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PubMed2000

[Is there a delay in bathing the external eye in the treatment of ammonia eye burns? Comparison of two ophthalmic solutions: physiological serum and Diphotérine].

PURPOSE: An experimental animal study was conducted to analyze the delay for ocular bathing in the treatment of severe ocular ammonia burns. Two solutions of ocular wash, saline solution and Diphotérine were compared. MATERIAL: and methods: The study included 23 eyes of New Zealand albino rabbits that received for 1 minute 100 microl of 15.3% ammonium solution. Each eye was then washed with 250 of saline solution or 250ml Diphotérine after a delay of 1, 3, 5, 10 or 30 minutes. Effects were assessed on the basis of changes in anterior chamber pH, ammonia concentration in the anterior chamber, and cytopathology examination of the burned corneas. RESULTS: Ocular wash with Diphotérine in the first minutes following ocular burn induced an inflexion of the pH curve unlike ocular wash with saline solution. At 30 minutes, there was no inflexion of the pH curve and the ammonia concentration in the anterior chamber was low. Contrary to ocular wash using Diphotérine, stromal edema was seen at cytopathological analysis after washing with saline solution. CONCLUSIONS: This study provides evidence of the interest of ocular bathing in the first minutes following ocular burn by ammonia. The efficacy of external ocular washing with Diphotérine was proven by biochemical and cytopathological demonstrations. The importance of sequelae were related to the degree of initial stromal edema.

Ammonia↗
PubMed2001

In vivo evaluation of ammonia plasma modified ePTFE grafts for small diameter blood vessels replacement. A preliminary report.

BACKGROUND: Today, saphenous veins are most frequently used to reconstruct occluded or diseased small diameter vessels (< or =6 mm in diameter). However, these veins are unavailable in 30-40% of patients. In such a situation, prosthetic grafts provide the only alternative. Since an endothelial cell (EC) lining, important for maintaining a haemostatic-thrombotic balance, does not develop onto the intima of implanted grafts in humans, these grafts occlude within a short period of time. The failure of vascular grafts is attributed to their characteristics which are nonconducive towards endothelial cell adhesion, spreading and growth. In order to examine whether the patency of vascular grafts can be improved by the surface modification of grafts' intima, small diameter grafts were modified by a novel ammonia plasma treatment to enhance their interactions with EC. METHODS: Through laparotomy, ammonia plasma treated ePTFE (4 mm in diameter) grafts (n=3) and control untreated grafts (n=6) were implanted into the distal infrarenal aorta of rabbits. At appropriate time, grafts and adherent tissue were removed, fixed, stained and embedded in Poly/Bed 812. Light microscopic examination of thin sections cut from the proximal and distal anastomatic and midportion segments of explanted grafts was carried out. RESULTS: In control group studies, all animals developed lower limb paraplegia within seven days of implantation. Light microscopic examination of explanted control grafts showed that control grafts were obstructed by thrombosis/intimal hyperplasia. However, ammonia plasma modified explanted grafts, after one month of transplantation, revealed an endothelial cell-like lining that covered the grafts' inner surfaces. Accordingly, these grafts remained patent in animals. CONCLUSIONS: The grafts' surfaces that are made conducive to EC adhesion and proliferation and host response may influence endothelial regeneration. It is hoped that the combination of angiogenic molecules (i.e. endothelial cell specific growth factors such as VEGF) with ammonia plasma modified grafts may provide further insight into the development of ideal small diameter prosthesis.

Ammonia↗
PubMed2002

Ammonia recovery from high strength agro industry effluents.

The aim of the study was to investigate ammonia recovery from high strength agro industry effluents involving significant amounts of ammonia, by applying magnesium ammonium phosphate (MAP) precipitation technology. Two types of industrial effluents have been tested in the study. The first plant was an opium alkaloid processing industry and the second one was a baker's yeast industry. High chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and unacceptable dark brown color characterized effluents from both industries. Effluents from the biologically treated opium alkaloid and baker's yeast industries were both applied at the stoichiometric ratio (Mg:NH4:PO4 = 1:1:1) and above the stoichiometric ratio (Mg:NH4:PO4 = 1.1:1:1.1) to MAP precipitation. NH4 removals of 61-80% were achieved at the pH of 9.2 at the stoichiometric ratio, whereas 83% NH4 removal was obtained at the pH of 9.2 above the stoichiometric ratio. Experimental studies performed on both anaerobically and/or aerobically treated baker's yeast and opium alkaloid industry effluents have clearly indicated that MAP precipitation was an appropriate treatment option for NH4 removal or struvite recovery from high ammonia content agro industry effluents. Additional ammonia recovery studies were conducted on ozonated and Fenton's oxidation applied effluents and these have also indicated that the amounts of struvite and the quality of MAP precipitate was increased significantly. In this framework, MAP sludge recovered from combined biological and Fenton's oxidation treatment effluents were considered as a more valuable slow release fertilizer for agricultural use.

