Ornithine transcarbamylase is a highly conserved enzyme in arginine biosynthesis and the urea cycle. In Xanthomonas campestris, the protein annotated as ornithine transcarbamylase, and encoded by the argF gene, is unable to synthesize citrulline directly from ornithine. We cloned and overexpressed this X. campestris gene in Escherichia coli and show that it catalyzes the formation of N-acetyl-L...

In this brief review, I will give an account of what has happened in the field of liver transplantation in the last 32 years and comment on the prospects for the transplantation of gastrointestinal organs, to be specific, of the intestines. Case Report Liver replacement always has been the most interesting of the transplant procedures. Let me start by illustrating with a case report what a powe...

Remarkable improvements in public health, nutrition, hygiene, and availability of medical services in the last 20 years have significantly reduced infant and childhood mortality in Thailand. Therefore, many rare and previously unidentified genetic disorders, which, in the past, usually led to the death of affected infants before a definitive diagnosis, have now been increasingly recognized. Rec...

Wood frogs (Rana sylvatica) can accumulate substantial amounts of urea during fall and winter. In this study, maximal urea production capacity was examined in R. sylvatica collected at various times of the year and in response to experimental hyperuremia and dehydration. Activity and expression of carbamoyl phosphate synthetase I (CPS I), the hepatic regulatory enzyme of the urea cycle, were us...

Ornithine transcarbamylase (OTCase, EC 2.1.3.3) a mitochondrial enzyme of the urea cycle catalyses the formation of citrulline from ornithine and carbamoyl phosphate. It has been purified from liver in 3 mammalian species: bovine [ 11, human [2] and rat [3,4] but not from mouse. We decided to purify mouse OTCase because the mouse is the only mammalian species in which two strains with an OTCase...

We report the case of a newborn baby with carbamoyl phosphate synthetase deficiency. He presented at 2 weeks of life, deteriorating to a state of hyperammonaemic coma and respiratory failure. Rapid detoxification was successfully achieved by continuous venovenous haemofiltration while a definitive diagnosis and treatment were determined. The ammonia clearance achieved by continuous venovenous h...

Arginase, a manganese-dependent enzyme that widely distributed in almost all creatures, is a urea cycle enzyme that catalyzes the hydrolysis of L-arginine to generate L-ornithine and urea. Compared with the well-studied arginases from animals and yeast, only a few eubacterial arginases have been characterized, such as those from H. pylori and B. anthracis. However, these enzymes used for argina...

Two newborn infants, male (A) and female (B), with lethal hyperammonaemia are described in the same family. In both, symptoms started on the second day of life. Lethargy and hypotonia were the most prominent initial findings and were followed by convulsions and coma. In both, blood ammonia levels rose to 570 mumol/u (795 microgram/100 ml) a few hours before death, which occurred on the third an...

A fatal case associated with severe hyperammonaemia is described in which no urea cycle enzyme deficiency could be found. This prompted further investigation of blood ammonia levels in neonates admitted to the premature baby unit at Hammersmith Hospital. 102 specimens were taken from 42 babies within the first 3 weeks of life; the babies had a variety of clinical conditions. The mean ammonia le...

Catabolism is a serious clinical problem in patients with active inflammation. Under such stressful conditions, the catabolism and loss of tissue nitrogen (N) result from proteolysis and are augmented by an up-regulation of the hepatic capacity to eliminate amino-N via urea-N. Our earlier studies suggest that this is part of the acute phase response to inflammation despite the increased need fo...