Biomedical subjects

Hiroshi Ideguchi

Publications and source records attributed to Hiroshi Ideguchi.

6 recordsLinked to original sources

PubMed2006

Porphyromonas gingivalis-induced platelet aggregation in plasma depends on Hgp44 adhesin but not Rgp proteinase.

Evidence from recent epidemiological studies suggests a link between periodontal infections and increased risk of atherosclerosis and related cardiovascular and cerebrovascular events in human subjects. One of the major pathogens of periodontitis, Porphyromonas gingivalis, has the ability to aggregate human platelets in platelet-rich plasma (PRP). Mechanism of P. gingivalis-induced platelet aggregation in PRP was investigated. Proteinase inhibitors toward Arg-gingipain (Rgp) and Lys-gingipain (Kgp) did not suppress P. gingivalis-induced platelet aggregation in PRP, whereas the Rgp inhibitor markedly inhibited P. gingivalis-induced platelet aggregation using washed platelets. Mutant analysis revealed that P. gingivalis-induced platelet aggregation in PRP depended on Rgp-, Kgp- and haemagglutinin A (HagA)-encoding genes that intragenically coded for adhesins such as Hgp44. Hgp44 adhesin on the bacterial cell surface, which was processed by Rgp and Kgp proteinases, was essential for P. gingivalis-induced platelet aggregation in PRP. P. gingivalis cell-reactive IgG in plasma, and FcgammaRIIa receptor and to a lesser extent GPIbalpha receptor on platelets were found to be a prerequisite for P. gingivalis-induced platelet aggregation in PRP. These results reveal a novel mechanism of platelet aggregation by P. gingivalis.

Adhesins, Bacterial↗

PubMed2006

[Diagnosis and gene analysis of congenital hemolytic anemia].

Congenital hemolytic anemia is relatively uncommon and tends to be left undiagnosed because unusual special tests outside health insurance adaptation are needed for the diagnosis. To diagnose properly these patients, we instituted a comprehensive examination system for hemolytic anemia in Fukuoka University Hospital in 1990. In addition to basic laboratory tests, investigation of hemoglobin, SDS-PAGE analysis of red blood cell membrane proteins, a complete panel of red cell enzyme measurements and gene analysis were included. The red cell enzyme measurements was facilitated by the automation on the COBAS MIRA instrument (NIPPON ROCHE). By such a comprehensive examination, we have identified and confirmed 382 cases of congenital hemolytic anemia which otherwise would have escaped detection during the period October 1990 to September 2005 in our institution. SDS-PAGE procedure contributed to the diagnosis of 24 cases of band 3 deficiency, 13 cases of band 4.2 deficiency and 13 cases of band 4.1 deficiency. Hemoglobin studies uncovered 20 cases of abnormal hemoglobins, 126 cases of beta thalassemia and 7 cases of alpha thalassemia. Red cell enzyme measurements were also contributory to the diagnosis of 29 cases of hemolytic anemia in which enzyme levels were reduced.

Anemia, Hemolytic, Congenital↗

PubMed2005

[Congenital hemolytic anemia].

Gene analysis in Japanese patients with congenital hemolytic anemia due to red cell membrane disorders, thalassemias, unstable hemoglobinopathies and red cell enzymopathies were summarized. In hereditary spherocytosis, twenty-four mutations of band 3, five mutations of protein 4.2 and twenty mutations of ankyrin have been identified. In beta thalassemia, fourty-seven mutations of beta globin have been found, and ten mutations among them comprise 80% of beta thalassemia patients in Japan. Most common alpha0 and alpha+ thalassemia are--SEA and--alpha3.7, respectively. Fourty glucose-6-phosphate dehydrogenase mutations and twenty-three pyruvate kinase mutations have been identified, allowing a better understanding of the structure-function relationships of these enzymes.

Anemia, Hemolytic, Congenital↗

PubMed2004

Characterization of a highly polymorphic marker adjacent to the SLC4A1 gene and of kidney immunostaining in a family with distal renal tubular acidosis.

