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K Hummel

Publications and source records attributed to K Hummel.

At least 37 records · Page 2Linked to original sources
PubMed1988

[Biostatistical evaluation of HLA-A, B findings in cases with suspected recombination].

In a given case with two or more siblings the bloodgroup findings may yield a high plausibility of paternity for the alleged father of the children whilst the HLA-A,B characteristics may exhibit an exclusion of fatherhood of one or other of the siblings. But this "exclusion" may disappear assuming an HLA-A,B recombination of a father's (or mother's) gamete. In such cases simple calculations (i.e., by hand) can provide the serostatistical characteristic L = Y/X (after Essen-Möller) for the given HLA-A,B constellation. In two-child cases with HLA-A,B findings for the putative father, the two pedigrees for the counterhypothesis Y are Yg1 and Yg2. The one holds for the case where the putative father is the father of child 1 and the other for the case where he is the father of child 2; in each case an unknown man is the father of the other child. The likelihood ratio is calculated as follows: L = Y/X = 1/r.p(3,3).p(3,4).[p(4,4) + p(4,3)]/[p(3,3).p(4,4) + p(3,4).p(4,3)], where p(3,3) and p(4,4) are the frequencies of the putative father's HLA-A,B haplotypes in the pedigree YH1, p(3,4) and p(4,3) those in pedigree YH2, and where r is the recombination rate. In three-child cases and others in which the putative father is deceased and HLA results from legitimate children or siblings are available, and in which fatherhood is only possible if a recombinant haplotype interferes, only one counter-hypothesis exists. In these cases, the likelihood ratio is represented by L = Y/X = 2/r.p(HR).2I, where p(HR) means the frequency of the recombinant HLA-A,B haplotype, r the recombination rate and I(0, 1 or 2) the "difference in determined types."

Child↗
PubMed1988

Plasminogen hemizygosity. Detection of a silent allele in 7 members of a family by determination of plasminogen phenotypes, antigenic levels, and functional activity.

The accumulation of the homozygous plasminogen (PLG) variant A3 in 4 siblings of a family led to the detection of 5 cases of apparent inverse homozygosity of PLG phenotypes which seemed to exclude paternity. Determination of 22 blood group markers and HLA typing, but under exclusion of PLG phenotypes, confirmed paternity in all cases (biostatistical probability of paternity greater than 99.9985%). Comparing the results of 'Western blots' with functional-caseinolytic phenotyping, the existence of inactive plasmin, as described earlier, could be excluded. Besides inverse homozygosity the assumption of a silent allele was confirmed by reduction of PLG antigenic levels and functional activities to approximately 50% of normal range. The PLG phenotype A in 1 individual with anamnestic thrombosis, reduced values of PLG antigen, and reduced functional activity, although in accordance with Mendelian inheritance, was also considered as indicative for PLG hemizygosity.

Alleles↗
PubMed1987

[Proof of illegitimacy and identifying the true father after 70 years].

A man born during the First World War doubted his legitimacy and believed his true father to be his mother's (since deceased) cohabitant. His and his sister's findings in less than or equal to 24 blood group systems produced a probability of sibship of W = 33%. The probability of half-sibship between the proband and two of the cohabitant's legitimate children was W = 82%, between him and two other children W = 70%, and between him and yet another two children W = 73%. These values raised doubts about the legitimacy of the cohabitant's six children. By means of serostatistics, using the blood group findings of 8 individuals it was established that it is "highly probable" that two of the six children are not the legitimate children of the cohabitant, but that their father is an unknown man. It was "practically proven", W = 99.97%, that the four legitimate children of the cohabitant are half-siblings of the proband, i.e. they all have the same father. The probability that the initial situation is correct--the proband and the cohabitant's six children are all legitimate-is "practically refuted": W = 0.03%. The probability that the position established on the basis of the blood group findings--the proband is the child of the cohabitant; two of the cohabitant's children are in fact illegitimate--is "practically proven": W = 99.97%.

