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Biomedical subjects

R Minami

Publications and source records attributed to R Minami.

At least 55 records · Page 3Linked to original sources
PubMed1998

Characterization and interpretation of the quantum efficiencies of multilayer semiconductor detectors using a new theory.

On the basis of a new theory of semiconductor X-ray detector response, a new type of multilayer semiconductor detector was designed and developed for convenient energy analyses of intense incident X-ray flux in a cumulative-current mode. Another anticipated useful property of the developed detector is a drastic improvement in high-energy X-ray response ranging over several hundred eV. The formula for the quantum efficiency of multilayer semiconductor detectors and its physical interpretations are proposed and have been successfully verified by synchrotron radiation experiments at the Photon Factory. These detectors are useful for data analyses under strong radiation-field conditions, including fusion-plasma-emitting X-rays and energetic heavy-particle beams, without the use of high-bias applications.

Journal Article↗
PubMed1998

Correlation between the M and F wave characteristics and the innervated muscle strength in spinal muscular atrophy.

The purpose of this study is to elucidate the interrelation between the M and F wave characteristics of the median nerve and the grip power in patients with spinal muscular atrophy (SMA). The SMA patients showed decreased amplitudes of the M and F waves, decreased frequency of the F wave, and an increase of the F/M ratio as compared with the normative values. The F wave frequency and the amplitudes of M and F waves, which showed a significant linear correlation with each other, became lower in accordance with the decrease of grip power. The properties of M and F waves strongly correlated with the number of surviving motor neurons which would be fewer in those severely affected by SMA.

Adolescent↗
PubMed1998

Phenotypic variability in a family with a mitochondrial DNA T8993C mutation.

Two patients are described in a family with a mitochondrial DNA T8993C point mutation. Patient 1, the proband, was a 4-year-old male, and his clinical features were consistent with those of Leigh syndrome, including lactic acidosis, motor development delay, and symmetric basal ganglia lesions on magnetic resonance imaging (MRI). His mental development was delayed mildly, but he has not demonstrated neurologic deterioration. Patient 2 was his maternal aunt. She developed her first neurologic sign at 18 months of age, thereafter her development ceased and regressed. She had lost her head control and become bedridden by 4 years of age and died at 20 years of age, demonstrating a more severe clinical course than that of Patient 1. Analysis of mitochondrial DNA from peripheral leukocytes of Patient 1 revealed a T8993C mutation of 99%. Patient 2 was demonstrated to have the same mutation at high abundance (99%) in the frozen myocardium and in the formaldehyde preserved spinal cord, with only 18% mutant mitochondrial DNA present in the formaldehyde preserved sciatic nerve. The mother of Patient 1, who was phenotypically normal (sister of Patient 2), had 35% mutant mitochondrial DNA in peripheral leukocytes. The authors' findings suggest that T8993C phenotypes are highly variable and that the proportion of the mutant mitochondrial DNA may vary among tissues and not correlate well with clinical severity.

Base Sequence↗
PubMed1998

Properties, sequence, and synthesis in Escherichia coli of 1-aminocyclopropane-1-carboxylate deaminase from Hansenula saturnus.

The plant hormone ethylene is generated from a unique precursor, 1-aminocyclopropane-1-carboxylate (ACC). In previous studies, ACC deaminase, which degrades ACC to alpha-ketobutyrate and ammonia, was found in four strains of Pseudomonas, characterized, and sequenced. To verify the wider distribution of ACC deaminase in microorganisms, we purified and sequenced ACC deaminase from the yeast Hansenula saturnus. The purified enzyme was active toward ACC, D-serine and dl-coronamic acid, indicating the same stereospecificity as the Pseudomonas enzyme, but unlike the bacterial enzyme it was not active toward beta-chloro-D-alanine and O-acetyl-D-serine. Analyses of peptides from proteolytic digests of the purified and modified ACC deaminase covered more than 90% of its amino acid sequence and showed a blocked N-terminal residue as N-acetylserine. A cDNA encoding the ACC deaminase was isolated from H. saturnus cells incubated in alpha-aminoisobutyrate medium, and sequenced. The yeast enzyme has 441 amino acid residues, of which 60 to 63% are identical to those of reported Pseudomonas enzymes. The open reading frame encoding ACC deaminase was subcloned into pET-11d and expressed in Escherichia coli BL21 (DE3) as an active enzyme.