BACKGROUND: Mutations in the human SLC4A1 (AE1/band 3) gene are associated with hereditary spherocytic anaemia and with distal renal tubular acidosis (dRTA). The molecular diagnosis of AE1 mutations has been complicated by the absence of highly polymorphic genetic markers, and the pathogenic mechanisms of some dRTA-associated AE1 mutations remain unclear. Here, we characterized a polymorphic dinucleotide repeat close to the human AE1 gene and performed an immunocytochemical study of kidney tissue from a patient with inherited dRTA with a defined AE1 mutation. METHODS: One CA repeat region was identified in a phage P1-derived artificial chromosome (PAC) clone containing most of the human AE1 gene and the upstream flanking region. We determined its heterozygosity value in multiple populations by PCR analysis. Genotyping of one family with dominant dRTA identified the AE1 R589H mutation, and family member genotypes were compared with the CA repeat length. AE1 and vH(+)-ATPase polypeptides in kidney tissue from an AE1 R589H patient were examined by immunocytochemistry for the first time. RESULTS: This CA repeat, previously reported as D17S1183, is approximately 90 kb upstream of the AE1 gene and displayed considerable length polymorphism, with small racial differences, and a heterozygosity value of 0.56. The allele-specific length of this repeat confirmed co-segregation of the AE1 R589H mutation with the disease phenotype in a family with dominant dRTA. Immunostaining of the kidney cortex from one affected member with superimposed chronic pyelonephritis revealed vH(+)-ATPase-positive intercalated cells in which AE1 was undetectable, and proximal tubular epithelial cells with apparently enhanced apical vH(+)-ATPase staining. CONCLUSIONS: The highly polymorphic dinucleotide repeat adjacent to the human AE1 gene may be useful for future studies of disease association and haplotype analysis. Intercalated cells persist in the end-stage kidney of a patient with familial autosomal dominant dRTA associated with the AE1 R589H mutation. The absence of detectable AE1 polypeptide in those intercalated cells supports the genetic prediction that the AE1 R589H mutation indeed causes dominant dRTA.

Acidosis, Renal Tubular↗

PubMed2003

Dominant beta-thalassemia with hemoglobin Hradec Kralove: enhanced hemolysis in the spleen.

We describe a 6-year-old girl and her mother with dominant beta-thalassemia due to hemoglobin Hradec Kralove (Hb HK). Both patients presented microcytic anemia, jaundice, splenomegaly, cholelithiasis, and recurrent hemolytic bouts. Osmotic resistance tests using saline and coiled planet centrifugation revealed the increased fragility of the red cell membrane. On the other hand, the glycerol lysing time was prolonged, and results of the isopropanol test were weakly positive. Despite mimicking the features of hereditary spherocytosis, the results of the genetic analyses verified the second reported family with Hb HK (codon 115, GCC [Ala] --> GAC [Asp]). Splenectomy was effective for the amelioration of hemolysis. Of 7 reported patients with Hb variants at beta-globin codon 115 (Hb Madrid and Hb HK), 5 underwent splenectomy. Because of the variable augmentation of extramedullary hemolysis in dominant beta-thalassemias, genotyping is necessary for determining the clinical indication of splenectomy.

Adult↗

PubMed2002

Enhanced haemolysis with beta-thalassaemia trait due to the unstable beta chain variant, Hb Gunma, accompanied by hereditary elliptocytosis due to protein 4.1 deficiency in a Japanese family.

We identified a Japanese family with a beta-thalassaemia trait and hereditary elliptocytosis (HE). We studied five members of this family. One was normal, one had only the beta-thalassaemia trait, one had heterozygous HE, and two had compound heterozygous beta-thalassaemia trait and HE. The last two had already undergone splenectomy. The molecular profile of beta-thalassaemia was consistent with that of Hb Gunma: codon 127/128CAGGCT(Gln-Ala)--> CCT(Pro). Analysis of erythrocyte membrane proteins revealed a partial deficiency of protein 4.1 in all those with HE, whereas the spectrin content was within the normal range. Each heterozygous family member with either the beta-thalassaemia trait or HE was asymptomatic, whereas the two with both beta-thalassaemia and HE had marked red blood cell deformities and haemolysis. The abnormalities of the red blood cells in patients with the beta-thalassaemia trait might be enhanced by association with HE owing to a protein 4.1 deficiency.

Adult↗