Biomedical subjects
Publications and source records attributed to D Chandanayingyong.
Two examples of anti-Hut which is specific for cell class II of the Miltenberger complex were found by simple absorption test of previously called 'anti-Mi-a'.
Explore the source record for details and available documents.
We have sequenced exons 2, 3 and 4 of MIC-A in 23 homozygous cell lines, 22 families and 54 unrelated individuals. This has led to the definition of seven polymorphic positions in exon 2, 13 in exon 3 and 12 in exon 4, yielding a total of 33 different MIC-A allelic specificities, of which 16 have not been described before. The newly defined sequences and those of the alleles defined before were entered into a database of the SCORE program (Helmberg et al., 1998, Tissue Antigens, 51, 587) for comprehensive genotyping analysis. In the tested sample, only one genotype present in two individuals gave rise to an ambiguous genotype. If all possible combinations of the 33 alleles are considered, 10 of 636 combinations are ambiguous. The MIC-A exon 2, 3 and 4 polymorphism is characterized by diallelic single base exchanges and by a considerable degree of exon shuffling. The majority of heterozygote positions identified are non-synonymous, i.e. five of seven in exon 2, 13 of 13 in exon 3 and eight of 12 in exon 4, suggesting an important function for the MIC-A polymorphism.
Anti-EnaFS was detected in the serum of a Caucasian woman, K.T., during her third pregnancy. She had not been transfused. At delivery, the infant's red cells (RBCs) had a negative direct antiglobulin test. The antibody was inhibited by isolated MN sialoglycoprotein (SGP). Unlike other En(a-) cells, K.T.'s EnaFS-negative RBCs were found to demonstrate normal sialic acid levels, and an MN SGP exhibiting normal sodium dodecylsulphate electrophoretic mobility and periodic acid-Schiff staining intensity. K.T., whose parents were consanguineous, appears to be the first known MiVII homozygote. In a three-generation family study, MiVII was shown to travel with MS. The Anek receptor of K.T.'s RBCs was found to be located on the trypsin-resistant and V8 protease-sensitive portion of the MN SGP (residues 40 to 57), whereas the Anek receptor of MiVI RBCs was shown to be associated with their abnormal Ss SGP. K.T.'s MN SGP appears to exhibit an amino acid sequence alteration in the region of the EnaFS determinant, which is located within the residues 46 to 56 of the normal MN SGP. These findings suggest that the MiVII and EnaFS receptors are the products of allelic genes.
Explore the source record for details and available documents.
We have determined by sequencing the allelic variation in intron 2 and 3 of hte MICA gene for a total of 22 different alleles. Sequencing of introns was performed in two directions, using DNA from homozygous cell lines from families and from unrelated individuals. Intron 2 is 273 bp long and did in the alleles investigated not reveal any length polymorphism. We found a total of eight polymorphic positions which exhibit a strict biallelism, as it is also found in the polymorphisms for exon 2, 3 and 4 of MICA. Intron 3 is 586 bp long an required an additional set of primers placed near the middle of this intron in order to allow a complete bidirectional sequence. In intron 3, a total of 10 polymorphic positions were identified. Interestingly, we found two variants of the allele MICA*002 which are distinguished only by one basepair difference in intron 3. The variant MICA*002A is associated with HLA-B35 and B58, while the allele MICA*002B is associated with B38 and B39.