Progressive cerebellar and extrapyramidal motor disturbances in galactosaemic twins

Progressive cerebellar and extrapyramidal motor disturbances are described in two 16-year-old female twins with classical galctosaemia. The neurological disturbances, characterized by hyper- and dysmetric movements and bilateral intention tremor with choreatic, atactic and even ballistic motor storms, appeared at 12 years of age. Computerized tomography demonstrates cerebral atrophy in cerebellar, brain stem and basal ganglia structures. The central conduction times, determined by somatosensible evoked potentials, are grossly prolonged; the peripheral nerve conduction velocities are normal. The neurological sequelae described are considered a distinct entity in the course of galactosaemia.

First trimester diagnosis of Pompe's disease (glycogenosis type II) with normal outcome: assay of acid alpha-glucosidase in chorionic villous biopsy using antibodies

Prenatal diagnosis of glycogenosis type II was performed by direct assay of acid alpha-glucosidase (EC 3.2.1.20) in chorionic villous biopsy obtained by transcervical cannula aspiration from a pregnancy at risk in the 10th week of gestation. The exact value of the enzyme activity estimated by the use of antibody preparations for purified human liver acid alpha-glucosidase was in the heterozygous range, and so the homozygous enzyme deficiency could be excluded. The subsequent analysis of cells cultured from amniocentesis sampling in the 18th week of gestation resulted in a similar outcome. The study with antibodies showed that in 23 control chorionic villi obtained during gestational ages between 7-13 weeks, 1-15% of the total alpha-glucosidase activity at pH 4.0 were due to renal or neutral enzyme. This indicates that it may be important to employ antibodies for prenatal diagnosis using chorionic villous sampling. A healthy and unaffected boy was born. The biochemical values obtained from an umbilical blood specimen were in accordance with the results of the prenatal diagnosis.

Diagnosis of Pompe's disease using leukocyte preparations. Kinetic and immunological studies of 1,4-alpha-glucosidase in human fetal and adult tissues and cultured cells

Kinetic and immunological studies of 1,4-alpha-glucosidase show that the distribution of acid, renal and neutral alpha-glucosidase at pH 4.0 and 6.5 is as follows: in liver and cultured fibroblasts and amniotic fluid cells the activity at pH 4.0 is mainly due to the acid enzyme. Even at pH 6.5, the activity is largely due to the residual activity of the acid enzyme. In kidney and leukocytes, however, the activity by acid enzyme at pH 4.0 represents only 30-60% of the total activity and the remaining activity is from renal enzyme. At pH 6.5, the activity is almost exclusively of renal enzyme. Renal alpha-glucosidase has a higher affinity for maltose (Km, 0.8 mmol/l) than acid enzyme, however; for glycogen acid enzyme shows the highest affinity (20.7 g/l). There is no significant difference in the kinetic characteristics of alpha-glucosidase between fetal and adult tissues. In kidney, however, a relative increase in renal enzyme to acid enzyme with age is found, i.e. in fetal kidney the alpha-glucosidase activity at pH 4.0 is more than twice that at pH 6.5, whereas in adult kidney, the activity ratio at pH 4.0-6.5 is approximately 1. Antibodies for human liver acid alpha-glucosidase decrease the alpha-glucosidase activity in normal leukocytes by 22-75% at pH 4.0 (0.54-3.8 nmol/min per mg protein). The decrease is significantly lower in patients with Pompe's disease (0-0.11 nmol/min per mg protein) as well as in their parents and some siblings (0.15-0.70).

Inhibition of lens-aldose reductase activity by brazilin and haematoxylin

Brazilin and haematoxylin, plant pigments, were examined for their effects on the Bovine-Lens aldose reductase (LAR)-activity. About 50% inhibition was observed in a concentration of 10 (-4) M-brazilin and 10 (-4) M-haematoxylin, and above 95% inhibition was observed in a concentration of 10 (-3) M-brazilin and 10 (-3)M-haematoxylin. In order to determine the type of inhibition, kinetic studies were also conducted with brazilin and haematoxylin, in which both were found to be noncompetitive inhibitors.

