Biomedical subjects
Publications and source records attributed to K Hummel.
33 different adamntyl amidines containing four different structural types were synthesized and checked for virostatic activity. The activity of compounds of type II seems to originate in their ability to form H-bonds. The strength of antiviral activity is at least partly determined by the electronic effects of substituents at the benzene ring.
Frequencies for the genetic polymorphisms of the serum proteins Hp, Tf, Gc, Gm, Inv and Pt are presented for 7 ethnically defined Negroid sub-samples (total n = 918--977, depending on genetic marker system) from South Africa. The results are discussed in terms of previous findings and of factors assumed to have an influence on the distribution of the particular genetic markers. The present report on the Pt ("post transferrin" approximately C3) polymorphism represents the first report on the genetic variation of the corresponding beta1A-globulin fraction within African Negroids (PtA = 0.009, PtB = 0.966, PtC = 0.025).
Investigating a paternity case we observed a pretended opposite homozygosity of the S and s alleles between a mother and her child. The presence of the rare allele Su in this family could be demonstrated with the aid of dosage studies and blood group testing of the mother's parents. 22 additional genetic marker systems, including the HLA-system were examined, a biostatistical calculation was performed as well. The results obtained from these testings were in accordance with the hereditary rules and the posssibility of ilegitimacy or of children's substitution could be excluded. Only Caucasoid ancestry was known to the family. In addition, family members showed another rare blood group marker, the allele GPT0.
In a case of disputed paternity genetic incompatibility was observed in the ABO blood group system between mother (O) and child (AB). From biostatistical evaluation of 21 genetic markers, including HLA phenotypes, a high value of probability for paternity, maternity and parentage was found between the child, the child's mother, the accused man and his mother. Substitution of the newborn was thereby excluded. The serostatistical evaluation of maternity and paternity could be supported by anthropological opinion. In serological investigations of the ABH system the A and B antigens of the 'A2B' cells were found to be abnormal in the child, the child's father, and the father's mother: the A was weaker than normal A1 but stronger than normal A2; the B was found to be abnormal which in addition was documented through occurrence of irregular anti-B antibodies in the child. In comparison to normal controls (A1, A2, B, A1B, A2B) diminished activity of alpha-D-N-acetylgalactosamine and alpha-D-galactosyltransferase were observed in the three 'A2B' propositi. These facts confirmed the existence of a cis-AB gene in the Lam. family which the child inherited from her father and the child's father from his mother. Assuming a population frequency of 1.1 X 10(-5) for the cis-AB gene, the probability for paternity was calculated from all genetic markers to be W = 99.9999985%.
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The assumption that immune and normal alloantibodies of the ABO system could be distinguished by partial neutralization with soluble specific blood group substance (Witebsky test) has been reexamined. The following results were presented: 1. ABO alloantibodies in both normal and immune sera as well as their IgG and IgM preparations were inhibited by their homologous soluble specific blood group substances. 2. Anti-A and anti-B immune antibodies as well as normal antibodies of the IgG class were found to be strong hemagglutinins in a saline medium; therefore they have to be called "complete" hemagglutinins as have anti-A and anti-B antibodies of the class IgM too. 3. ABO alloantibodies in both IgG and IgM preparations were able to form precipitation pellets with their homologous soluble specific blood group substances. IgM revealed a stronger precipitation power as IgG. 4. Agglutination reaction in saline was inhibited by the 50-200-fold group substance concentration needed for a optimal precipitation reaction, whereas agglutination of enzyme treated erythrocytes or red cells tested with antiglobulin (Coombs) sera was inhibited by a 20,000-80,000-fold concentration of the blood group substances. 5. Soluble antigen-antibody complexes, prepared from solubilized precipitates or from Witebsky test mixtures using chromatography, ultracentrifuge or ultrafiltration for separation were able to agglutinate erythrocytes in the antiglobulin or papain test. Following conclusions were drawn: A. Soluble antigen-antibody complexes are the main component leading to a positive Witebsky test. B. The mechanism of the Witebsky test as it has to be assumed in respect to our findings do not allow the distinguish immune and normal alloantibodies resp. IgG and IgM alloagglutinins in the ABO system.
Formulas for the computation of the Y/X likelihood ratio will be given when in view of a biostatistical evaluation of blood group findings frequencies other than Central European ones should be used for all participants concerned. The given formulas are applicable to all common blood group systems and factors currently used in blood group expertises, except the Rh and HL-A systems which are too complex for simple arithmetic formulas.
A previously described computer programme designed to include any given relatives was modified to such an extent that also the plausibility of paternity with blood group findings can be computed for cases involving aliens.
