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Biomedical subjects

M Tanimoto

Publications and source records attributed to M Tanimoto.

At least 163 records · Page 9Linked to original sources
PubMed1991

Direct carrier detection in hemophilia B kindreds: use of modified primers (mutagenic primers) for enzymatic amplification of the factor IX gene.

Rapid direct detection of point mutations in hemophilia B kindreds was performed by analyzing the restriction fragments of the factor IX gene amplified by polymerase chain reaction (PCR). The family members of the two patients, HB 5 and HB 6, whose mutant factor IX gene had previously been defined by sequence analysis, were examined in this study. Since there are no restriction endonucleases available for detecting each mutation directly, we designed modified primers which were substituted one nucleotide near the mutated positions. Following PCR with these primers, new Mbo I or Alu I cleavage sites for normal alleles were created. In each family, the restriction fragment revealed the carriership of each patient's mother. This simple methodology to detect mutations of interest is useful for genetic counseling in sporadic cases of hemophilia B.

Alleles↗
PubMed1991

Genotype establishments for protein C deficiency by use of a DNA polymorphism in the gene.

During the course of structural gene analyses for protein C deficiency, we have confirmed that a T or G nucleotide variation is present at exon 6 of the protein C gene. This single-base substitution was located at the third nucleotide coding for Ser (TCT) at 99 residue, and neither produces an amino acid substitution nor creates a new restriction enzyme site. By using mutagenic primers that could introduce A instead of G at the third nucleotide 3' to the de novo polymorphic site, we have created the polymorphic Xba I site (T/CTAGA) in a more-frequent allele. Polymerase chain reaction using these mutagenic primers and subsequent Xba I digestion of 20 normal Japanese genomic samples showed that the frequency of this new sequence polymorphism designated as PC-493 was 0.18 and that the estimated heterozygosity rate was 28.9%. In Caucasians, the frequency of this polymorphism was 0.25, and a significant difference did not exist between Japanese and Caucasian populations. The examination of the haplotype inter-relationships with PC-493 and the Msp I polymorphism 5' to the protein C gene established that PC-493 gave a 16.7% chance of new information per individual for people who were previously homozygous for the Msp I polymorphism. We have performed a family study of the protein C-deficient pedigree using this sequence polymorphism, and found that the PC-493 DNA polymorphism was a useful marker for tracing the affected gene in protein C-deficient family members.

Base Sequence↗
PubMed1991

Three distinct point mutations in the factor IX gene of three Japanese CRM+ hemophilia B patients (factor IX BMNagoya 2, factor IX Nagoya 3 and 4).

Enzymatic DNA amplification and complete sequence analysis were used to investigate human factor IX coding sequences in three CRM+ hemophilia B patients. In a patient with severe hemophilia B and a markedly prolonged ox-brain prothrombin time, a C to T transition in exon VI changed the codon for Arg180 to Trp (factor IX BMNagoya 2). This mutation would impair the cleavage by factor XIa required for activation of the zymogen. In a patient with mild hemophilia B, a G to A transition in exon VI changed the codon for Arg145 to His(factor IX Nagoya 3). This substitution also would be predicted to preclude the cleavage of factor IX by factor XIa at this peptide bond (Arg145-Ala146). Furthermore, this point mutation creates a new NlaIII restriction site which provides a quick and reliable method for carrier detection in the affected family members. A patient with severe hemophilia B (factor IX Nagoya 4) had a G to A transition in exon II changing the codon for Glu21 to Lys. This novel point mutation is assumed to impair the function of factor IX by disrupting the calcium binding of factor IX.

Amino Acid Sequence↗
PubMed1991

Induction of transplantable tumors by repeated subcutaneous injections of natural and synthetic vitamin E in mice and rats.

