Biomedical subjects
Publications and source records attributed to P Prodanov.
The results of serological studies of Zea mays everta seed extracts with anti-B specificity are presented. Lectin will agglutinates A1B erythrocytes significantly more weakly than erythrocytes of B and A2B blood groups.
Results of the screening of aberrant (paradoxal) secretors in 14372 healthy donors and 614 patients with ulcus duodeni are presented. An extremely high frequency of aberrant secretors was established (12.6%) in patients with ulcus duodeni in comparison to donors (0.10%). A new type of aberrant secretors was registered in patients of A1 and A1B blood groups. Their salivas normally inhibited anti-A sera, but the expected inhibition of anti-A1 reagents (dolichos biflorus) could not be observed. The data of comparative quantitative investigations of the inhibiting strength of the ABH antigen in salivas of normal secretors, nonsecretors and aberrant secretors are presented. Various theoretical explanations of aberrant secretors are discussed.
By means of quantitative agglutination, the results of interactions of A subgroup and variant genes with the B gene, as well as interactions of the Bx allele with A1, A2 and O genes in their heterozygous combination, are demonstrated. In the majority of interactions, competition occurs according to the rule that the allele producing the more active enzyme reduces the original activity of the enzyme produced by the relatively weaker allele. That the opposite result of interaction can occur also is shown in examples of Bx variants, when in A1Bx and A2Bx combinations complementation and a partial or nearly total normalization of the phenotypic expression of B antigen on red cells and in saliva happen. The phenomenon of competition, but even more so, the phenomenon of complementation, may have a broader importance than only for the ABO blood group system.
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The results of serological investigations of a new anti-H lectin obtained from the leaves of Sambucus nigra are presented. In saline extracts the lectin is useful for investigating the ABO secretors' status, A-subgroups and absorption-elution experiments as well.
The results of serological investigations of human type ABH antigens and antibodies of 116 sheep are presented. Traces of ABH antigens on sheep erythrocytes are recognized by elution. Agglutinins with anti-AA1, anti-B and sometimes anti-H specificity besides of heteroagglutinins were differentiated by cross-absorption experiments. It was established that the sheep saliva also contains H antigens and sometimes A and/or A1 antigens. On the basis of their serological characteristics the sheep divided into 11 serological groups. In order to explain some serological peculiarities in sheep the existence of genes for regulation, the production of ABH antigens in glucolipid form and genes for regulation of the same antigens in glucoprotein form were postulated.
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The results of comparative quantitative investigations of the inhibiting strength of salivas from adults and newborn infants are presented. It is found that A and B salivary antigens of newborn infants have a significantly weaker inhibiting strength than those of adults. Opposite proportions are established in relation to salivary H antigens. Two types of quantitative changes of the inhibiting strength of the salivas from AB groups are registered and they are supposed to be a result of the competition of A and B gene products.
In a systematic study of more than 100.000 subjects, the authors have put forward eight AHm, one AHmB and three OHm. The determination of these phenotypes is based solely on immunogenetic background (quantitative study of A,B,H, antigens, study of anti-H anti-A and anti-B allo hemagglutinins, study of salivary substances). To explain these variants, the authors suggest that suppressor non allelic genes are controlling the phenotypes of H antigens.
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The result of a screening of ABO (Hh) variants after investigating the blood group of 106,980 persons are presented. The Ax variant is registered most frequently among the Bulgarian population. As a whole the frequencies of ABO blood group variants Ax, Ael, A3, Aend and Am among the Bulgarian population are similar to that established by other authors among the French population and nearly twice as high as among the population of Bombay. The group of H-deficient phenotypes includes AA1Xh, AHm, OHm variants. Their frequency is significantly lower when compared with the frequency of AHm and OHm variants among the population of Thailand. Variants A1 and Aint with unusually high H-content are classified as A1H, A1Hint, Aint H and integrated as a category of H-excess phenotypes. Their incidence among the Bulgarian population is significantly lower than that registered among Maharastrian, South African Bantu and Indian.
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During the investigation of the subgroups of 45,895 A blood group persons, H-excess A1 and Aint variants were found in 0.359%. These variants were subdivided into three categories provisionally named A1H, A1Hint and AintH according to their most typical isoserological characteristics. The results of genealogical investigation are presented. An attempt was made to explain the existence of these atypical subgroups.
The results of a comparative quantitative investigation about the agglutinability of erythrocyte antigens A, B, and H to be found in fetus (fifth to ninth lunar month), newborns, adults, and old age people are represented. In investigating with anti-H sera it could be found that A-antigens in fetus undergo the same development to be observed in newborns; it amounts to 75% of the agglutinability present in adults. After delivery the agglubinability will essentially increase up to the fifth month; it will only reach the average values of adults, however, after the seventh year of age and will remain unchanged then until the end of life. The agglutinability of B-erythrocytes with anti-B will also change in the same way. In fetus and newborns the agglutinability of A1 erythrocytes with anti-A1 sera is markedly weaker than that determined by anti-A sera. After delivery it will rapidly increase, will be stronger afterwards than the agglutinability with anti-A sera and will have the values to be found in adults after the third year of age. After the 85 year of age, however, there is a tendency of weakening the agglutinability with anti-A1 serum. With growing age the agglutinability of O-erythrocytes with anti-H serum is changed in the same way. Furthermore, it could be detected that the interaction between genes A1 and B to be found in adults will find its expression in a weakening of the agglutinability of A1B-erythrocytes with anti-A1 and anti-B sera, the agglutinability with anti-A serum remaining constant. This behaviour is valid for the whole life of man. In all stages of life an interaction between weak and strong genes can be observed in A2B-erythrocytes.
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