Aged↗
PubMed1987

[The "utility" principle within the scope of forensic determination of blood kinship using serostatistics].

A "realistic" prior probability is always based on case experience (Akten-a-priori). In serological opinions pertaining to parentage, the realistic prior probability is only one piece of information in the whole body of evidence before the judge and does not have any special significance per se. There is no such thing as a "neutral" prior probability. It either implies "ignorance," in which case it cannot be "information," or it must be taken in connection with the utility principle, in which case it is not a "probability." The utility principle is defined in law and cannot be expressed in figures. The utility principle takes effect only when the judge reaches a decision (on the basis of all the evidence before him). It determines the relative importance of the participant's objects of legal protection which are at issue in the case. The expert is bound to apply a neutral utility component, i.e., in a two-hypothesis case (the normal situation) the significance of both the null and the counter hypothesis must carry the same weight. A null and/or a counter hypothesis can combine several single hypotheses; the mean value of their frequencies is taken. As a rule, one should avoid using a "prior case probability" ("Akten-a-priori") when calculating a W value. An "expectation of error" should be as realistic as possible and hence be obtained using a "prior case probability."

Blood Grouping and Crossmatching↗
PubMed1986

Proposal for the nomenclature of human plasminogen (PLG) polymorphism.

Since its discovery, human plasminogen (PLG) polymorphism has received widespread acceptance in population genetics and forensic haematology. Due to the large number of variant alleles described, a PLG reference typing and Plasminogen Symposium was held, at which a nomenclature proposal was inaugurated. The technology of comparing PLG variants was based on isoelectric focusing and subsequent detection by caseinolytic overlay and 'Western' blotting. Typing results permitted comparison of so far described variant designations and resulted in a new nomenclature proposal for PLG polymorphism. It is recommended that the two most common alleles found in all investigated races be called: PLG*A (previously also PLG*1) and PLG*B (previously also PLG*2), the known variants with acidic pI: PLG*A1 to *A3, intermediate variants: PLG*M1 to *M5, PLG*M5 being functionally inactive, and basic variants: PLG*B1 to *B3. For future classification of newly discovered variants, samples should be compared at any of the laboratories participating in the reference typing.

Collodion↗
PubMed1986

No fallacies in the formulation of the paternity index.

In a recent publication, Li and Chakravarti claim to have shown that the paternity index is not a likelihood ratio. They present a method of estimating the prior probability of paternity from a sample of previous court cases on the basis of exclusions and nonexclusions. They propose calculating the posterior probability on the basis of this estimated prior and the test result expressed as exclusion/nonexclusion. Their claim is wrong--the paternity index is a likelihood-ratio, that is, the ratio of the likelihood of the observation conditional on the two mutually exclusive hypotheses. Their proposed method of estimating the prior has been long known, has been applied to several samples, and is inferior (in terms of variance of the estimate) to maximum likelihood estimation based on all the phenotypic information available. Their proposed "new method" of calculating a posterior probability is based on the use of a less informative likelihood ratio 1/(1-PE) instead of Gürtler's fully informative paternity index X/Y (Acta Med Leg Soc Liege 9:83-93, 1956), but is otherwise identical to the Bayesian approach originally introduced by Essen-Möller in 1938.

Humans↗
PubMed1985

["Advantages" of exclusion probability in blood group evaluation?].

There is no apparent advantage in using exclusion probability A (or WA) in cases where parentage is disputed in either normal or special cases. Furthermore, WA provides no more information than WEM. However, the converse is true: WA does not take the serotype of the putative father into account. Moreover, it is neither easier to understand nor easier to work with and, like WEM, it also requires a prior probability. WA is also not helpful in interpreting WEM; for this, one has to use mean WEM values for fathers and non-fathers. There is no reason to expect WA and WEM to converge at the upper end of the scale. WA is unsuitable for establishing the borderline where decisions may no longer be valid, as the error quota in individual cases can be greater than that allowed within the limits. 100-WEM % is the probability or error in categorical decisions in 100 cases with similar combinations. In contrast, 100-WA % cannot provide a reliable probability of error in individual cases because WA does not take full account of the phenotype of the putative father.