Natural vitamin E and synthetic vitamin E (dl-alpha-tocopheryl acetate) were tested for their tumorigenicity in rodents. Transplantable tumors, at the site of injection, were induced by repeated injections of these compounds in two strains of mice, NFS/N and C57BL/6N x C3H/He F1, and in a strain of rats, Fischer 344. Natural vitamin E was tumorigenic in both strains of female mice only when injected with soya oil. In contrast, dl-alpha-tocopheryl acetate alone was capable of inducing tumors in Fischer 344 rats. Only one out of 5 male NFS/N mice given dl-alpha-tocopheryl acetate developed a tumor. Therefore, Fischer 344 rats were more susceptible to tumor formation by dl-alpha-tocopheryl acetate than NFS/N mice. dl-alpha-Tocopheryl acetate with soya oil or with palm oil also resulted in the formation of transplantable tumors in NFS/N mice and Fischer 344 rats. There was no difference in the tumor incidence between mice treated with dl-alpha-tocopheryl acetate alone and dl-alpha-tocopheryl acetate plus soya oil or palm oil. However, in rats, the incidence was lower for a group treated with dl-alpha-tocopheryl acetate plus palm oil than for those with dl-alpha-tocopheryl acetate alone and with dl-alpha-tocopheryl acetate plus soya oil.

Animals↗
PubMed1991

Molecular species of phospholipid in rats in primary and transplanted fibrosarcomas induced by soybean oil containing tocopherol acetate.

When soybean oil containing tocopherol acetate was given to rats once a week subcutaneously for 10-12 months, it caused the development of fibrosarcomas at the injection site in 11 of 15 rats. A tumor produced in this manner proved eminently transplantable into other rats. The molecular species of phospholipid subclasses were determined in primary and transplanted tumors. The molecular species composition of the phospholipid subclasses in both types of tumors were similar. The percentages of diacyl and alkylacyl glycerophosphocholine (GPC) were 90-93 and 6-8% of total phosphatidylcholine, respectively. The percentages of diacyl and alkenylacyl glycerophosphoethanolamine (GPE) were 51 and 45%, respectively, of total phosphatidylethanolamine (PE). Diacyl and alkylacyl GPC species containing arachidonic acid (20:4) composed about 15-16 and 37-40% of each subclass, respectively. Diacyl and alkenylacyl GPE species containing 20:4 composed about 38-40 and 56-60% of each subclass, respectively. Disaturated species of diacyl and alkylacyl GPC composed about 22-24 and 13% of each subclass, respectively, whereas these species of PE composed less than 2%. The fatty acid composition of the other tumor phospholipids was analyzed.

Animals↗
PubMed1991

Choroid plexus metastasis of lung carcinoma--case report.

Metastatic tumors in the choroid plexus are generally considered to be very rare. The authors present a case of lung large cell carcinoma with a single metastatic tumor in the choroid plexus of the lateral ventricle trigone. Precontrast computed tomographic (CT) scans showed an isodensity mass with extensive peritumoral edema, which was considerably enhanced on the postcontrast CT scans. Magnetic resonance (MR) images demonstrated the mass as a low-intensity area on the T1-weighted image and an iso-intensity area on the T2-weighted image. The tumor was clearly differentiated from the peritumoral edema by both CT and MR imaging. The diagnosis was confirmed by surgery.

Carcinoma, Non-Small-Cell Lung↗
PubMed1991

Expression of H-related antigen on human megakaryocytes and megakaryocytic leukemia cells.

A mouse monoclonal antibody (MoAb), MG-2, was produced by immunizing a characterized human megakaryoblastic cell line, MEG-01. Since MG-2 reacted with erythrocytes of all ABH blood groups except Oh (O Bombay), and since anti-H MoAb inhibited MG-2 binding to MEG-01 cells, MG-2 is considered to recognize a molecule closely related to blood group antigen H. MG-2 reacted more strongly with normal smaller sized megakaryocytes than with larger sized ones, and not with platelets. The expression of the intrinsic H-related antigen on MEG-01 cells decreased concomitant to megakaryocytic differentiation induced by phorbol esters. This H-related antigen was expressed on leukemia cells with the megakaryocytic features from blast crisis of chronic myelogenous leukemia and acute megakaryoblastic leukemia.

ABO Blood-Group System↗
PubMed1991

[Possible mechanism of production of the musical second heart sound and its clinical significance].

