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Background The ABO blood group is important in blood transfusion. Recently, an erythroid cell-specific regulatory element has been identified in the first intron of ABO using luciferase reporter assays with K562 cells. The erythroid cell-specific regulatory activity of the element was dependent upon GATA-1 binding. In addition, partial deletion of Intron 1 including the element was observed in genomic DNAs obtained from 111 Bm and ABm individuals, except for one, whereas the deletion was never found among 1005 individuals with the common phenotypes. Study Design and Methods In this study, further investigation was performed to reveal the underlying mechanism responsible for reduction of B antigen expression in the exceptional Bm individual. Peptide nucleic acid-clamping polymerase chain reaction was carried out to amplify the B-related allele, followed by sequence determination. Electrophoretic mobility assays and promoter assays were performed to examine whether a nucleotide substitution reduced the binding of a transcription factor and induced loss of function of the element. Results Sequence determination revealed one point mutation of the GATA motif in the element. The electrophoretic mobility shift assays showed that the mutation abolished the binding of GATA transcription factors, and the promoter assays demonstrated complete loss of enhancer activity of the element. Conclusion These observations suggest that the mutation in the GATA motif of the erythroid-specific regulatory element may diminish the binding of GATA transcription factors and down regulate transcriptional activity of the element on the B allele, leading to reduction of B antigen expression in erythroid lineage cells of the Bm individual. [ABSTRACT FROM AUTHOR]

BACKGROUND: Our previous studies of the transcriptional regulation of the human ABO gene indicated that negative regulatory elements are present in the sequence just upstream from the proximal promoter. The role of the -275 to -118 region in regulation of ABO gene transcription is further characterized. STUDY DESIGN AND METHODS: Transient transfection experiments into various cells were performed with luciferase reporter plasmids carrying ABO upstream sequences, and electrophoretic mobility shift assay was carried out with a nuclear extract prepared from the human gastric cancer KATOIII cells. RESULTS: It is shown that the -202 to -118 region is involved in the negative regulation of ABO gene transcription in all cell lines examined. Transient transfection experiments in KATOIII cells with a reporter plasmid carrying mutated N box at -196 to -191 demonstrate that the N box is a negative regulatory element in the -202 to -118 sequence. Electrophoretic mobility shift assays indicate that the N box binds with a nuclear factor from KATOIII cells. CONCLUSION: These results indicate that repression of transcription from the ABO proximal promoter is partially dependent upon the N box. Therefore, reduced binding of the protein with the N box might play a direct role in ABO gene expression. [ABSTRACT FROM AUTHOR]

Forensic pathologists often encounter cases of acute subdural hematoma (SDH) due to trauma, whereas those attributable to endogenous causes are rare. Here, we report a case of the latter type in a 42-year-old man who was found dead at home after several months of fever and malaise. Postmortem computed tomography (PMCT) and autopsy were undertaken to clarify the cause of death. PMCT images revealed a fatal SDH and a localized hyper-density area in the right parietal lobe; macroscopic and microscopic examinations revealed SDH due to rupture of a mycotic aneurysm (MA) associated with meningitis. The PMCT images also indicated thickening and calcification of the mitral valve, while autopsy demonstrated infective endocarditis (IE). In addition, PMCT demonstrated a low-density area in the spleen, which was shown to be a splenic abscess at autopsy. PMCT also demonstrated tooth cavities. Based on the findings of autopsy, the cause of death was considered to be SDH due to rupture of the MA resulting from meningitis with IE and splenic abscess. Although PMCT was unable to clarify the significance of any individual feature, a retrospective review of the PMCT images might have suggested IE, bacteremia, or ruptured MA leading to SDH. This case suggests that, instead of interpreting individual features demonstrated on PMCT images, integrated interpretation of overall PMCT findings might provide clues for identifying causes of death, despite the fact that PMCT lacks diagnostic accuracy for infectious diseases such as IE and meningitis. [ABSTRACT FROM AUTHOR]

