PubMed Health⌕ Search

Biomedical subjects

K Harano

Publications and source records attributed to K Harano.

At least 37 records · Page 2Linked to original sources

Japanese beta zero-thalassemia: molecular characterization of a novel insertion causing a stop codon.

During a physical checkup, a 42-year-old Japanese man with liver dysfunction was diagnosed as having beta-thalassemia. Using molecular biological techniques including PCR, we investigated the chemical basis of the hematological disorder. We found that a frameshift attributable to the insertion of a thymidine into or following the TTT sequence of codon 42 transformed codon 43 (GAG) into a stop codon (TGA). We believe that this mutation has not been previously reported.

Adult↗

The COL4A5 gene in Japanese Alport syndrome patients: spectrum of mutations of all exons. The Japanese Alport Network.

To determine the spectrum of mutations of the COL4A5 gene encoding type IV collagen among Japanese Alport syndrome (AS) patients, 60 unrelated patients (47 males and 13 females) from all over the country were recruited. Screening for mutations in all the exons (1 to 51) of the COL4A5 gene was carried out by PCR-SSCP analysis. A mobility shift was observed in 22 of 60 patients, and their genomic DNA were analyzed by the direct sequence method and using cloned ssDNA. Nine of these had missense mutations in the collagenous domain (in exons 39, 37, 31, 29, 28, 27, 21, 20, 19). Eight of these mutations were observed in a codon of glycine residue. Two were altered to arginine, two to valine, two to glutamic acid and two to aspartic acid. The other missense mutation was a change from isoleucine to serine in a interruption region. Five patients had small size base deletions and one had a 4 bp insertion resulting in frameshift (in exons 49, 41, 19, 14, 13). Three had a splice site mutation (in exons 49, 47, 27). One had a nonsense mutation (in exon 17). These mutations seemed to be pathogenic, but the phenotype, which includes extrarenal manifestations, can vary with respect to both expression and severity. The remaining mutations were three silent ones (in exons 19, 39, 46). In addition, major gene rearrangement seemed to be rare in Japanese AS patients.

Adult↗

A single-base mutation in exon 31 converting glycine 852 to arginine in the collagenous domain in an Alport syndrome patient.

In a family with Alport syndrome, molecular analysis of the COL4A5 gene, which encodes the alpha 5(IV) chain of glomerular basement membrane collagen, revealed a GGA-->AGA change in exon 31, resulting in substitution of an arginine for a glycine in position 852 of the polypeptide chain, between interruptions 16 and 17 of the triple-helical collagenous domain. The mutation causes the MaeI restriction sites, and could be easily diagnosed in the family members through restriction analysis. This one point mutation can be expected to interrupt type IV collagen molecules.

Adult↗

Hb Toranomon [beta 112(G14)Cys-->Trp]: a new unstable electrophoretically silent hemoglobin.

We describe a silent and unstable hemoglobin variant, Hb Toranomon, which was discovered by high performance liquid chromatography in an apparently healthy Japanese male during a Hb A1c assay. Isoelectrofocusing of his hemolysate and chromatographic separation of globin on a CM-cellulose column revealed no abnormality. The isopropanol precipitation test gave a positive result. Amino acid analysis of all peptides isolated from the tryptic digests of the aminoethylated and non-aminoethylated beta chain (beta A + beta X) by reversed phase high performance liquid chromatography indicated a substitution of Cys-->Trp at position 112 of the beta chain, which was confirmed by protein sequencing. cDNA sequencing showed the nucleotide sequence of the beta 112 codon to be TGG instead of TGT, confirming the amino acid substitution described above. The globin biosynthesis ratio (beta/alpha) was 1.00.

Adult↗

[The higher structure and physiological significance of hemoglobin].

The major function of hemoglobin, which is known as a highly advanced allosteric protein, is the transportation of oxygen and carbon dioxide between the lung and the tissues. Hemoglobin not only has the capability of binding a large quantity of oxygen but also the property of releasing oxygen in tissues where the pressure of oxygen is reduced with increase in the pressure of carbon dioxide. Thus, the blood can efficiently carry oxygen from the lung to the tissues. This physiological phenomenon is related strongly to the interaction between the higher structure of hemoglobin and various kinds of ions, e.g., H+, HCO3-, and 2,3-diphosphoglycerate.

Hemoglobins↗

An antiserum to a synthetic fimbrial peptide of Actinobacillus actinomycetemcomitans blocked adhesion of the microorganism.