Glycosylated haemoglobin and glycosylated albumin: evaluation of different methods in diabetic control

The levels of glycosylated haemoglobins and albumin were determined in 56 diabetic patients aged between 5 and 19 years. The glycohaemoglobin levels were measured by two different methods, cation-exchange chromatography and a colorimetric chemical method. The glycosylated albumin levels were measured by a chemical method in plasma albumin purified with Affi-gel Blue. The results were compared with other indicators such as blood glucose and urinary glucose. The postprandial blood glucose levels were well correlated with the levels of glycoproteins: glycohaemoglobin by the column method (r = 0.886), glycohaemoglobin by the chemical method (r = 0.72) and glycoalbumin (r = 0.662). The urinary levels of glucose showed a weak correlation with blood glucose levels (r = 0.214) and with glycoalbumin (r = 0.298), but no correlation with glycohaemoglobin. Significant correlations between the changes of glycosylated albumin levels and glycohaemoglobin were found (r = 0.78). The result of the comparison of the chemical method with the column method for glycohaemoglobin determination showed a high correlation between the values (r = 0.95). There were significant differences in glycosylated protein levels between normal and diabetics. There were also significant differences in glycohaemoglobin and glycoalbumin values between fairly managed and poorly managed groups of diabetics. Of the three parameters, glycoalbumin, glycohaemoglobin and plasma glucose, the greatest absolute changes were found in the levels of glycoalbumin.

A radioisotopic method for fructose-1-phosphate aldolase assay that facilitates diagnosis of hereditary fructose intolerance

A sensitive new method in which D-[U-14C]fructose-1-phosphate is used for fructose-bisphosphate aldolase (EC 2.1.2.13) assay is described. The radioactive fructose-1-phosphate compound was prepared from [U-14C]fructose by use of partly purified fructokinase (EC 2.7.1.4). With this method we measured normal values for aldolase in human liver (2.4-10.0 nmol/min per mg of protein), kidney (3.6-3.8), and intestine (4.2-10.0) as well as Km values for fructose-1-phosphate (approximately 1.0-2.2 mmol/L). In patients with hereditary fructose intolerance the aldolase activity in liver and intestine was less than 10% of normal values. The Lineweaver-Burk plots for data from patients with hereditary fructose intolerance were hyperbolic, indicating a structural alteration in the enzyme.

A radioisotopic method for fructose-1-phosphate aldolase assay that facilitates diagnosis of hereditary fructose intolerance

A sensitive new method in which D-[U-14C]fructose-1-phosphate is used for fructose-bisphosphate aldolase (EC 2.1.2.13) assay is described. The radioactive fructose-1-phosphate compound was prepared from [U-14C]fructose by use of partly purified fructokinase (EC 2.7.1.4). With this method we measured normal values for aldolase in human liver (2.4-10.0 nmol/min per mg of protein), kidney (3.6-3.8), and intestine (4.2-10.0) as well as Km values for fructose-1-phosphate (approximately 1.0-2.2 mmol/L). In patients with hereditary fructose intolerance the aldolase activity in liver and intestine was less than 10% of normal values. The Lineweaver-Burk plots for data from patients with hereditary fructose intolerance were hyperbolic, indicating a structural alteration in the enzyme.

Prenatal diagnosis of galactosemia and properties of galactose-1-phosphate uridyltransferase in erythrocytes of galactosemic variants as well as in human fetal and adult organs

The kinetic characteristics and isoelectrofocusing patterns of uridyltransferase and the concentrations of galactose-1-phosphate in hemolysates were investigated in a family with compound variants of Duarte and classical galactosemia. There were no significant differences in Km values between the genotypes. However, the isoelectrofocusing study with thin-layer polyacrylamide gels (PAGIF) as well as with agarose gels (AGIF) showed a distinctive difference. The enzyme from the Duarte variant resolved into at least two more activity bands at pH between 5.2 and 5.4. The accumulation of galactose-1-phosphate was observed only in homozygotes for classical galactosemia. Compound heterozygotes (G-D) without any clinical manifestations did not show an accumulation of galactose-1-phosphate. The isoelectrofocusing study of the enzyme in human tissues revealed their activity resolving into multiple bands, 6-8 bands at pH 5.50-6.00 and 1-3 bands at pH 4.9-5.2. No significant differences were found in the patterns between fetal and adult liver except that the intensity of the anodic bands (pH 4.9-5.2) was weaker in fetal tissues. Prenatal diagnosis of classical galactosemia was performed in nine families by measuring the enzyme activity in cultivated amniotic fluid cells. Absence of the enzyme activity in amniotic fluid cells was found in two cases, and in four cases the heterozygosity was diagnosed by a relative low enzyme activity, 30-50% of the activity in control cells cultured in parallel.

