss of muscle mass and/or strength) frequently complicates liver cirrhosis and adversely affects the quality of life; cirrhosis related liver decompensation and significantly decreases wait-list and post-liver transplantation survival. The main therapeutic strategies to improve or reverse sarcopenia include dietary interventions (supplemental calorie and protein intake), increased physical activity (supervised resistance and endurance exercises), hormonal therapy (testosterone), and ammonia lowering agents (L-ornithine L-aspartate, branch chain amino acids) as well as mechanistic approaches that target underlying molecular and metabolic abnormalities. Besides other factors, hyperammonemia has recently gained attention and increase sarcopenia by various mechanisms including increased expression of myostatin, increased phosphorylation of eukaryotic initiation factor 2a, cataplerosis of α ketoglutarate, mitochondrial dysfunction, increased reactive oxygen species that decrease protein synthesis and increased autophagy-mediated proteolysis. Sarcopenia contributes to frailty and increases the risk of minimal and overt hepatic encephalopathy.
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6.
The roles of free ammonia (FA) in biological wastewater treatment processes: A review.
Liu, Y, Ngo, HH, Guo, W, Peng, L, Wang, D, Ni, B
Environment international. 2019;:10-19
Abstract
Free ammonia (FA) can pose inhibitory and/or biocidal effects on a variety of microorganisms involved in different biological wastewater treatment process, which is widely presented in wastewater treatment plants (WWTPs) due to the high levels of ammonium in the systems. This review article gives the up-to-date status on several essential roles of FA in biological wastewater treatment processes: the impacts of FA, mechanisms of FA roles, modeling of FA impacts, and implications of FA for wastewater treatment. Specifically, the impacts of FA on both wastewater and sludge treatment lines were firstly summarized, including nitrification, denitrification, anaerobic ammonium oxidation (Anammox), enhanced biological phosphorus removal and anaerobic processes. The involved mechanisms were then analyzed, which indicated FA inhibition can slow specific microbial activities or even reconfigure the microbial community structure, likely due to negative impacts of FA on intracellular pH, specific enzymes and extracellular polymeric substances (EPS), thus causing cell inactivation/lysis. Mathematical models describing the impact of FA on both wastewater and sludge treatment processes were also explored to facilitate process optimization. Finally, the key implications of FA were identified, that is FA can be leveraged to substantially enhance the biodegradability of secondary sludge, which would further improve biological nutrient removal and enhance renewable energy production.
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7.
Glutamate production from ammonia via glutamate dehydrogenase 2 activity supports cancer cell proliferation under glutamine depletion.
Takeuchi, Y, Nakayama, Y, Fukusaki, E, Irino, Y
Biochemical and biophysical research communications. 2018;(1):761-767
Abstract
Cancer cells rapidly consume glutamine as a carbon and nitrogen source to support proliferation, but the cell number continues to increase exponentially after glutamine is nearly depleted from the medium. In contrast, cell proliferation rates are strongly depressed when cells are cultured in glutamine-free medium. How cancer cells survive in response to nutrient limitation and cellular stress remains poorly understood. In addition, rapid glutamine catabolism yields ammonia, which is a potentially toxic metabolite that is secreted into the extracellular space. Here, we show that ammonia can be utilized for glutamate production, leading to cell proliferation under glutamine-depleted conditions. This proliferation requires glutamate dehydrogenase 2, which synthesizes glutamate from ammonia and α-ketoglutarate and is expressed in MCF7 and T47D cells. Our findings provide insight into how cancer cells survive under glutamine deprivation conditions and thus contribute to elucidating the mechanisms of tumor growth.
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8.
The Eponymous Cofactors in Cytochrome P460s from Ammonia-Oxidizing Bacteria Are Iron Porphyrinoids Whose Macrocycles Are Dibasic.