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The article gives a review of the legal situation of the illegitimate child in the GFR and of the principles in the statement or refutation of paternity. The directives, valid for the blood group expertise on parentage and the biostatistical evaluation of blood group results are discussed. Finally a survey of the value of a positive or negative biostatistical hint for paternity is given.
Blood group systems with a rare second allel are in praxis ineffective and therefore uneconomical because of their low exclusion potency as well as their low serostatistical value. The evidence of exclusion in particular blood group systems is fixed by the German "Richtlinien". With the new German law, however, one has to differentiate between the requirements in respect of the "offenbar unmöglich" ("fatherhood evidently impossible") in cases of extramatriomonial children, and those in respect of "schwerwiegende Zweifel" ("serious doubts in fatherhood") in cases of illegitimate children. The serostatistical results can give an indication on non-fatherhood, but in no case a real exclusion of paternity. Further evidence, as an anthropological or an HL-A expert opinion, is necessary to decide if the negative hint is reliable or not. To evaluate blood group (and HL-A) findings biostatistically, one uses the BAYES' Theorem with ESSEN-MOLLER's frequencies X and Y (in two-hypothesis cases). As prior plausibility one sets ESSEN-MOLLER's normative 0.5 or a realistic value, calculated from a concrete material of forensic cases. Statistical values on the basis of the exclusion chance as A, WA, Z, P and x do not give the whole information, because the phenotype of the man is not (or not fully) regarded. Therefore these values are of no use in serostatistical evaluation. With appropriate frequencies it is possible to calculate the probability of paternity also in cases in which foreign people is involved. If foreign frequencies are not available, the German "Richtlinien" allow to use european frequencies, if the involved people shares the caucasoid (europid) race.
In 129 two-children cases, including 84 twin cases and 45 brother and sister cases, the probability of paternity of one or several men was calculated, applying the method of Hummel and Schulte-Mönting. With this method the whole information, given by the blood group results, is used. Because of this, the achieved values of probability in most of the cases are higher than the values achieved using the Essen-Möller formula, in which the relation between the children is not taken into account.
A calculation program is described by means of which the frequency of any type of relationship in cases of disputable descent (questionable partenity, maternity, parenthood, brother- and sisterhood) using blood group results, can be calculated. Within the scope of forensical practice, the program is above all important in cases in which the alleged father and/or mother of the child is deceased, where however, blood group results of other relatives are at disposal, and also in cases of suspected incest - when the alleged father of the child is at the same time father or brother of the child's mother, and, finally, in cases where two men who are related to one another are considered as possible fathers. The program can also be applied to search cases.
In 250 paternity actions (one-man one-child affairs 1965-1970) without exclusion by blood group opinion, which include 48 cases involving persons from abroad, 41 men acknowledged the paternity or withdrew the suit during the process. 32 cases were judged by default. 174 men were judged of child support according to the former 1717 BGB, 13 of these after an anthropological expertise. In 2 cases the anthropological opinion gave an indication of nonpaternity; accordingly, the court dismissed the action. In 157 cases the plausibility of paternity according to Essen-Möller's formula was calculated by the expert and dealt with in the blood group opinion. It appears, however, that the W values had no remarkable influence on the decision of the court.
Determination of genetic properdin factor B(Bf) polymorphism was carried out in immunofixation electrophoresis. Genetics of factor B were also studied after ageing, conversion with cobra venom and neuraminidase. In population studies the distribution of factor B in a West German population of 1245 non-related individuals was found to be: Bf F 2.73%, Bf FS 28.43%, Bf S 65.38%. Rare phenotypes (F 1F,F 1S, FS 1, SS 1) were seen in 3.46%. In addition a new variant, designated F1.6S, was observed. The application of factor B polymorphism to 68 paternity cases is discussed.
Using increased volumens of serum [in the Multiple-Dosage (MD) or a High Dosage (HD) test] with a sensitive manual reading technique all sera of 37 donors of blood group A2 showed irregular anti-A1(alpha1) antibodies. With the same technique, up to 1/3 of the sera of 417 healthy blood donors agglutinated red cells of a selected antigen pattern at room temperature; at 4 degrees C the ratio of positive reacting sera was much higher. The specificity of the antibodies, as indicated by the antigramme type, could be confirmed in the most cases by reacting with a series of known positive and negative reference red cells. The eluates of some of the sera yielded the same antigramme pattern as the native sera did. Some of the antibodies showed a specificity corresponding to a red cell property of the respective blood donor; but not in each case the antibodies were capable to agglutinate the donor's cells. If "autoagglutinins" were strong, frequently they revealed a character of panagglutinability, particular in the cold. With the antiglobulin test, which followed the NaCl-MD procedure, the number of positive reactions increased; on the other hand, there were some of the previously positive agglutination tests, which became negative during the course of the AHG step.
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