Galactose tolerance tests

If the galactose tolerance test is used, it must obviously be applied with discretion. Glucose for intravenous administration and adrenaline for subcutaneous injection should be on hand. It is probably wiser not to carry out this test on young infants who may have galactosemia. 

Galactose tolerance tests have also been used in attempts to detect heterozygous carriers for galactosemia (D5, H6) this is dealt with in Section 5.3.1. Some heterozygotes are made ill by the galactose load (D3, H3, H16). Galactose tolerance tests have now been replaced, for this purpose, by the more specific and sensitive method of assay of enzyme activity. 

D5. Donnell, G. N., Bergren, W. R., and Roldan, M., Genetic studies in galactosemia. I. The oral galactose tolerance test and the heterozygous state. Pediatrics 24, 418-426 (1959). 

Stenstam, T., Peroral and intravenous galactose tolerance tests. Acta Med. Scand. Suppl. No. 177 (1946). 

Some cephalosporins non-competitively inhibited the active absorption of D-galactose by reducing the activity of Na/K-ATPase (211). Theoretically, this effect might interfere with galactose tolerance testing. 

DIO. Drill, V. A., and Ivy, A. O., Comparative value of bromsulphthalein, serum phosphatase, prothrombin time and intravenous galactose tolerance tests in detecting hepatic damage produced by carbon tetrachloride. J. Clin. Invest. 23, 209-216 (1944). 

The compensated stage does not usually display any signs of liver insufficiency (except possibly jaundice), nor are there any typical ailments. Functional parameters that can be quantified in routine laboratory tests (such as cholinesterase, albumin. Quick s value, bile acids) may still be normal or only minimally impaired in the individual instance. In contrast, liver tolerance tests (galactose, indocyanine green, etc.) demonstrate a reduction of liver function which is already quite considerable. 

By a disaccharide tolerance test. For instance if lactase deficiency is suspected, lactose is given orally. This should normally be broken down to glucose and galactose and the... 

A galactose or fructose tolerance test normally results in a rise in blood sugar levels as a result of their conversion in the liver by a series of enzymes including glucose-6-phosphatase. In Type I glycogen storage disease this does not occur. 

A test used in the investigation of intestinal lactase deficiency. It consists of the oral administration of lactose followed by the collection of blood samples in which glucose is measured. If intestinal lactase is present, the lactose is broken down to glucose and galactose which are then absorbed. The blood glucose level should therefore increase. However, this does not occur if there is a deficiency of lactase. A flat lactose tolerance test should, however, be followed by a glucose tolerance test in order to check that a generalized malabsorption does not exist. 

When studying the minimum structural requirements of an enzyme preparation from human blood, Hindsgaul and coworkers [77, 78] found that the enzyme tolerates only minor changes at the 6-position of the acceptor galactose. Although the relative transfer rates for the non-natural acceptors are far lower than for the parent compound, the enzyme may be applicable for the preparative synthesis of non-natural blood group B derivatives (cf. Fig. 7 and Table 5). Modifications at the fucose moiety have not been tested. 

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