To investigate the predisposing factors and the clinical significance of the musical aortic component of the second heart sound (musical S2), 18 patients with musical S2 (musical group) among the consecutive 2,000 patients with phonocardiographic examination were noninvasively studied by analyzing underlying diseases, phonocardiographic findings, organic changes of the aortic valve, severity of aortic regurgitation and left ventricular dysfunction. Organic changes of the aortic valve were assessed by two-dimensional echocardiography, and aortic regurgitation was assessed by color Doppler flow imaging. Twenty-two normal subjects (normal group) and 17 patients with essential hypertension (hypertensive group) served as controls. Mean ages were matched among the three groups. 1. Left ventricular dilatation (seven patients) and hypertension (six patients) were the dominant part of underlying disease in the musical group. 2. Musical S2 was classified in the following two types based on the phonocardiographic characteristics; musical vibrations followed immediately after the accentuated S2, and the S2 which was replaced by regular vibratory waves. 3. Frequency of the musical vibrations ranged from 120 to 200 Hz, and its duration ranged from 60 to 120 msec. Amplitude of the musical vibrations decreased by inhalation of amyl nitrite, but increased by infusion of methoxamine. In a case with mild rheumatic valve disease, methoxamine induced marked intensification of the amplitude and prolongation of the duration of the musical vibrations, finally giving a typical cooing murmur. 4. Echo intensity of the aortic valve tended to be higher in the musical group than in the other two groups. 5. Echocardiographically, aortic regurgitation appeared more frequently in the musical group (88%) than in the normal (36%) and hypertensive (41%) groups. Area of the aortic regurgitant signal was significantly larger in the musical group (4.1 +/- 1.4 cm2) than in the normal (1.2 +/- 0.8 cm2) and hypertensive (2.3 +/- 1.2 cm2) groups. 6. Left ventricular end-diastolic dimension was significantly larger in the musical group (5.8 +/- 0.6 cm) than in the normal (4.7 +/- 0.5 cm) and hypertensive (4.8 +/- 0.7 cm) groups. Fractional shortening of the left ventricle was significantly smaller in the musical group (26 +/- 10%) than in the normal (37 +/- 5%) and hypertensive (37 +/- 8%) groups. In a case of the musical group, musical vibrations following the S2, which was large in amplitude at the state of heart failure, decreased markedly after the recovery from heart failure.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1991

[Transesophageal echocardiographic study on systolic flow pattern of the pulmonary vein in patients with mitral stenosis and atrial fibrillation].

To determine the clinical significance and effect of cycle length on systolic backward (C) and forward (S) flow patterns of the pulmonary vein, we performed transesophageal and transthoracic echocardiography in patients with atrial fibrillation (Af). Study population consisted of 10 patients with mitral stenosis and sinus rhythm (MS-SR), 15 with MS and Af (MS-Af), 15 with mitral valve replacement and Af (MVR-Af), 10 with Af without organic heart disease (lone-Af) and 15 normal subjects. Various parameters, including peak velocities of C and S waves, closing amplitude of anterior mitral valve echogram during end-diastole, amplitude of the mitral annulus and interatrial septal motion during systole and left atrial pressure during the mitral closing period or end-diastole, were measured in each group. Results were as follows: 1. C wave was observed in all Af groups and six of 10 patients with MS-SR. Particularly, peak velocity of the C wave in MS-Af group was increased significantly compared with those of every other group. 2. Peak velocity of S wave in all Af groups, particularly in MS- and MVR-Af groups, decreased significantly compared with that of the normal group. 3. There were significant negative correlations between preceding R-R interval and peak velocity of the C wave or closing amplitude of anterior mitral valve echogram or left atrial pressure during end-diastole in MS-Af group. 4. There were significant positive correlations between preceding R-R interval and peak velocity of the S wave or amplitude of the mitral annulus or interatrial septal motion during systole in MS-Af group. 5. Peak velocities of the C and S waves had no correlations to preceding R-R interval in lone-Af group. We concluded that the C and S waves of pulmonary venous flow velocity pattern in MS-Af are affected by cycle length, and that the former is influenced by left atrial pressure and/or pliability of the mitral valve during the mitral closing period, and the latter by the grade of left atrial dilatation and/or preceding left atrial emptying.

Adult↗
PubMed1990

Enhanced expression of DNA topoisomerase II by recombinant human granulocyte colony-stimulating factor in human leukemia cells.

