13C-ethanol and 13C-acetate breath tests in normal and aldehyde dehydrogenase deficient individuals

Four normal and five aldehyde dehydrogenase (ALDH) isozyme I deficient individuals were subsequently loaded with (1-13C)ethanol and (1-13C)sodium acetate and the conversion of the label to 13CO2 was determined in expired air by isotope ratio mass spectrometry. In the 13C-acetate breath test, both groups showed virtually identical recovery of the label in expired air, namely 48.5 +/- 2.3% (mean +/- S.D.) for normal and 46.8 +/- 5.7% for deficient individuals. However, in the 13C-ethanol breath test, both the groups performed differently. On average, although a certain overlap of the single data was observed, the recovery of the label after four hours was 43.4 +/- 3.8% for the normal and 35.6 +/- 6.8% for the ALDH deficient subjects. These findings suggest a slower conversion of ethanol to carbon dioxide in aldehyde dehydrogenase deficient individuals, which may be another consequence of this deficiency besides the higher plasma acetaldehyde levels observed after ethanol loading in comparison to individuals with normal aldehyde dehydrogenase activity.     

δ-aminolevulinic acid dehydrase (porphobilinogen synthase) in two families with inherited enzyme deficiency

The inheritance of a deficient delta-aminolevulinic acid dehydrase (ALA-D; synonym: porphobilinogen synthase; EC 4.2.1.24) was studied in blood samples of two families over three generations. The propositus in each family was a young male acute hepatic porphyria patient with an almost complete ALA-D deficiency in the homozygous state (ALA-D activity less than 2% of controls). Heterozygotes are clinically non-affected (mean ALA-D 36% of controls). The mode of transmission could be traced by enzyme activity and electrophoretic polymorphism studies. Heterozygotes are detected by the demonstration of enzyme activity in the gel. The notation D was used for the gene expressing the defective enzyme. The "phenotype" D-1 was observed in six, the "phenotype" D-2 in three of all heterozygotes studied. These results are compatible with a single normal allele in heterozygotes responsible for enzyme activity. Quantitative assays and the segregation pattern in both families suggest a 3-allele-system for the inheritance of ALA-D deficiency.     

Heterogeneity in maple syrup urine disease: Aspects of cofactor requirement and complementation in cultured fibroblasts

Fibroblast strains derived from six patients with maple syrup urine disease have been investigated for their requirements of the cofactors NAD, CoASH, Mg⁺⁺ and TPP in comparison with 10 normal control strains. The reconstitution of the decarboxylase function of branched chain α-keto acid (BCKA) dehydrogenase complex in lysed cells was studied with respect to the substrates u-keto-isocaproic acid, α-keto-isovaleric acid, and α-keto-β-methylvaleric acid (KIC, KIVA, MEVA). The enzyme activity of all normal control strains for the substrates KIC and KIVA was not reconstituted by TPP + Mg⁺⁺ alone, but CoASH + NAD could reconstitute the enzyme activity with KIC and KIVA in different degrees. Only two control strains were tested with MEVA as substrate, and these showed in contrast that TPP + Mg⁺⁺ could partly reconstitute the enzyme activity. In contrast to the relative homogeneiy in the reconstitution profiles of normal strains, the five classical and one intermittent MSUD strains showed heterogeneity in cofactor requirements.
Complementation analysis using heterokaryons prepared from fibroblasts of four patients with classical MSUD and one patient with intermittent MSUD showed, in contrast to experiments with normal controls, a partial amelioration of the defect in two combinations; it is suggested that the defect in these strains is located at different functional subunits of the multienzyme complex.     

Alkylierung von Nicotinsäureamid und Nicotinsäure durch Tetramin (1-Aziridino-2-hydroxy-buten-3) und andere carcinostatische Äthylenimin-Verbindungen

Zusammenfassung Die Alkylierung von Nicotinsäureamid, Nicotinsäure und einigen anderen biologisch wichtigen Substanzen durch verschiedene Äthylenimin- und N-Lost-Verbindungen wurde studiert.Methoden zur quantitativen Messung der Alkylierung sowie die Synthese der Alkylierungsprodukte von Nicotinsäureamid und Nicotinsäure mit der Äthylenimin-Verbindung Tetramin werden beschrieben.Es wird gezeigt, daß die Alkylierung von Nicotinsäureamid und Nicotinsäure nicht am carcinostatischen Wirkungsmechanismus von Tetramin beteiligt ist.