Agriculture↗
PubMed2002

Molecular analysis of ammonia-oxidizing bacterial populations in aerated-anoxic orbal processes.

Aerated-anoxic processes operate under the principle that small additions of oxygen to an anoxic reactor induce simultaneous nitrification and denitrification. In these systems, ammonia oxidation in the anoxic zone can easily account for 30-50% of the total nitrification in the reactor, even though the dissolve oxygen concentration is usually below detection limit. To investigate whether the nitrification efficiency in aerated-anoxic processes was due to the presence of specialized ammonia-oxidizing bacteria (AOB), an analysis of the AOB population in an aerated-anoxic Orbal process and a conventional nitrogen removal process was carried out using phylogenetic analyses based on the ammonia monooxygenase A (amoA) gene. Terminal restriction fragment length polymorphism (TRFLP) analyses revealed that Nitrosospira-like organisms were one of the major contributors to ammonia oxidation in a full-scale aerated-anoxic Orbal reactor. However, the relative populations of Nitrosospira-like and Nitrosomonas-like AOB were not constant and appeared to have seasonal variability. Cloning and sequence comparison of amoA gene fragments demonstrated that most of the AOB in the aerated-anoxic Orbal process belonged to the Nitrosospira sp. and Nitrosomonas oligotropha lineages. The abundance of Nitrosospira-like organisms in aerated-anoxic reactors is significant, since this group of AOB has not been usually associated with nitrification in wastewater treatment plants.

Ammonia↗
PubMed1975

Effects of ammonia intoxication and liver injury on rat brain glutamate-dehydrogenase and glutaminase activity.

Glutamate dehydrogenase (GDH) and glutaminase activity in the rat brain was altered by chronic ammonia intoxication, subacute liver injury induced by CCl4 or digalactosamine, and the combination of them. GDH activity was found to increase considerably in ammonia intoxication without liver damage, probably as a result of enzyme induction. GDH activity failed to increase, while glutaminase was appreciably elevated. when ammonia intoxication was associated with hepatic injury. Toxicological studies have indicated that these changes in brain enzyme levels may be involved in the mechanism of ammonia neurotoxicity.

Ammonia↗
PubMedDate not supplied

[Ammonia-neutralizing function of hepatocytes after experimental liver resection].

The experimental study has established that a 15-20% resection of a hepatic mass in healthy rats inhibits glutamine formation in hepatocytes and stimulates its decomposition in liver cells promoting ammonia accumulation in the operated liver. The hepatocyte urea synthetizing cycle can not prevent accumulation of ammonia in the liver and raise their urea content even if arginase activity is high. Inhibition of GDG activity in the operated liver not only limits formation of ammonia during glutamate deamination but also results in glutamine deamination inhibition in hepatocytes. These disorders of hepatocytic ammonia neutralizing function persist for 21 days after hepatic resection.

Ammonia↗
PubMed2003

Treatment of ammonia intoxication in rats with urea cycle amino acids, furosemide and fluids.

Three hundred sixty-seven male Wistar rats were used to compare the efficiency of urea cycle amino acids (arginine, citrulline and ornithine; Group O), furosemide (Group F), and fluid therapy (saline solution; Group FT) to treat ammonia toxicity. Rats were injected ip initially with an ammonium acetate solution at 99.9% of the lethal dose. Three min later the rats were allocated randomly to Group C (control, received 1.2 mL distilled water). Group O (amino acids listed earlier, 2 mmol/kg bw), Group F (furosemide, 2 mg/kg bw), Group FT (7mL saline), or Groups O+F, O+FT, F+FT, or O+F+FT. All treatments were given ip except for Group F given im injections. Plasma ammonia, urea and creatinine, and hematocrit and pulmonary dry matter were determined. The highest survival rates were obtained with O+FT (57%) and O+F+FT (62.5%); only 6% of the controls survived. Plasma ammonia levels were ten-fold lower in rats treated with O+FT and O+F+FT (p<0.0001). Fatally-poisoned rats had higher plasma ammonia, creatinine and hematocrit and exhibited pulmonary edema. Surviving rats had lower plasma urea. Animals given treatments with O, FT and F had (p<0.005) higher urea, lower creatinine and less severe pulmonary edema, respectively, than those untreated.