Smith, MA, Lancaster, KM
Biochemistry. 2018;(3):334-343
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Abstract
The enzymes hydroxylamine oxidoreductase and cytochrome (cyt) P460 contain related unconventional "heme P460" cofactors. These cofactors are unusual in their inclusion of nonstandard cross-links between amino acid side chains and the heme macrocycle. Mutagenesis studies performed on the Nitrosomonas europaea cyt P460 that remove its lysine-heme cross-link show that the cross-link is key to defining the spectroscopic properties and kinetic competence of the enzyme. However, exactly how this cross-link confers these features remains unclear. Here we report the 1.45 Å crystal structure of cyt P460 from Nitrosomonas sp. AL212 and conclude that the cross-link does not lead to a change in hybridization of the heme carbon participating in the cross-link but rather enforces structural distortions to the macrocycle away from planarity. Time-dependent density functional theory coupled to experimental structural and spectroscopic analysis suggest that this geometric distortion is sufficient to define the spectroscopic properties of the heme P460 cofactor and provide clues toward establishing a relationship between heme P460 electronic structure and function.
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Ammonia Inhalation Does Not Increase Deadlift 1-Repetition Maximum in College-Aged Male and Female Weight Lifters.
Vigil, JN, Sabatini, PL, Hill, LC, Swain, DP, Branch, JD
Journal of strength and conditioning research. 2018;(12):3383-3388
Abstract
Vigil, JN, Sabatini, PL, Hill, LC, Swain, DP, and Branch, JD. Ammonia inhalation does not increase deadlift 1-repetition maximum in college-aged male and female weight lifters. J Strength Cond Res 32(12): 3392-3397, 2018-Ammonia inhalant use by powerlifters and weight lifters is a prevalent practice with little research support for improved performance. The purpose of this study was to investigate the effects of ammonia as a stimulant on athletic performance during a deadlift 1-repetition maximum (1RM) absolute strength test. Subjects (men: n = 10, mean ± SD age = 21 ± 1 year, mass = 72.5 ± 6.8 kg; and women: n = 10, age = 22 ± 5 years, mass = 66.2 ± 8.1 kg) were required to have at least 2 years of resistance training experience while lacking a history of asthma, lightheadedness, fainting, anaphylaxis, sickle cell traits, and other respiratory disorders. After a baseline 1RM test, subjects were paired by 1RM performance and gender, then randomly assigned in a counterbalanced treatment order to control (water) or ammonia trials after a minimum 72-hour recovery period for another 1RM test involving attempts at 100.0, 102.5, 105.0, and 107.5% of the established 1RM value. Testing was then repeated after the minimum rest period for the remaining trial. Results revealed the expected gender main effect for absolute deadlift 1RM (93.0 ± 29.5 [women]; 152.0 ± 29.5 kg [men]; p < 0.001), but no trial main effect (p = 0.874) or gender by trial interaction effect (baseline = 93.0 ± 15.3, 151.8 ± 42.3 kg; water = 92.0 ± 12.5, 150.9 ± 37.8 kg; ammonia = 92.5 ± 16.4, 153.4 ± 37.9 kg) for women and men, respectively (p = 0.559). Within the limitations of this study, there is no support for the practice of ammonia inhalation to improve deadlift 1RM in training or competition.
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The impact of ammonia levels and dialysis on outcome in 202 patients with neonatal onset urea cycle disorders.
Hediger, N, Landolt, MA, Diez-Fernandez, C, Huemer, M, Häberle, J
Journal of inherited metabolic disease. 2018;(4):689-698
Abstract
Neonatal onset hyperammonemia in patients with urea cycle disorders (UCDs) is still associated with high morbidity and mortality. Current protocols consistently recommend emergency medical and dietary management. In case of increasing or persistent hyperammonemia, with continuous or progressive neurological signs, dialysis is performed, mostly as ultima ratio. It is presently unknown whether the currently defined ammonia threshold (e.g., at 500 μmol/L) to start dialysis is useful to improve clinical outcome. A systematic review of clinical and biochemical data from published neonatal onset UCD patients was performed to identify factors determining clinical outcome and to investigate in which clinical and biochemical setting dialysis was most effective. A total of 202 patients (118 proximal and 84 distal UCDs) described in 90 case reports or case series were included according to predefined inclusion/exclusion criteria. Median age at onset was three days and mean ammonia that triggered start of dialysis was 1199 μmol/L. Seventy-one percent of all patients received any form of dialysis. Total mortality was 25% and only 20% of all patients had a "normal" outcome. In general, patients with higher ammonia levels were more likely to receive dialysis, but this had for most patients no influence on outcome. In conclusion, in severe neonatal onset hyperammonemia, the current practice of dialysis, which effectively clears ammonia, had no impact on outcome. It may be essential for improving outcome to initiate all available treatment options, including dialysis, as early as possible.