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In a random population sample in Berlin (West) the following Ut-frequencies were found: Ut1 0.938; Ut2 0.062. This is consistent with other results obtained in German populations.

Adenylylating or acetylating enzymes, which are produced by grampositive and gramnegative bacteria resistant to aminoglycoside antibiotics, are useful tools in determining concentrations of aminoglycosides in patients' body fluids. Due to their accuracy, stability, versatility, fastness and inexpensiveness, enzymatic assays are the tests of choice for the routine determination of aminoglycoside concentrations.

In a preceding paper the genetics of resistance of 2 representative strains exhibiting resistance to beta-lactam antibiotics (ampicillin, catbenicillin, cephalothin) to aminoglycosides (kanamycin, neomycin, paromomycin, gentamycin, sisomycin, tobramycin, streptomycin, spectinomycin) and further antimicrobials (tetracycline, chloramphenicol, suphonamides) were described. This paper reports about the mechanism of resistance to beta-lactam antibiotics and aminoglycosides in these strains. Enzymatic extracts from K. pneumoniae 1 and Serratia marcescens 2 were produced by the osmotic shock procedure. Incubation of these extracts with aminoglycoside antibiotics, to which the strains are resistant, and ATP resulted in the total inactivation of the antimicrobials, as measured with a Bacillus subtilis assay. Analysis of this inactivation with the radioactive methods of Davies and his colleagues revealed that the kanamycins, neomycins, paromomycin and gentamycin A were phosphorylated. Because butirosin was not a substrate for the phosphorylating enzyme, it was concluded that the strain produced the neomycin/kanamycin phosphototransferase I. Furthermore, it was found that streptomycin and spectinomycin were adenylylated by the enzymatic extracts as well as gentamycin C1a, C1, C2, A, tobramycin, sisomycin and the kanamycins. This substrate profile indicated the presence of two adenylylating enzymes: streptomycin/spectinomycin-adenylyl-transferase and gentamycin-adenylyltransferase. After transfer of multiple drug resistance by conjugation from both strains into C. coli K-12, sonified extracts were prepared and examined for enzymatic activity splitting beta-lactam antibiotics. The relative rates of inactivation of benzylpenicillin, ampicillin and cephaloridine as well as the inhibitory effect of cloxacillin, but not of p-chloro-mercuri-benzoate on the inactivation of cephaloridine indicated that both strains produced a class III/type a (TEM type) beta-lactamase. It is discussed that the increasing frequency of gram-negative organisms form the university hospital with identical resistant phenotypes as the strains examined is the result of the spread of an R-factor among the hospital bacterial flora.

The mother of a boy who suffered from classical galactosaemia (galactose-1-phosphate uridyl transferase deficiency) has unilateral cataracta. In addition the boy had a decreased activity of the UDP-galactose-4-epimerase. The latter defect could also be demonstrated in the erythrocytes from the mother and the grandmother. In contrast to the finding of cataracta in the mother the grandmother with the same type of double heterozygosity was ophthalmologically normal. The implication of partial maternal disorders of galactose metabolism will be discussed in view of their possible role for the origin of cataracta.

The two enzymes of galactose metabolism, namely galactokinase and galactose-1-phosphate uridyltransferase (Gal-1-PUT), were measured in 3653 subjects aged 7 months to 84 years in der to obtain the incidence of the gene deficiency causing galactosaemia in the Western Hungarian province of Vas. To date nothing is known about these frequencies in this particular region. It was of special interest whether these enzyme defects are to be found more frequently in gypsies than in a comparable population of West Hungary. The frequency of homozygous Gal-1-PUT deficiency amounts to 1:23,500; the respective incidence of galactokinase deficiency is 1:64,000. Both enzyme deficiencies in this province are not higher than in other countries. Considerable differences were established in the gene frequencies in individual areas and for various groups of subjects with variations from 1:30,000 to 1: 127,000 for galactokinase deficiency and from 1:5,300 to 1:81,000 for Gal-1-PUT deficiency. Neither gene deficiency occurred more frequently in gypsies than in the general population. This study demonstrates that the results of such analyses are relevant only to the investigated region and the greatest possible number of subjects must be taken in order to draw reliable conclusions.

A basic issue of biomembranes is their ability to facilitate specific transport of selected molecules. This transport is catalyzed by carriers which are membrane proteins and form, analogous to enzymes, carrier-substrate complexes. The ADP, ATP carrier of mitochondria is highly suitable for elucidating the mechanism of this catalysis due to its unique qualities such as great abundance in higher cells, easy isolation in native state by detergents, existence of inhibitors specific for either the in- or outward looking binding site and direct observation of a carrier-substrate complex. As central catalytic steps, the reorientation of the substrate-binding site at the carrier during translocation across the membrane could be demonstrated at the intact membrane and the isolated protein. The results are interpreted by the gated-pore mechanism where two subunits form a gate with a central binding site which radically change conformation and specificity on transition from one to the other side of the membrane.

We investigated the genetic polymorphism of galactose-1-phosphate-uridyl-transferase (Gt) of 525 blood samples from Southern Germany. The gene frequencies of Gt1 are 0.9581 and of Gt2 0.0623. Comparing the gene frequencies of galactosemia (0.006), GtD (0.06), Gt1 (0.9581) and Gt2 (0.0623), we see that the gene frequencies of GtD and Gt2 are nearly identical. In expert opinions that Gt is a system of insufficient information.

In the past, galactosemis was considered to be one disorder; today it is subdivided into various enzymopathies. The enzymopathy occuring most frequently is the disorder with galactose-i-phosphaturidyl transferase. The morphologic equivalent of this desease was described on the basis of two letal cases involving siblings. The parents and the third child in this family (born 6 years later) showed only a 50% reduction in galactose-1-phosphaturidyltransferease activity in the erythrocytes. This was a heterozygous form of glactosemia without manifestations.

Three inborn errors of galactose metabolism as known today. Only two of them cause illness: the deficiencies of galactokinase and of galactose-l-phosphate uridyltransferase. Both can be detected through mass screening of newborns and are amenable to a simple and successful dietary treatment. Mass screening of newborns for disorders of galactose metabolism can be performed efficiently and inexpensively if it is incorporated in the general newborn screening program.