Ammonia↗
PubMed2003

[Ammonia and ammonium salts: remedy and poison, myth and time honored reality].

The public interest in ammonia and its salts has risen due to the recent water crisis in Israel. The focus on their regulatory and environmental aspects has been intensified due to the elevated levels of ammonium salts in the national water system, resulting in a banning of water use in the Dan district. To the public it is commonly known that ammonia is toxic. Nevertheless, the medical view regarding ammonium salts is very different from that of ammonia gas. In contrast to the hazardous ammonia gas, its salts (such as ammonium bicarbonate) are considered to be much less toxic and are widely used as medicaments and food additives. Thus, although the presence of ammonium salts in the drinking water may indicate contamination, this is not a case of poisoning associated with toxic side effects.

Ammonia↗
PubMed1992

[Acute toxicity of ammonia in the production process of postlarvae of Penaeus paulensis Pérez-Farfante, 1967].

Larval shrimp Penaeus paulensis showed a tendency to decrease in ammonia tolerance as the larva metamorphosed from nauplius to postlarvae stage. The 24-h LC50 were 4.04, 1.70, 2.72, and 1.42 mg/l NH3-N on nauplii, zoea, mysis and postlarvae, respectively. The zoea stage and the initial postlarvae substages were very susceptible to ammonia. The 96-h LC50 values on zoea and postlarvae were 0.69 mg/l and 0.32 mg/l, against 0.80 mg/l NH3-N on mysis. The eggs of Penaeus paulensis were very affected by ammonia, which provoked a progressive decrease in the hatching rate and induced morphological deformities in hatched nauplii. A "safe level" of ammonia was estimated at 0.032 mg/l NH3-N on the basis of 24-h LC50 for eggs.

Ammonia↗
PubMed2003

[The impact of carnitine on serum ammonia concentration and lipid metabolism in patients with alcoholic liver cirrhosis].

UNLABELLED: Treatment of patients with liver cirrhosis with the signs of liver insufficiency is complex and seldom satisfactory. Carnitine, taking part in liver lipid metabolism might be a potentially effective drug. THE AIM: Of the study was to evaluate the influence of L-carnitine on serum ammonia, cholesterol and triglyceride concentrations. PATIENTS AND METHODS: Fifty patients with liver cirrhosis of alcoholic aetiology, 16 females and 34 males, aged 55 +/- 11.3 years (mean +/- SD) were included into the study. Fourteen patients were treated with L-carnitine, 25--with L-ornitine L-aspartate, 11--were not given those medicaments. All patients had proteins reduced down to 0.5 g/kg b.w. per day in their diet. The serum concentrations of ammonia, cholesterol and triglycerides were assessed on inclusion and after 28 days of treatment. RESULTS: All patients improved clinically. A significant improvement was observed in the group of patients treated with L-ornitine L-aspartate (p < 0.003), and among those treated with L-isocarnitine (p = 0.005), while evaluating the Child-Pugh score before and after treatment. The serum ammonia concentration decreased in all patients. However, among the individuals treated with L-carnitine an increase of serum cholesterol and triglyceride concentrations was observed as well (p = 0.02). CONCLUSIONS: L-carnitine lowers the serum ammonia concentration and improves lipid metabolism.

Adult↗
PubMedDate not supplied

[Association of plasma ammonia and GABA levels and the degree of hepatic encephalopathy].

Several toxic factors have been implicated in the pathogenesis of hepatic encephalopathy (PSE) among which ammonia plays a dominant role. More recently, the gamma-aminobutyric acid (GABA) hypothesis in which an increase in the GABA-ergic tone and the presence of one or more GABA/benzodiazepine receptor ligands which interact with that receptor, has been proposed. We investigated the levels of GABA and ammonia in plasma of patients with acute PSE to test the hypothesis that elevated plasma GABA levels would be found in acute encephalopathy and that GABA levels would correlate with the degree of hepatic encephalopathy. We measured plasma levels of GABA and ammonia during an acute episode of PSE, spontaneous or precipitated by gastrointestinal bleeding or sepsis, and performed assessments of PSE by the PSE index. Patients were evaluated before and two days after standard treatment with lactulose. We also measured plasma GABA levels in the hepatic vein of a selected group of patients undergoing hemodynamic studies. Plasma GABA levels were significantly higher in patients with acute PSE (458 +/- 108 pmol/mL) when compared with normal subjects (110 +/- 23 pmol/mL) (p < 0.01) although no correlation was found between plasma GABA concentration and the degree of PSE. Changes in plasma ammonia, however, correlated with improvements in the PSE index (r = 0.56; p < 0.02) and with abnormalities in the EEG (r = 0.65; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed2004

[Inhibition of aromatics on ammonia-oxidizing activity of sediment].

