Ammonia infants

Nitrate and Nitrite. Nitrate is usually present in trace quantities in surface waters but occasionally occurs in high concentrations in some groundwaters. If present in excessive amounts, it can contribute to the illness infant methemoglobinemia. Nitrate is an essential nutrient for many photosynthetic autotrophs. Nitrite is an intermediate in the reduction of nitrate as well as in the oxidation of ammonia it is also used as a corrosion inhibitor in some industrial processes. 

The urea cycle is essential for the detoxification of ammonia 678 Urea cycle defects cause a variety of clinical syndromes, including a metabolic crisis in the newborn infant 679 Urea cycle defects sometimes result from the congenital absence of a transporter for an enzyme or amino acid involved in the urea cycle 680 Successful management of urea cycle defects involves a low-protein diet to minimize ammonia production as well as medications that enable the excretion of ammonia nitrogen in forms other than urea 680... 

Treatment of municipal water with chlorine and ammonia results in the formation of chloramines, a long-lasting disinfectant. Too much ammonia, however, enhances nitrification by bacteria in the water, which, in turn, increases the nitrate and nitrite levels. High nitrate and nitrite levels in drinking water is a health hazard, particularly for infants. 

For the determination of vitamin E in seed oils by HPLC, the oils can simply be dissolved in hexane and analyzed directly. Solid-food samples demand a more rigorous method of solvent extraction. In a modified Rose-Gottlieb method to extract vitamin E from infant formulas (86), dipotassium oxalate solution (35% w/v) was substituted for ammonia to avoid alkalizing the medium, and methyl tert-butyl ether was substituted for diethyl ether because of its stability against the formation of peroxides. 

The composition of air has undergone a remarkable change since the birth of our planet 4.6 billion years ago. The gases in the atmosphere of the infant earth were mostly methane, ammonia and water vapour. How different these ingredients are from those of the invisible dish you prepared ... 

Animal and human studies have shown that an elevated concentration of ammonia (hyperammonemia) exerts toxic effects on the central nervous system. There are several causes, both inherited and acquired, of hyperammonemia. The inherited deficiencies of urea cycle enzymes are the major cause of hyperammonemia in infants. The two major inherited disorders are those involving the metabolism of the dibasic amino acids lysine and ornithine and those involving the metabolism of organic acids, such as propionic acid, methylmalonic acid, isovaleric acid, and others (see Chapter 55). 

A second report (H4) concerned a female infant who was hospitalized at 20 days of age because of difficulty in feeding, lethargy, and convulsions. Two sibs had died with similar symptoms at 4 weeks of age, but two other sibs were normal. Blood ammonia levels on a relatively low protein intake (1.5 g/kg/day) ranged between 25 and 100 /ig/lOO ml, and blood urea between 2 and 14 mg/100 ml. Her general condition improved on the low protein diet, but later it deteriorated and she died at 7 2 months of age, weighing little more than her birth weight of 3.25 kg. Liver function tests were normal there was a slight metabolic alkalosis. 

A third instance has been briefly reported by Kirkman and Kiesel (KIO). They described a male infant who was admitted to hospital at 1 month of age because of vomiting, severe growth failure, and tremulousness. The blood ammonia was very high, 356 /j.g/100 ml. Neurological development was normal. Biochemical findings were an acidosis, organic aciduria, and lysinuria. There was also a moderate hyperglycinemia. When the protein intake was restricted to 1.5g/kg/day, the blood ammonia fell to 80-260 ig/100 ml. The liver biopsy obtained by needle aspiration showed a normal ornithine transcarbamylase activity which also had normal Km values. On the other hand, the carbamyl phosphate synthetase activity was only half that of specimens obtained at necropsy. 

In one infant with the fulminating variant of the disease the level of ammonia in the cerebrospinal fluid was 114 / g/100 ml when the blood level was over 800 /xg/100 ml (L5, L9) (Table 3). The only other reference to ammonia levels in cerebrospinal fluid or blood was by Carton et al. (C3), who observed in a neonate with argininosuccinic aciduria that the ammonia levels in both blood and cerebrospinal fluid as judged by column chromatography were high or very high. 

There are no studies that indicate that metabolism of ammonia differs between children and adults. Ammonia is eliminated from the body mainly by processing through the urea cycle in the liver, and urea is then eliminated in the urine and feces. The urea cycle is fully functional in infants at birth therefore, it is not expected that infants or children are at greater risk of hyperammonemia. Neurotoxicity resulting from h q)erammonemia involves alteration of levels of some components of the citric acid cycle, which leads to depletion of ATP, and starvation of brain cells, and depletion of glutamate, a precursor to the neurotransmitter y-aminobutyrate (GABA). It is not expected that children are more susceptible than adults to ATP depletion via this mechanism. 

Infants under 6 months of age may be more sensitive than adults to the effects of high levels of nitrates (from nitrification of ammonia in fertilizers) that may be present in groundwater and well water (Payne... 

In water, ammonia volatilizes to the atmosphere, is transformed to other nitrogenous compounds, or may be bound to materials in the water. Volatilization is highly pH-dependent, and can also depend on other factors such as temperature, wind speed, and atmospheric concentration. Transformation of ammonia in water occurs by the microbial processes of nitrification and denitrification. Nitrification yields nitrate and nitrite anions the former species can be responsible for methemoglobinemia in human infants if the contaminated water is ingested. Removal of ammonia from water can also occur by adsorption to sediments or to suspended organic material. 

Benyajati S, Goldstein L. 1975. Renal glutaminase adaptation and ammonia excretion in infant rats. 

In the severely ill infant, measurements of serum ammonia and lactate, urinary organic acids, urinary and serum amino acids and erythrocyle galacto.se I-phosphale uridyl transferase will be required. If the baby has a problem which is apparent intermittently, then blood and urine should be collected for analysis during the acute phase. 

The effects of ammonia on children are likely to be the same as for adults. We do not know if exposure to ammonia causes birth defects, or if it can pass to the fetus across the placenta or to infants via breast milk. 

However, encephalopathies with a metabohc basis tend to be the most problanatic for infants or children, with functional outcomes dependent upon timely and pradent interventions. Three varieties of metabolic encephalopathy in children are discussed here. The first two are closely related. Inborn (genetic) errors of metabolism can present in the newborn as severe encephalopathy from hyperammonemia alone. When a metabolic error presents months to years later, a degree of hepatic insufficiency may complicate the metabolic derangement. In acute or fulminant hepatic failure of any etiology (i.e., infections, drug-induced, toxin-related), the rise in serum ammonia may be only moderate but other factors contribute to the ensuing encephalopathy, which may be devastating within days. 

Due to concern of the recent changes to the status of the infant, additional labs including a metabolic panel and plasma ammonia are recommended immediately. These labs show the baby is extremely acidotic as well as hyperammonemic. The infant is airlifted to a children s hospital for tertiary care by the metabolic team. However, due to the extent of the acidosis and hyperammonemia as well as the prematurity, care is terminated. 

Camilla, a newborn female, was delivered in a forceps-assisted vaginal delivery after a normal pregnancy. The infant did well for the first 3 days of life, but began showing seizure-like activity. A CT scan showed a small trauma from the forceps-assisted birth including a small bleed and skull fracture. Laboratory studies obtained showed mild metabolic acidosis and mild hyperammonemia. The infant was transferred to the children s hospital for further tertiary care. Repeat plasma ammonia showed increasing hyperammonemia. 

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