Parenteral nutrition with a "breast milk adapted" solution of amino acids in infants and children after abdominal surgery

Plasma amino acid levels as well as urinary and plasma concentrations of nitrogen were determined in 24 infants and 12 children on five consecutive days after major abdominal surgery. Parenteral nutrition was carried out by means of two different amino acid solutions. One formula (PE) was based on the amino acid composition of potato-egg protein, the other (BM) on that of human breast milk. Control subjects received glucose only. The controls showed decreased plasma levels of most amino acids as well as negative nitrogen balances. In contrast, in the patients treated with amino acids the plasma concentrations of most amino acids were found in the normal range. In the infants elevated plasma amino acid levels were found more often in the BM-group than in the PE-group. Among the children, however, the PE-group showed an elevation in the plasma levels of amino acids more frequently than the BM-group. There is no significant difference in the positive nitrogen balance between the BM-groups and the PE-groups. Therefore, it can be concluded that the use of BM has no clear advantage over that of PE.

The influence of folate antagonists on the metabolism of folic acid and its reduced derivatives in rat liver and kidney

Uptake and conversion of [3H]folic acid to polyglutamate derivatives by rat liver and kidney were inhibited by methotrexate or aminopterin (15 mg/kg body weight) and DL-tetrahydromethotrexate (30 mg/kg body weight). In contrast, these antagonists did not influence the conversion of L-5-formyl-[3H]tetrahydrofolic acid or L-5-methyl[3H]tetrahydrofolic acid to polyglutamine derivatives and had little effect on the uptake of reduced folate derivatives. When [3H]methotrexate, [3H]aminopterin, and DL-[3H]tetrahydromethotrexate were administered in small amounts (15 mug/kg body wieght), no metabolites of these compounds were observed. However, at higher doses of [3H]methotrexate (300 mug/kg body weight), more than 30% of the radioactivity remaining in the tissue 24 hr after administration could be attributed to a metabolite of methotrexate. This metabolite was tentatively identified as methotrexate diglutamate.

Subcellular localization of gamma-glutamyl carboxypeptidase and of folates

The subcellular distributions of glutamyl carboxypeptidase, folate specific activities, and radioactive metabolites of injected [3H] folic acid were studied in rat liver. The specific activity of glutamyl carboxypeptidase in the lysosomal fraction was near or greater than four times that in the other subcellular fractions. The specific activity of folates was highest in the soluble fraction (102 ng folate/mg protein) and lowest in the microsomal fraction (22 ng folate/mg protein). Nuclear, mitochondrial, and lysosomal folates were 95% folate polyglutamates, and microsomal and soluble folates were 85--90% folate polyglutamates. Injected [3H] folic acid was initially concentrated in the microsomal fraction, as measured by 3h cpm per ng folate. Initially, injected [3H] folic acid was found converted to folate penta- and hexaglutamates in all fractions to a similar extent except in the microsomes where the percentage conversion was much less, as measured by the percentage of total 3H cpm determined to be [3H] folate penta- and hexaglutamates. At 24 h, the conversion of [3H] folates to penta- and hexaglutamates in each fraction was less than that found for the endogenous folates. Injected [3H] folic acid after 2h was found to consist of 94% reduced folates in the soluble fraction, 56% in the mitochondrial, 55% in the nuclear, 20% in the lysosomal, and 15% in the microsomal fraction.

The availability of folates in man: effect of orange juice supplement on intestinal conjugase

The mechanisms of the low availability of endogenous folates in orange juice and the inhibitory effects on the availability of pteroylheptaglutamate (PteGlu7) caused by orange juice supplements were investigated in man by the use of simulated orange juice (containing the principal components: citric acid, malic acid, etc.) with several different pHs. The endogenous folates in orange juice were identified as mainly 5-methyl reduced derivatives of pteroylpolyglutamates (40-45% pentaglutamate, 10-15% tetraglutamate, 30-40% monoglutamate, and the rest were tri-and diglutamates). The availability of PteGlu7 is decreased to 54% by supplementation with 600 g concentrated orange juice (pH 3.7) and to 39% and 66% by the supplement of 24 g and 12 g citric acid (pH 3.7), respectively. Neutralization of 12 g citric acid to pH 6.4 largely reverses the inhibitory effect. On the other hand, the availability of pteroylmonoglutamate (PteGlu) is not influenced by a supplement of orange juice or citric acid. The results suggest that the low availability of PteGlu7 is due to the inhibition of intestinal conjugase caused by the low pH. These observations suggest that pH of foodstuffs may be an important factor in the absorption of polyglutamate forms of folate.