The inhibition of 24 aromatics on ammonia-oxidizing activity of nitrifying bacteria in sediment was measured. The effects of the kind, number and position of substituted groups on ammonia-oxidizing activity of nitrifying bacteria were discussed. The inhibition of mono-substituted benzenes on ammonia-oxidizing activity of nitrifying bacteria were in order of -OH > -NO2 > -NH2 > -Cl > -CH3 > -H. The position of substituted groups of di-substituted benzenes also affected the inhibition, and the inhibitions of dimethylbenzenes(xylene) were in order of meta-> ortho-> para-. The increase in number of substituted group on benzene-ring enhanced the inhibition of aromatics studied in this study on nitrifying bacteria. There was a linear relationship between inhibition (IC50, mumol.L-1) of aromatics on ammonia-oxidizing activity and total electronegativity (sigma E) of aromatics: lgIC50 = 14.72 - 0.91 sigma E.

Ammonia↗
PubMed2001

[Ammonia-gas poisoning: respiratory troubles evaluated by functional exploration].

The objective of our research is first to evaluate the defects in the respiratory function which have been noticed among patients suffering from ammonia poisoning during the accident at the SONACOS factory of Dakar in 1992. Secondly it is to set precisely the seriousness of the problem. This retrospective study is carried out on 50 patients examined at the Physiology and Functional Exploration Laboratory of the faculty of Medicine of Dakar University from March 1993 to October 1995. These patients have been submitted to at least two respiratory functional explorations. Ten of them have been treated for two years, thus benefiting from a spirographic control of these respiratory troubles already noticed. 58 % of the patients have developed an obstruction syndrome with the following specifities : fourteen patients out of 29 revealed a serious stoppage of the bronchi, twelve had a moderate bronchial obstruction, and three showed a minor bronchial obstruction. Besides, 34 % of the patients have developed a mixed syndrome with a minor restrictive component and a severe obstructive component. 8 % of the poisoned have presented a normal lung function testing. About the localisation of the respiration disorders at the level of the bronchial system, 61 % of the patients have shown an obstruction of the proximal, medial and distal bronchi. 26 % have presented obstruction of the distal bronchi, 13 % have shown an attack at their medial and distal bronchi. 5 patients out of 10 have shown any modification in their respiratory troubles while 3 of 10 have shown significant improvement. Then 2 out of 10 have shown degradation in their respiratory problems with an extension of bronchial obstruction. The ammonia poisoning has caused serious respiratory disorders related to the general and local toxic action of ammonia on the respiratory tract, its retention at their level and its effects on the respiratory function. The severity of the patent injuries incites to issue recommendations concerning the prevention of ammonia poisoning and the quick and efficient taking charge of the casualties in case of any accidental intoxication.

Adolescent↗
PubMedDate not supplied

[Characterization of labor conditions and state of health among ammonia nitrate producing workers].

A complicated inquiry of worker's working conditions at enterprises that are producing ammonia nitrate has been conducted. It was determined that during the production process hazardous chemical compounds were used. It was found that labor conditions of studied industry are in unfavorable state. The most important problem is air pollution with toxic gazes. The atmosphere at the enterprises producing ammonia nitrate is significantly polluted by ammonia, nitrous acid and nitrogenous gazes. Concentration of toxic substances depends on the character of the technological process. High air temperature has bad effects on health during warm periods of the year. Noise factor and general industrial vibration exceed acceptable level in the majority of working area. The figures for sickness rate of workers with temporary loss of ability for work during three years have been analyzed. It has been stated that general rate of morbidity is not high, but this index in basic group 3.6-5.1 times exceeds the analogous figure in the control group. In the structure of morbidity diseases of respiratory, musculoskeletal, cardiovascular, neural, kidney and digestive systems are frequent and they amount to 76% of the whole cases. The clinical examination of the workers with basic professions of the production of ammonia nitrate shows the frequent cases of chronic bronchitis and radiculoneuropathy. The results of function study show the damage of airways and the myocardiodystrophy. This confirms the major role of occupational- professional factors in the etiology of these pathological conditions.

Ammonia↗
PubMed2005

Anaerobic digestion of slaughterhouse waste with UF-membrane separation and recycling of permeate after free ammonia stripping.