The effect of recombinant human granulocyte colony-stimulating factor (G-CSF) on DNA topoisomerase II (topo II) expression was studied in two human acute myelogenous leukemia cell lines, NKM-1 and NOMO-1, which express G-CSF receptor and proliferate in response to exogenous G-CSF. Northern blot analysis revealed that the level of topo II mRNA in 16-h stimulated cells in serum-free medium with G-CSF (10 ng/ml) was approximately 2-fold higher than that in cells without G-CSF. Enhanced topo II mRNA expression was detectable within 3 h after the addition of G-CSF. Topo II activity in crude nuclear extracts from 16-h G-CSF-stimulated cells was also found to be approximately 2-fold greater than that from unstimulated cells. According to in vitro cytotoxic assay, the sensitivity of G-CSF-stimulated cells to intercalating (daunorubicin) and nonintercalating (etoposide) topo II-targeting drugs increased significantly, whereas no enhancement of sensitivity was observed with an alkylating agent (4-hydroperoxycyclophosphamide). The augmented drug sensitivity observed was not due to the increased level of drug transport, as suggested by the similar extent of [3H]etoposide uptake between G-CSF-stimulated and unstimulated cells. By measuring the topo II mRNA and the cytotoxicity of the above mentioned drugs, we obtained essentially the same results in G-CSF-responsive leukemia cells isolated from three acute myeloblastic leukemia patients, as observed in the cultured cell lines. These findings strongly suggest that the sensitivity to "topo II-targeting drugs" could be augmented by exogenous G-CSF through elevated topo II activity in G-CSF-responsive leukemia cells.

Blotting, Northern↗
PubMed1990

DNA sequence analysis of three inhibitor-positive hemophilia B patients without gross gene deletion: identification of four novel mutations in factor IX gene.

Three hemophilia B patients with anti-factor IX antibodies who had no detectable gross deletion of the factor IX gene by Southern blotting analysis were investigated at the molecular level. All eight exons, accompanied by their splicing junction sites and presumptive promoter regions of the factor IX gene in these patients (total 5.5 kb in length) were amplified with the use of the polymerase chain reaction, followed by complete nucleotide sequence analysis. Three different types of novel single base substitutions and a 2 base-pair nucleotide deletion were identified. Patient HB-5 had two point mutations in his factor IX gene. One was located at the promoter region at nucleotide -793 and the other (C-to-T transition) was found in exon VI of the gene changing Gln-191 to a stop codon. Patient HB-6 had a point mutation (G-to-A) in the splice acceptor site, which interrupted the normal splicing of the last intron G. A small two-nucleotide deletion in exon III was detected in patient HB-7 and yielded frameshifted amino acids and terminated by a stop codon. These resuslts suggest that not only the gross gene deletion of factor IX gene but also the point mutations or small nucleotide deletion that may cause the interruption of coding informations for mature protein synthesis is predisposed to development of anti-factor IX inhibitors in patients with hemophilia B.

Autoantibodies↗
PubMed1990

[Molecular diagnosis of inherited coagulation disorders--sequence analysis of hemophilia B patients with anti-factor IX antibodies].

Seven hemophilia B patients with anti-factor IX antibodies are studied with molecular means. A total factor IX gene deletion was detected in four patients from three distinct families. Three other patients without detectable gene arrangements were investigated at the DNA sequence level. Enzymatic amplification of the factor IX gene and subsequent DNA sequencing revealed four novel nucleotide mutations in these patients. Patient HB 5 had two point mutations in his factor IX gene. One is located at nucleotide -793 from the translation start (G-A) and the other (C-T) was found in the codon for 191-Gln changing to a termination codon. Patient HB6 had a point mutation (G-A) in the splicing junction of intron g. A2 bp nucleotide deletion was detected in the third exon of the patient HB7 yielding 8 frameshifted amino acids and a stop codon. These results suggested that not only a large deletion of the factor IX gene but also point mutations or small deletion of the gene which may cause the substantial loss of the coding information for the mature protein are involved in the development of anti-factor IX antibodies in hemophilia B patients.

Antibodies↗