The purpose of this study is to certify the importance of the fimbriae as an attachment factor of Actinobacillus actinomycetemcomitans, a human periodontopathic bacterium, and the significance of anti-fimbrial antibody function as an attachment inhibitor. Fimbrial antigen was prepared from the A. actinomycetemcomitans 310-a strain. Oligopeptides were synthesized according to the amino acid sequence of the fimbrial protein. The peptide antigen was conjugated with branched lysine polymer resin beads. The peptide antigen was suspended in PBS emulsified with incomplete Freund's adjuvant and used to immunize rabbits. A rabbit antiserum reacted with an approximately 54 kDa protein of the fimbriae protein from A. actinomycetemcomitans 310-a and with those of other fimbriated strains. This antiserum strongly inhibited the attachment of fimbriated A. actinomycetemcomitans strains to saliva-coated hydroxyapatite beads, buccal epithelial cells, and a fibroblast cell line, Gin-1. Such a synthetic fimbrial peptide antigen may be effective in inducing antibodies which inhibit adhesion and subsequent colonization by A. actinomycetemcomitans.

Aggregatibacter actinomycetemcomitans↗

Band 4.2 Komatsu: 523 GAT-->TAT (175 Asp-->Tyr) in exon 4 of the band 4.2 gene associated with total deficiency of band 4.2, hemolytic anemia with ovalostomatocytosis and marked disruption of the cytoskeletal network.

A novel mutation of 523 GAT-->TAT (175 Asp-->Tyr) in exon 4 of the band 4.2 gene was detected in a 37-year-old Japanese patient with total lack of band 4.2 protein, designated as allele 4.2 Komatsu. In this patient, moderate uncompensated hemolytic anemia (red cell count 3.38 x 10(6)/microliters, hemoglobin 10.8 g/dl, hematocrit 30.9%, reticulocytes 12.4%, indirect bilirubin 1.84 mg/dl) with ovalostomatocytosis and increased osmotic fragility had been noted since birth. Family studies revealed no overt hemolytic anemia in other family members, essentially normal red cell morphology, and a normal profile of red cell membrane proteins including band 4.2. Genetic studies proved that the proband was homozygous and all the family members studied were heterozygous with respect to the mutation of 523 GAT-->TAT of the band 4.2 gene. Although band 4.2 was completely absent in the proband, trace amounts of 72 kDa and 74 kDa peptides were detected in the red cells of all the family members, in which the mutation of 424 GCT-->ACT at exon 3 of the band 4.2 gene (Nippon type) was not present. Electron microscopic studies with the surface replica method and the quick-freeze deep-etching method showed the most marked disorganization of the cytoskeletal network in the patient's red cells in situ among the cases of band 4.2 deficiencies we have studied. This suggests that the amino acid of the band 4.2 protein, which was affected by the present mutation in exon 4, is much more crucial for the functioning of band 4.2 protein than that at codon 142 in exon 3. The cytoplasmic domain of band 3 in the proband's red cells was essentially normal in protein chemistry and in gene analysis with single-stranded conformation polymorphism (SSCP).

Adult↗

Thalassemia incidentally found by marked erythrocytosis due to an ochre mutation at codon 35 in a Japanese man.

We present a patient with beta-thalassemia minor diagnosed on the basis of the incidental findings of marked hypochromic and microcytic erythrocytosis. Hemoglobin analysis revealed increased hemoglobin (Hb) A2 levels and decreased beta/alpha synthesis ratio in both the propositus and his mother. Further molecular studies identified a single base substitution of TCA to TAA within codon 35 in heterozygous state, which creates a premature terminator resulting in a defect of effective beta globin synthesis. This is the first report of beta-thalassemia due to a nonsense mutation at codon 35 of beta-thalassemia gene in the Japanese population.

Adult↗

[An abnormal hemoglobin which was found by chance at a health checkup].

A 68-year-old female visited our hospital because of low hemoglobin A1c content, which was found by chance at a health checkup. She did not have any symptom or sign except hypertension and low HbA1c. To determine the reason why HbA1c was so low in usual laboratory test, we carried out isoelectrofocusing (IEF) of the hemolysate, Hb instability test, and detection and isolation of the abnormal globin chain by urea CM-cellulose column chromatography. The abnormal beta-globin chain was digested with TPCK-trypsin, and the tryptic peptides were separated by HPLC on a reversed phase column. Finally the determination of amino acid composition and amino acid sequence of the abnormal peptide were performed. The Hb variant was identified as Hb Riyadh (beta 120Lys-->Asn). The detection and analysis of abnormal hemoglobin will be expected to increase in accordance with the increased opportunity of public health checkup.

Aged↗

Three-dimensional analysis of the intrinsic cardiac ganglia in a young dog.