Anaerobic digestion can adapt to free ammonia to a certain extent. During the anaerobic digestion of slaughterhouse waste, however, an ammonia concentration of up to 15 g Nl(-1) can be reached in the sludge liquid and this will even inhibit adapted sludge. To lower this concentration, a fraction of the digester liquid must therefore be continuously separated from the digested sludge and the free ammonia stripped before the liquid is recycled to the digester. A mesophilic laboratory digester was successfully operated with an ammonium concentration of 4-5g l(-1) and a pH of 8.0-8.4. After free ammonia stripping, the excess liquid was treated in a laboratory SBR for nitrogen and phosphorus removal before being added to the receiving water. The effluent had no toxic effect on daphnia and algae.

Abattoirs↗
PubMed2003

[Study on the ammonia-oxidizing bacteria from activated sludge samples by the molecular analysis].

The molecular analysis methods of PCR amplification, random cloning and sequencing were used to investigate the ammonia-oxidizing bacterial community composition and the activity of ammonia-monooxygenase (AMO) from the activated sludge samples of an industrial wastewater treatment plant receiving sewage with high ammonia concentration. It is the first time to use PCR-DGGE combined technique to analysis the difference of dominant bacterial community compositions of the activated sludge samples in China. The result showed that the ammonia-oxidizing bacteria (AOB) detected from the activated sludge samples all belong to Nitrosomonas sp. The activity of AMO, the stability of bacteria community composition and the treatment efficiency of the wastewater treatment system were improved evidently, after the activated sludge system was operated for a certain extant. It is suggested that the molecular techniques will contribute to our understanding of the diversity and function of AOB and will benefit to improve the industrial wastewater treatment system.

Ammonia↗
PubMed2005

Gastric juice ammonia and urea concentrations and their relation to gastric mucosa injury in patients maintained on chronic hemodialysis.

PURPOSE: This study was undertaken to test the hypothesis that high concentrations of urea in gastric juice would have an influence on Helicobacter pylori infection in patients maintained on chronic hemodialysis (HD). MATERIAL AND METHODS: We investigated 30 patients (17 males, 13 females; mean age 50.8 +/- 2.9 years) with end-stage renal disease (ESRD) undergoing hemodialysis treatment (HD) for at least 6 months, who were compared to 31 patients (16 males, 15 females; mean age 61.3 +/- 2.2 years) with dyspeptic symptoms. Biopsies from the gastric antrum and body were taken for histological investigation. Urea and ammonia were measured in gastric juice, and the severity of gastritis was evaluated according to Sydney criteria. RESULTS: H. pylori infection was found in 19 (63%) HD patients and in 22 (71%) control subjects. Gastric juice urea concentration was significantly higher in HD patients than in controls and H. pylori infection caused a significant decrease in urea concentration in both groups. There was an inverse correlation between urea and ammonia concentration in gastric juice in both groups. Ammonia concentration in both groups was higher in H. pylori infected patients. In H. pylori negative subjects ammonia/urea ratio was lower in HD patients in comparison to controls. Ammonia/urea ratio was raised by H. pylori infection in both groups, and the difference between HD and control groups persisted. H. pylori infection was associated with polymorphonuclear infiltration of gastric mucosa. There was a significant correlation between gastric ammonia and mucosal polymorphonuclear leukocytes infiltration and gastritis score. CONCLUSIONS: Higher urea levels in the gastric juice of chronically hemodialyzed patients do not seem to be a risk factor for infection with Helicobacter pylori.

Ammonia↗
PubMed2005

Nitrogen removal from sludge dewatering effluent through anaerobic ammonia oxidation process.

Anaerobic ammonia oxidation(Anammox) process is a novel and promising wastewater nitrogen removal process. The feasibility of transition of Anammox from denitrification and the performance of lab-scale Anammox biofilm reactor were investigated with sludge dewatering effluent. The results showed that Anammox process could be successfully started up after cultivation of denitrification biofilm and using it as inoculum. The transition of Anammox from denitrification was accomplished within 85 d. Anammox process was found suitable to remove ammonia from sludge dewatering effluent. The effluent ammonia concentration was detected to be 23.11 mgN/L at HRT of 28 h when influent ammonia concentration was fed 245 mgN/L, which was less than that for the national discharge standard II (25 mgN/L) of China. Volumetric total nitrogen loading rate was up to 584.99 mg TN/(L x d) at HRT of 17 h, while influent concentrations were kept 243.25 mg NH4(+) -N/L and 288.31 mg NO2(-) -N/L.

Ammonia↗