Amino Acid Sequence↗
PubMed1998

Effects of aluminum hydroxide and famotidine on bioavailability of tosufloxacin in healthy volunteers.

This study was designed to determine the influence of aluminum hydroxide and famotidine on the bioavailability of tosufloxacin. Coadministration of aluminum hydroxide reduced the bioavailability of tosufloxacin by 31.6% (P < 0.05). Famotidine did not alter tosufloxacin absorption. To avoid potential treatment failures, the concurrent use of tosufloxacin and aluminum hydroxide should be avoided altogether.

Adult↗
PubMed1997

Codon 201Arg/Gly polymorphism of DCC (deleted in colorectal carcinoma) gene in flat- and polypoid-type colorectal tumors.

Recent studies have identified the distinct existence of flat-type colorectal tumors. The low incidence of ras gene mutations in these tumors suggests that their genetic pathways of tumor progression may be different from those of the polypoid type. To elucidate further genetic alterations in flat-type colorectal tumors, codon 201Arg/Gly polymorphism in the DCC (deleted in colorectal carcinoma) gene was analyzed in normal tissue (normal colonic mucosa or peripheral lymphocytes) and in tumor tissue from 191 patients with colorectal tumors (36 patients with flat-type colorectal tumors, 81 patients with polypoid-type colorectal tumors, and 74 patients with advanced carcinomas). For normal controls, 30 samples obtained from patients who had neither colorectal tumors (confirmed by total colonoscopy) nor a family history of colorectal carcinoma were analyzed. DCC gene codon 201Arg/Gly polymorphism was investigated by polymerase chain reaction-based restriction fragment length polymorphism analysis, fluorescence-based dideoxy sequencing, or both. For the flat type, the frequency of codon 201Gly of the DCC gene was 64% and 54% in the normal tissue of patients with adenoma with high-grade dysplasia and submucosal carcinoma, respectively. It was 49%, 52%, and 49% in the normal tissue of patients with polypoid-type adenoma with high-grade dysplasia, submucosal carcinoma, and advanced carcinoma, respectively. In the normal tissue, codon 201Gly of the DCC gene was more frequently observed in patients with flat-type adenoma with low-grade dysplasia (67%) than in those with polypoid-type adenoma with low-grade dysplasia (18%) or in normal controls (17%, P < 0.05, chi2 test). Codon 201Arg/Gly polymorphism in tumor tissues did not differ from that in the corresponding normal tissues, except for 10 cases of carcinoma with loss of heterozygosity (LOH). In carcinomas with LOH, preferential loss of the codon 201Arg allele was noted (9/10 cases). These results suggest that codon 201Gly of the DCC gene is not only associated with flat-type colorectal tumors, but that it may serve as a useful genetic marker for identifying groups at higher risk for colorectal cancer.

Carcinoma↗
PubMed1996

Truncated XPA protein detected in atypical group A xeroderma pigmentosum.

XPA protein from a patient with typical group A xeroderma pigmentosum (XP) and three atypical group-A XP patients were analysed. Immunoblot analysis of XPA proteins revealed that a typical group-A XP patient showed no XPA protein band, while a smaller, truncated XPA protein, which appears to be responsible for mid skin lesions and minimal neurological abnormalities, was detected in cells from three atypical group-A XP patients. Furthermore, the difference in the amount of truncated XPA protein correlated with the mildness of neurological manifestations in these three atypical group-A XP patients. The results suggest a correlation between clinical manifestations and qualitative and quantitative abnormalities of XPA protein products.

