[The occurrence of anti-Gm in bovine sera]. / Zum Auftreten von Anti-Gm in Rinderseren.

55 bovine sera were tested for the occurrence of "natural" anti-Gm-antibodies. All bovine sera agglutinated human 0Rh + erythrocytes coated with different anti-Rh-sera. On the other hand only seven bovine sera showed a haemagglutination inhibition by pooled human gamma-globulin. Specific anti-Glm(2) antibodies have been found in one of the seven sera.

ABH-secretion and Lewis red cell groups in diabetic and normal subjects from Ethiopia.

The possible relationship between Lewis red cell groups and secretor status and diabetes mellitus has been investigated in diabetic patients from Northwestern Ethiopia. The Lewis negative phenotype [Le(a-b-)] showed similar frequencies in diabetics and a control sample. Determination of the secretor status revealed a tendency to higher non-secretor rates in diabetics, particularly of the insulin-dependent type, in comparison with non-diabetic Ethiopians. A lack of effective immune protection from secretory IgA antibodies as a plausible explanation for the relationship between non-secretor status and IDDM is discussed. However, the available data from our study showed no statistically significant association between secretor state and IDDM. Without a detailed genetic characterization of our diabetic patients (HLA association data) it will be difficult to define precisely the postulated contribution of the Se gene to the aetiopathogenesis of IDDM.

[Population genetic studies in Ethiopia: distribution of blood group polymorphisms in Amhara/Tigrai ethnic groups]. / Populationsgenetische Studien in Athiopien: Die Verteilung von Blutgruppenpolymorphismen in den Amhara/Tigrai-Ethnien.

During 1981-1982 and 1983-1984 a population-genetic study has been performed in the Amhara/Tigrai ethnic groups of Northwestern Ethiopia (Gondar). Blood group frequencies are reported for 6 systems (AB0, MNSs, Rh, P, Kell, Kidd), secretor status, haptoglobin, Gc, Gm/Km, HLA-A and -B as well as for the erythrocytic enzyme polymorphisms AcP, PGM1, ADA, EsD, GPT, AK and GLO I. The results are compared with other reports from East Africa and the Arabian peninsula. The mixed caucasoid-negroid gene pool of the Amhara/Tigrai as well as their relations with Arabia are confirmed.

[Genetic factors in anti-D-antibody formation]. / Genetische Faktoren bei der Anti-D-Antikörperbildung.

The blood group specific artificial immunization for producing anti-D-antibodies in Rh-negative persons ("de-novo immunization") is scarcely successful at present and involves risks of health for test persons. With the justified suggestion that the antibody development is genetically influenced even in man, those serological features were being searched for which might reveal a good anti-D-formation, viz. AB0-blood group, HLA antigens and serum groups Hp, Gm and Km. 134 men de-novo immunized were examined. In those persons forming anti-D with a high titre ("high responders") blood group A will be encountered more frequently. Blood group B will frequently occur in "non-responders". In 78 test persons examined in the HLA system was no correlation between the features of the HLA system and the formation of anti-D. The serum features investigated in 71 test persons did not allow any correlation to anti-D formation to be recognized in the Hp, Gm and Km system. It seems reasonable to continue the investigation for relationships between antibody development and certain hereditary characteristics in the human blood, including HLA-DR gene place.

[The importance of serogenetics as a subspecialty of human genetics]. / Die Bedeutung der Serogenetik als Teilgebiet der Humangenetik.

Survey of development, positions and aspects of some of the most important fields of blood group genetics: serogenetic individuality of human blood, formal genetics, blood groups and diseases, linkage and localization on chromosomes, evolution.

[Effect of oxygen partial pressure on citric acid synthesis in Saccharomycopsis lipolytica using n-alkanes]. / Einflusseta des Sauerstoffpartialdrucks durch Saccharomycopsis liplytica aus n-Paraffinen.

The dependence of growth formation of citric acids (citrate: isocitrate = 1:1) on oxygen parital pressure of an alkane utilising yeast Saccharomycopsis lipolytica was investigated. During growth oxygen corresponds to a Michaelis-Menten-kinetics (Ks = 2.0 . 10(-5) M). The respiration quotient RQ for a dissolved oxygen concentration in the range of 10-100% (air saturation) is 0.46 +/- +/- 0.04. The phase of product formation is characterized by 3 sections. Immediately after N-exhaustion the cell activities are the highest. They decline during the first 30 hours of production. Besides the production of reserve material in this first section the highest production rate for citrate and isocitrate is observed. The rate of citric acid production depends on the oxygen partial pressure and is governed by Michaelis-Menten-kinetics. The specific production rate and the rate of oxygen consumption correspond to KS-values of 4.0 X 10(-5) and 3.3 X 10(-5) M, respectively. The RQ-value declines to a constant value of 0.23 +/- 0.02 and is not influenced by oxygen partial pressures in the range of 10--100% (related to air saturation). During the second section cell activities remain nearly constant for about 100 h. Due to this constancy the following equation could be derived: 14 O2 + C15H32 leads to 2 C6H8O7 + 3 CO2 + 8 H2O. In the third section the cell activities decline again.

[Haptoglobin-Johnson-type and evident ahaptoglobinemia in 2 families]. / Haptoglobin-Johnson-Typ und scheinbare Ahaptoglobinämie in zwei Familien

In two Leipzig families mark carriers of the rare Hp-Johnsontype as well as apparantly genetically associated with this hypohaptoglobinaemias were observed. Demonstration of the Hp-patterns of these mark carriers and comparison with standard Hp-patterns with the help of several methods (starch gel electrophoresis, agar gel diffusion test, immunoelectrophoresis). Short survey of the modern conception for the explanation of the genetic regulation of the Johnson-type.