---

Summary The alkylation of nicotinamide, nicotinic acid and other biologically important substances by different ethyleneimine-compounds and N-mustards was studied.Methods for the quantitative measurement of the alkylation and the synthesis of the products of alkylation of nicotinamide und nicotinic acid by the ethyleneimine compound tetramine are described.It is shown that the alkylation of nicotinamide and nicotinic acid is not involved in the carcinostatic mechanism of tetramine.

---

---

Mit 7 Textabbildungen

---

Ein wesentlicher Teil der vorliegenden Arbeit ist der Dissertation von Wolfgang Duntze an der Medizinischen Fakultät der Universität Freiburg i. Br. entnommen.     

Activity of the creatine kinase isoenzyme CK-BB in the serum of neonates as an indicator of perinatal damage to the central nervous system

By means of the immunoprecipitation method significantly higher activities of creatine kinase BB isoenzyme were measured in the sera of neonates with CNS symptoms than in the sera of healthy or sick neonates without CNS symptoms. The activity of CK-BB inversely correlated with the one-minute Apgar score. These results suggest a leakage of CK-BB from the damaged CNS tissue into the blood circulation. Determination of CK-BB might be helpful in the assessment of perinatal brain damage.     

Linkage studies between HL-A and GPT polymorphisms and other genetic markers.

The phenotypes of 56 families with 126 children from the Hamburg area as well as gene frequencies and segregation of the genetic markers GPT, AP, ADA, AK, PGM1, PGM3, 6-PGD, CHE, C3, Gc, Tf, Hp and Cp were studied. In regard to linkage, the informative families were correlated to the results of HL-A and GPT typing. The linkage was tested according to the sequential test by MORTON (1955). See article. For other gene loci, linkage to the HL-A or GPT system could not be proved. But the positive lod scores of HL-A/GPT, HL-A/AP and GPT/6-PGD may give indication for linkage.     

Human aldehyde dehydrogenases: their role in alcoholism

This article surveys the state of our knowledge concerning the biochemical and genetic variations in aldehyde dehydrogenases (ALDHs) in humans and their role in alcohol sensitivity, alcohol drinking habits, and alcoholism. Variations in acetaldehyde metabolism via genetically determined polymorphisms in ALDH enzymes seem to play an important role in individual and racial differences in acute and chronic effects of alcohol drinking as well as towards vulnerability to organ damage after chronic alcohol abuse. Alcohol sensitivity and associated discomfort symptoms accompanying alcohol ingestion may be determinantal for the significantly low incidence of alcoholism among Japanese, Chinese and other Orientals of Mongoloid origin. An abnormal ALDH isozyme has been found to be widely prevalent among individuals of Mongoloid race, and is mainly responsible for the acute sensitivity to alcohol commonly observed in this race. Persons sensitive to alcohol by virtue of their genetically controlled ALDH isozyme deficiency may be discouraged from drinking large amounts of alcohol in their daily life due to the initial adverse reaction experienced after drinking alcohol, and thus are protected against alcoholism.     

Studies on the change of electrophoretic mobility and the decay of catalytic activity of brain-type creatine kinase isoenzyme (CK-BB) following incubation at 37 °C

Incubation of CK-BB in serum (1:3, v/v) at 37°C for 3 h caused a change of its electrophoretic mobility and decay of its catalytic activity. Similar effects were observed following incubation in water. Incubation in saline somehow preserved the electrophoretic mobility but not the catalytic activity. No effect was noted when incubated at 4°C for 3 h. Further study on the rate of decay revealed that the decay in albumin solution (1:50, v/v) is quite similar to that in serum. More dramatic decay was noted when incubated in water and less when incubated in saline. It was further shown that the higher the incubation temperature (4°C, 25°C or 37°C) the faster the decay. The rate of decay of CK-MM was much slower in all conditions of incubation. Determination of isoenzyme activities by means of an immunoprecipitation method again demonstrated that CK-BB lost a great deal of its catalytic activity following incubation at 37°C for 1 h, and hence falsification of the isoenzyme pattern.     

Hereditary ataxia and the sixth chromosome

Possible linkage of the gene or genes for dominant hereditary ataxia and three genetic markers on the short arm of the sixth chromosome (HLA, properdin factor B [Bf], and glyoxalase I) was investigated in five families. Logarithmic odds (lod scores) were calculated for the linkages and found to be either inconclusive or in favor of nonlinkage. Caution is advised in the summing of lod scores for separate families because of the wide spectrum of clinical and anatomical manifestations of dominant hereditary ataxia. Three families with recessive hereditary ataxia were also studied. Identical haplotypes occurred in affected and unaffected siblings. It did not appear likely that the recessive genes of the parents were transmitted in linkage with the markers on the short arm of the sixth chromosome.