Blood Grouping and Crossmatching↗
PubMed1985

The therapeutic efficacy of a xanthate compound on herpes simplex virus in skin lesions of mice and guinea-pigs.

Xanthates have recently been shown to inhibit the replication of both DNA and RNA viruses in vitro. The antiviral activity was exerted only under acidic pH conditions. Curative effects in vivo on herpes simplex virus (HSV)-induced skin lesions were only observed when the xanthate compound was administered in the form of an ointment containing acidic buffer (sodium phosphate pH 5.0). Advanced HSV-2-induced skin lesions in mice were healed by topical treatment with the xanthate compound. HSV-1-induced lesions on skin of guinea-pigs were cured within 2 days even when the treatment was initiated as late as 4 days after infection. Both HSV-1 DNA synthesis and virus production in the skin of guinea-pigs were also shown to be inhibited after treatment with the xanthate compound.

Acyclovir↗
PubMed1984

On the theory and practice of Essen-Möller's W value and Gürtler's paternity index (PI).

In cases of disputed parentage the biostatistical information is contained in the frequencies X and Y (as defined by Essen-M oller ); X denotes the hypothesis "paternity", Y the hypothesis "non-paternity". Essen-M oller proposed a probability of paternity which includes both values: W = X/(X + Y) (where X + Y becomes 1). G urtler recommends the ratio X/Y as a "Paternity Index" (= PI). Both W and PI are based on a neutral prior probability (= 0.5 in normal triplet cases) and contain the same information, though differing in form. It is this difference which can lead to different results in forensic practice. W% is the common form for expressing probabilities, and each range of W values has an appropriate, easily understood verbal predicate . By contrast, the PI value is more abstract and can be interpreted as providing fixed decision limits, a possibility increased by the lack of distinct subdivisions with verbal predicates . Tables and computer programs are available for calculating W values even in complex cases. If one chooses to use PI values instead of W they must be calculated by the following formula: (formula; see text) Calculations become complicated where more than two hypotheses are involved, as e.g. in cases involving several men ("multi-men cases"). The author cannot find any arguments for preferring PI to W. Accordingly, he recommends the use of the W value and not the Paternity Index in biostatistical evaluations of blood group findings in cases of disputed parentage.

Aged↗
PubMed1984

DNA and RNA virus species are inhibited by xanthates, a class of antiviral compounds with unique properties.

Various DNA and RNA virus species are inhibited by xanthate compounds at concentrations that leave the mitotic activity of uninfected cells unimpaired. The concentration of tricyclodecan -9-yl- xanthogenate that reduces the yield of herpes simplex virus types 1 and 2 by 50% is between 4.5 and 33 microM. The replication of DNA viruses such as simian virus 40 can be blocked at the DNA and RNA level both early and late after infection. The xanthates are not incorporated into nucleic acids. Episomal bovine papilloma virus DNA replication and transcription are also inhibited in transformed cells. The treated cells revert to the normal phenotype by acquisition of contact inhibition and a flat morphology.

Antiviral Agents↗
PubMed1983

[Evidence in cases of disputed descent from the viewpoint of the blood group expert].

The purpose of official guidelines is to ensure that when blood group serology is used to establish or contest kinship--usually a biologic child-father relationship--the prevailing conditions are both optimal and as similar as possible. Thus, they are concerned with "general conditions of evidence". Beyond this aspect there are the specific conditions of evidence pertaining to each individual case. They are based above all on the serotype of the child (and that of its mother), including, in deficiency cases, the number and relationship of relatives consulted; they affect both the exclusion expectation and the positive proof. With a new computer program it is now possible to calculate mean W values including upper and lower tail probabilities even in complex cases. From these one can determine whether or not the probability value (W) obtained in a specific case is "typical" for the alleged relationship.