Adolescent↗
PubMed1996

Quantitative estimation of dystrophin protein: a sensitive and convenient "two-antibody sandwich" ELISA.

As dystrophin protein, the protein product of Duchenne muscular dystrophy (DMD) gene, represents only 0.002 approximately 0.03% of the total muscle proteins and human dystrophin protein has not been purified, quantitative estimation of this protein has been difficult. We describe a sensitive, reliable and convenient "two-antibody sandwich" enzyme-linked immunosorbent assay (ELISA) using commercially available monoclonal antibodies. This system, using a capture antibody specific for carboxyl terminus and two different detection antibodies for the mid-rod domain and the amino-terminal domain, is highly specific for dystrophin, since muscle specimens from DMD patients gave almost zero response (n = 3, 0.38 approximately 0.45%; expressed as a percentage of normal muscle tissue). This assay should prove to be an accessible and useful tool for the diagnosis of DMD/BMD and for the evaluation in clinical trials such as myoblast transfer and gene therapy.

Antibodies, Monoclonal↗
PubMed1996

[Structure and function of DCC (deleted in colorectal cancer) gene and its product].

The DCC gene is one of several genes altered during tumorigenesis. Recent studies demonstrate the existence of 29 exons and it spans 1.4 Mb. DCC gene is a candidate tumor-suppressor gene encoding a protein with a sequence similarity to cell adhesion molecule. Although the mutation of DCC gene was few, high incidence of LOH and decreased mRNA expression in colorectal cancer especially with hepatic metastasis was observed. These DCC gene abnormalities possibly be related to predictive marker for liver metastasis.

Amino Acid Sequence↗
PubMed1996

[A questionnaire study on health administration in small enterprises in a rural region].

A questionnaire study on the health administration of industrial workers was performed on 230 enterprises in city A in a rural region. Responding subjects numbered 140 and the response rate was 60.9%. Subjects by scale were: 16% with more than 50 workers, 48% with from 10 to 49 workers and 36% with less than 10 workers, and the proportions by industry were: 32% manufacturing, 22% wholesale-retail trade and 14% construction. The subject proportions classified according to the health insurance scheme were: 59% government-managed health insurance, 15% national health insurance and 11% society-managed health insurance. The rate of periodic health examination was 100% in enterprises with more than 50 workers, 67.2% in those with from 10 to 49 workers and 51.0% in those with less than 10 workers. The main reasons why then did not receive health examinations were: 40% had no time available to conduct examinations, 21% believed such examinations were not necessary, and 19% did not know of such an examination system. They encountered some difficulties in promoting health; for example, the advanced age of workers, and no time or money to spare for health administration. They desired provision of facilities close at hand for health examination, health consultation and health information. The results of this study show the difficulty of promoting health administration in small scale enterprises and also that it is difficult to obtain accurate information on actUal conditions including health administration in small enterprises.

Exercise↗
PubMed1995

[A boy with Emery-Dreifuss muscular dystrophy].

We reported a 12-year-old boy with Emery-Dreifuss muscular dystrophy (EMD). He was born after uncomplicated full term pregnancy and delivery. There was neither consanguinity nor a history of neuromuscular disorders or cardiac diseases in his family. He walked at 14 months. Toe walking was recognized at age 5 years. Examination at age 12 years showed the following. He could walk and climb stairs. There was no Gowers' sign. He had mild weakness of muscles except for face muscles. He had joint contractures at heels, elbows and knees. Deep tendon reflexes could not be elicited. Serum creatine kinase activity was significantly raised. Electromyography showed a myogenic pattern. Muscle biopsy from the left quadriceps showed mild dystrophic changes. 24 h Holter monitoring showed atrioventricular block with Wenckebach phenomenon. Prognosis in EMD is strongly connected with cardiac involvement. Therefore, we must follow up this case carefully for cardiac symptoms.

Biopsy↗
PubMed1995

[A case of severe Becker muscular dystrophy diagnosed in early childhood--correlation between clinical severity and dystrophin testing].

