Glutamine synthetase could be repressed several hundredfold rather than 6- to 10-fold as previously reported. Ammonia was not the primary repression signal for glutamine synthetase. Repression appeared to be mediated by a high level of glutamine and probably by a high ratio of glutamine to alpha-ketoglutarate. Mutations in glnA (the structural gene for glutamine synthetase) were seen to fall in...

Over the years schizophrenia become a challenging disorder in the understanding of its causes, course and treatment. The processes for the causes of neuropsychiatric disturbances in schizophrenia are still not completely known. Investigating metabolic changes in schizophrenia is important to capture valuable insights about mechanisms, progression, and diagnostic biomarkers. Priority of investig...

A method for the determination of plasma and whole blood ammonia is outlined which incorporates the desirable features of several older methods. By means of this method it has been demonstrated that the distribution of ammonia in erythrocytes and plasma of normal individuals is nearly equal to that of hydrogen ions. The ratio remains constant in cirrhosis, alkalemia, and ammonemia. It was obser...

Blood ammonia levels in patients with various liver diseases were determined quantitatively by a simple and rapid method using the Amitest Meter System. The results were compared to those obtained by an enzymatic method and were well correlated. This simple Amitest is also useful in animal experiments, particularly when there is a need to determine blood ammonia levels serially. This paper test...

Dairy barns are thought to emit large amounts of ammonia, which can have detrimental effects on human health and natural ecosystems. In the U.S., relatively little is known about the processes that affect the rate and magnitude of ammonia emissions from dairy barns. The end of a conventional tie-stall dairy barn was remodeled into four chambers (four animals per chamber) to initially evaluate d...

Background and aim: In acute liver failure (ALF), the brain is exposed to high levels of ammonia. Human studies defining the clinical significance of ammonia in ALF are lacking. This prospective study evaluated the relationship of arterial ammonia levels at admission to complications and survival among patients with ALF. Methods: Eighty consecutive ALF patients admitted from March 2001 to Decem...