Sudden death, or unexpected natural death of a healthy individual, is a serious problem in all nations. Sudden cardiac death (SCD) mainly due to ischemic heart diseases is the top cause of sudden death. However, there are pathophysiological conditions, referred to as sudden arrhythmic death syndrome, in which no apparent lesion can be identified even after complete conventional or ordinary autopsy. While postmortem genetic analyses have accumulated evidence about underlying genetic abnormality in such cases, the precise relationships between genetic background and the phenotype have been largely elusive. In this study, a retrospective investigation of 17 autopsy cases in which lethal arrhythmia was suspected to be the cause of death was carried out. Genetic analysis focusing on 72 genes reported to be associated with cardiac dysfunctions was performed, in combination with detailed histopathological and postmortem imaging examination, and a family study. As a result, in two cases of suspected arrhythmogenic cardiomyopathy (ACM), we found a nonsense variant in PKP2 and frameshift variant in TRPM4 gene. In contrast, the other 15 cases showed no morphological changes in the heart despite the presence of a frameshift variant and several missense variants, leaving the clinical significance of these variants obscure. The findings of the present study suggest that nonsense and frameshift variants could be involved in the morphological abnormality in cases of SCD due to ACM, while missense variants alone rarely contribute to massive structural changes in the heart. [ABSTRACT FROM AUTHOR]

A- and B-antigens are present on red blood cells (RBCs) as well as other cells and secretions in Hominoidea including humans and apes such as chimpanzees and gibbons, whereas expression of these antigens on RBCs is subtle in monkeys such as Japanese macaques. Previous studies have indicated that H-antigen expression has not completely developed on RBCs in monkeys. Such antigen expression requires the presence of H-antigen and A- or B-transferase expression in cells of erythroid lineage, although whether or not ABO gene regulation is associated with the difference of A- or B-antigen expression between Hominoidea and monkeys has not been examined. Since it has been suggested that ABO expression on human erythrocytes is dependent upon an erythroid cell-specific regulatory region or the + 5.8-kb site in intron 1, we compared the sequences of ABO intron 1 among non-human primates, and demonstrated the presence of sites orthologous to the + 5.8-kb site in chimpanzees and gibbons, and their absence in Japanese macaques. In addition, luciferase assays revealed that the former orthologues enhanced promoter activity, whereas the corresponding site in the latter did not. These results suggested that the A- or B-antigens on RBCs might be ascribed to emergence of the + 5.8-kb site or the corresponding regions in ABO through genetic evolution. [ABSTRACT FROM AUTHOR]

• A diagnosis with CA19-9 is not appropriate for cancer patients who lack the Le gene in the Lewis blood group system. • A novel genotyping method for rapid identification of the Le gene in diluted blood samples was developed. • Presence or absence of the Le gene could be simply determined with a good performance feature. The antigenic determinant of CA19-9 is synthesized by the α1,3/4fucosyltransferase encoded by the Le gene in the Lewis blood group system. Accordingly, a diagnosis with CA19-9 is not appropriate for Le -negative patients who possess the Le gene-mutated le alleles homozygously. A Le gene-specific PCR was undertaken to determine c59T>G by using a set of tag-sense and biotin-labeled anti-sense primers and a peptide nucleic acid- le- clamp which bound to G59 in the le alleles. Following mixing with streptavidin-coated blue latex beads, the PCR products were developed on a strip on which the complementary tag oligonucleotide to the Le gene-specific amplicon was immobilized. When the PCR products were developed on the strip, a clear line was rapidly observed in Le -positive but not in Le -negative individuals. In contrast, a significant number of cancer patients with Lewis-negative phenotype were found to possess CA19-9, while they were specifically genotyped as Le /-. No contradictory results were observed in cancer patients (n = 315) with respect to their Lewis genotypes and CA19-9 levels. c59T>G occurred commonly in the le alleles could be specifically and rapidly identified by the present method. This method appeared to be relevant for selecting cancer patients to be diagnosed with CA19-9. [ABSTRACT FROM AUTHOR]