The intrinsic ganglia of the heart of a young dog were studied by computer graphic reconstruction to determine the accurate location. The heart was embedded in celloidin, and transverse sections were cut. Using every third 60 microns section, a series of 49 sections was mapped. Three-dimensional (3D) images were constructed by a personal computer. Numerous intrinsic ganglia, most of which were located in the epicardiun, were observed. The intrinsic ganglia were found in the base of the aorta and pulmonary vessels and from the base of the superior vena cava to the right atrium, i.e., the sinoatrial nodal region. Using the 3D reconstruction technique, the locations of the intrinsic ganglia could be accurately identified. Furthermore, it was demonstrated that these ganglia formed several groups which formed a continuity. This study suggested that it was necessary to consider the existence of the numerous intrinsic ganglia, when we studied the cardiac innervation.

Animals↗

[Hb M-Iwate [alpha 87 (F8) His-->Tyr]: analysis of the genomic DNA and biosynthesis].

Hb M-Iwate [alpha 87 (F8) His-->Tyr] was identified as the cause of cyanosis in a 21-year-old Japanese female. Amplification and sequencing of the alpha 2- and alpha 1-genes demonstrated the mutation CD87 CAC (His)-->TAC (Tyr) in the alpha 2-gene. Analysis of the in vitro globin biosynthesis in the reticulocytes disclosed a well-balanced beta/alpha synthetic ratio of 1.04 but an unexpectedly low alpha M/total alpha. Although the cause of the lowered alpha M-globin biosynthesis is not yet clear, it might be related to a defect in chain assembly rather than to a modified stability or a reduced amount of the abnormal alpha-globin mRNA.

Adult↗

Epidural block for treatment of intestinal obstruction--clinical and experimental studies.

Seventy patients with intestinal obstruction were managed with usual conservative treatments and epidural anesthesia to block splanchnic and somatic nervous systems, for nine years from 1981 to 1990. Improvement of clinical symptoms and general conditions was accomplished in 48 patients (68.6%). In these 48 patients, 41 patients (58.6%) had complete remission of intestinal obstruction, showing flatus in 8.3 hours on an average, but seven (10.0%) had incomplete remission. For these seven, after improvements of their clinical symptoms, elective radical operations were performed within three weeks. In 22 (31.4%) patients whose symptoms were not improved at all with the epidural block, emergency exploratory celiotomies were performed, 15.4 hours on an average after the initial epidural block. Indications for surgical intervention of intestinal obstruction were decided by the absent movement of gas in the bowel in a series of plain X-rays. The effectiveness of the epidural block on the motility of the obstructed intestinal loop was experimentally confirmed in monkeys. We suggested that the epidural block, accompanied with usual conservative treatments, be recommended as the initial treatment for intestinal obstruction.

Journal Article↗

A splicing mutation in the alpha 5(IV) collagen gene of a family with Alport's syndrome.

DNA sequence analysis of the alpha 5(IV) collagen chain gene (COL4A5) was carried out between exon 47 and 51, which encode the noncollagenous (NC) domain, in eight Japanese families with Alport's syndrome. In one family with X-linked inheritance of the disease, a point mutation (G to C) was found at the 3' end of exon 49 in the COL4A5. This mutation converted the codon of a conserved methionine-1601 to the codon for isoleucine, and also altered the normal splicing process. The polymerase chain reaction (PCR) product amplified between exons 47 and 51 of cDNA in the affected male (hemizygote) of this family contained four fragments with various molecular weights, whereas that of a normal control contained one with the expected molecular weight. Sequence analysis of the PCR fragments of the male patient revealed various types of alternative splicing between the exons, reflecting the various sizes of PCR fragments. The PCR amplified product of the cDNA of the affected female (heterozygote), on the other hand, contained a fragment with the same molecular weight as the normal control. Sequence analysis of the PCR fragments of her cDNA revealed normal splicing and no point mutation at the 3' end of exon 49. These findings indicate that this point mutation at the consensus sequence not only converted the codon but also altered the splicing between these exons encoding the NC domain of the COL4A5. Resulting in missense of the alpha 5(IV) chain, changing a large portion of the carboxyl terminal crosslinking NC domain, this mutation can alter the normal structure of the type IV collagen network.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Treatment of severe pertussis by administration of specific gamma globulin with high titers anti-toxin antibody.

Our patient presented with severe respiratory distress and marked pleocytosis. She was mechanically ventilated and received gamma globulin with high titers of anti-pertussis toxin and anti-filamentous hemagglutinin. Her clinical signs improved and a notable decrease in white blood cell count was observed. Ten months after treatment, the patient showed normal physical and mental development and anti-pertussis toxin and anti-filamentous hemagglutinin titers were significantly increased. Recently, the effectiveness of gamma globulin therapy has been emphasized again. Our experience supports the use of iv gamma globulin infusion. Also, gamma globulin did not influence the patient's own immunologic response to pertussis. Gamma globulin therapy with high anti-pertussis toxin titers could be considered for treatment of severe pertussis.

Antitoxins↗