Metabolic disorder, definition

Because C02 is a volatile acid, it can rapidly be changed by the respiratory system. If a respiratory acid-base disturbance is present for minutes to hours it is considered an acute disorder while if it is present for days or longer it is considered a chronic disorder. By definition, the metabolic machinery that regulates HC03 results in slow changes in serum bicarbonate and all metabolic disorders are chronic. This means that there are six simple acid-base disorders as outlined in Table 25-1.2... 

Indications for the transplantation of hepatocytes predominantly involve those liver diseases in which functional failures occur in the liver cells (not in the bile ducts). Permanent transplantation would be indicated, for example, in order to eliminate congenital metabolic disorders of the liver cells. In this case, hepatocytes from the patient could be used, with subsequent elimination of the defect by gene technology, as well as hepatocytes from healthy donors. A few years ago, a therapeutic effect lasting for over one year was achieved for the first time in a girl suffering from the Crigler-Najjar syndrome (I. X Fox et af, 1998). Human hepatocytes are most definitely more suitable than animal liver cells. The latter may well meet the requirements for a provisional substitute, but not for permanent transplantation. 

Narins RG. Acid-base disorders Definitions and introductory concepts. In Narins RG, ed. Maxwell Kleeman s Clinical Disorders of Fluid and Electrolyte Metabolism, 5th ed. New York, McGraw-Hill, 1994 765—768. 

Tubular acidosis is primary (an isolated inherited metabolic disorder) or secondary (a metabolic disorder associated with inherited or acquired lesions). It is characterized by the inability to maintain normal blood pH as a result of interference with bicarbonate reabsorption or a defect in renal hydrogen excretion. By definition, glomerular filtration is not altered in renal tubular acidosis. 

Amino acids can be separated without prior derivatization on a cation-exchange resin column. The elution buffers are classically lithium citrate buffers with different pH values and salt concentrations, which are applied stepwise. There is usually a programmed increase in column temperature. Consequently, there are numerous variables affecting the separation of the individual amino acids [6]. For the detection of the amino acids, the column effluent is mixed with the ninhydrin reagent. Nowadays there are only very few manufacturers of AAAs left. The considerable cost of purchase and the operation costs are a potential threat to the widespread application of this technique, although it is still considered to be the definitive method for diagnosing disorders of amino acid metabolism. 

The disease is a rare inherited disorder characterized by a progressive degeneration of the lenticular nucleus in the brain and by cirrhosis of the liver. Barbeau et al. (Bl) studied a case of Wilson s disease which presented normal ceruloplasmin and serum copper values but increased excretion of kynurenine, 3-hydroxykynurenine, and conjugated anthra-nilic acid in xurine after an oral dose of 2 g L-tryptophan. This defect in tryptophan metabolism could be related to that of other amino acids and to the actual content of ceruloplasmin in Wilson s disease (Bl). These findings corroborated Marver s (M2) investigations demonstrating a definite excretion of kynurenine and 3-hydroxykynurenine in abnormal proportions after a tryptophan load in a case of Wilson s disease. 

Xanthinuria is a rare hereditary disease characterized by a deficiency of xanthine oxidase (E C 1,2,3,2), which metabolized hypoxanthine and xanthine to uric acid. In Japan, two cases of xanthinuria have been reported. However, during the past two years, we have investigated four patients with hypouricemia, hypouricosuria and xanthinuria. In almost all of these patients, hypouricemia (less than 1,0 mg/dl) was the most important index information to make a definite diagnosis of this disorder. After clinical profiles of these four patients were described, an easy method of detection of xanthine oxidase activity from the duodenal mucosa was developed by the authors. Urinary oxypurine was also analyzed by high-pressure liquid chromatography, and the results are reported here. 

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