Blood Group Antigens↗
PubMed1982

Calculation of percentage of cases on file with an unnamed father in 100 one-man and 100 two-man cases (filiation cases) from South-West Germany in 1976-1981. Ratio of defendants to witnesses among non-excluded men in two-man cases.

Applying the formula of Schulte-Mönting and Hummel to 100 one-man affairs (filiation cases) in South-West Germany between 1979 and 1981 gave a realistic prior probability of paternity of 0.837 +/- 0.0372. This means that in approximately 83.7% of all one-man affairs the man named by the mother to be the father of her child is indeed the father. For two-man affairs a realistic prior probability of paternity of 0.863 +/- 0.0369 was calculated on the basis of 100 two-man affairs in South-West Germany between 1976 and 1981. In other words, there is a probability of about 86.3% that a non-excludable man--irrespective of other factors--in a two-man affair is the real father of the child. In approximately 13.7% of two-man affairs neither the "defendant" nor the witness is the father, but a third unknown person. In about 85.7% of the two-man affairs in which a father of the child was named the "defendant" is in fact the father and in 14.3% the "witness" is the father.

Blood Grouping and Crossmatching↗
PubMed1982

Blood group opinions. Their importance in court.

1. --Blood group opinions based on the gene systems and characteristics usual in the FRG are able to exclude about 93% of all non-fathers. With additional systems, including the HLA system, this can be increased to between 98 and 99%. 2. --Owing to repetition, additional systems hardly improve exclusion efficiency. But each and every system is useful for positive biostatistical proof. 3. --As a rule, a computer is necessary for the biostatistical evaluation of blood group findings in cases involving aliens, deficiency, brothers, and incest. The same holds for the evaluation of HLA findings, particularly if one wants to take account of the recombination rate between locus A and B. 4. --The W-value obtained on the basis of Essen-Möller's formula contains all the information necessary for a biostatistical evaluation of triplet cases. In all other cases the method of calculation must also be based on Bayes' Theorem, if necessary with the support of Bayes' Postulate, i.e. with a neutral a priori of 0.5 as a rule [5]. Decisions limited to probably values serve little purpose in court cases.

Blood Group Antigens↗
PubMed1980

[Red cell and serum polymorphisms to define main human races and to analyze mixed populations (author's transl)].

Using blood group serological chromosome markers one can distinguish by means of an integrating mathematical method of comparison at least five by and large pure, basic human races. These are: the Amerindios, the Caucasians, the Melanesians, The Negroids, and the Poly-Micronesians. A sixth race, the Neomongoloids, can be constructed on the basis of blood group characteristics from the mixed populations of the Far East. The Chinese, Japanese, and Ainu ethnic groups have large portions of this blood. It appears that the purest representatives of this sixth race are the Koreans. An analysis of blood group genes revealed signs of genetic drift among the Ainus, the Australian Aborigines, the Central and South American Indians (and, indirectly, also among the North American Indians) as well as among the Xhosas and Bantu. The gene impoverishment resulting from this drift may be a contributory factor to the problems of existence which these peoples have been experiencing in recent times.

Blood Group Antigens↗
PubMed1978

[Highly different values for the plausibility of fatherhood and for the exclusion chance (author's transl)].

More than 1800 HLA-typed mother-child-putative father triplets were biostatistically analyzed on the basis of the Essen-Möller principle. 14 of them had W-values (= probability of paternity) of less than 50%, the lowest value being 4,4%. Using a specially designed computer program, exclusion probabilities between 68 and 96% were calculated. This demonstrates (a) that nonexclusion is not necessarily in every case a positive indication of the paternity of the man involved; and (b) that the probability of exclusion as a biological method of establishing paternity is not a suitable piece of evidence. The W-value (= "probability of paternity"), obtained on the basis of the Essen-Möller principle, provides complete information, and is alone conclusive.--The high proportion of non-fullhouse children among the 14 cases allows the conclusion that the more comprehensive the specificity spectrum of the antiserums used in the typing is, the fewer the number of such cases.

Blood Group Antigens↗