Since the 14kb human Duchenne muscular dystrophy (DMD) cDNA was cloned and its protein product "dystrophin" was discovered, immunochemical, biochemical and genetic analyses of dystrophin (dystrophin testing) have provided an accurate diagnosis of DMD/Becker muscular dystrophy in the clinical field. We performed dystrophin testing for a 5-year-old boy and confirmed he had severe BMD. Multiplex PCR of the DMD gene showed in-frame type deletion from exon 45 to 48. Immunohistochemical analysis of the muscle specimen obtained from the patient showed a discontinuous and patchy staining pattern, using monoclonal antibody that recognizes the C-terminus domain of dystrophin. On immunoblot analysis, we detected a faint band of 390 kDa. Dystrophin quantity was less than 10% of that compared to normal controls. The correlation between clinical severity and dystrophin testing was discussed.

Child, Preschool↗
PubMed1994

Identification of a novel first exon in the human dystrophin gene and of a new promoter located more than 500 kb upstream of the nearest known promoter.

The dystrophin gene, which is mutated in patients with Duchenne and Becker muscular dystrophies, is the largest known human gene. Five alternative promoters have been characterized until now. Here we show that a novel dystrophin isoform with a different first exon can be produced through transcription initiation at a previously unidentified alternative promoter. The case study presented is that of a patient with Duchenne muscular dystrophy who had a deletion extending from the 5' end of the dystrophin gene to exon 2, including all promoters previously mapped in the 5' part of the gene. Transcripts from lymphoblastoid cells were found to contain sequences corresponding to exon 3, indicating the presence of new promoter upstream of this exon. The nucleotide sequence of amplified cDNA corresponding to the 5' end of the new transcript indicated that the 5' end of exon 3 was extended by 9 codons, only the last (most 3') of which codes for methionine. The genomic nucleotide sequence upstream from the new exon, as determined using inverse polymerase chain reaction, revealed the presence of sequences similar to a TATA box, an octamer motif and an MEF-2 element. The identified promoter/exon did not map to intron 2, as might have been expected, but to a position more than 500 kb upstream of the most 5' of the previously identified promoters, thereby adding 500 kb to the dystrophin gene. The sequence of part of the new promoter region is very similar to that of certain medium reiteration frequency repetitive sequences. These findings may help us understand the molecular evolution of the dystrophin gene.

Amino Acid Sequence↗
PubMed1994

Amino-terminal deletion of 53% of dystrophin results in an intermediate Duchenne-Becker muscular dystrophy phenotype.

We report a Japanese boy with muscular dystrophy whose clinical symptoms were intermediate between those usually considered typical of Duchenne and Becker muscular dystrophies. The patient had a large inframe deletion extending from exons 3 to 41 of the dystrophin gene, which would be expected to cause the production of a dystrophin protein composing only 53% of the normal polypeptide chain. Such an inframe deletion would be expected to cause Becker muscular dystrophy. We did not obtain evidence for alternative splicing or for RNA editing. Immunocytochemical analysis of skeletal muscle showed that a dystrophin-related polypeptide was detectable with antibody directed against the carboxyl-terminal part of the polypeptide but not with antibodies directed against the amino-terminal part, although labeling by antibody against the carboxyl-terminal was faint and patchy. The severity of the disease in this case may be due to the lack of the amino-terminal, actin-binding domain of dystrophin.

Adolescent↗
PubMed1994

[A case of Larsen syndrome with severe cervical cord compression].

We reported a case of Larsen syndrome with cervical cord compression. She had a flattened face, bilateral joint dislocations of the elbows, hips and knees, and equinovalgus deformity on the feet. At first she had flaccidity of the upper and lower limbs, she gradually developed spastic. On laboratory examination, CSF protein was elevated. EMG showed fibrillation. In short latency somatosensory evoked potential (SSEP), N 20 was not detected. MRI showed a severe cervical cord compression. Cervical spine deformity has been often described in the previous reports on Larsen syndrome, but cervical cord compression demonstrated by MRI was reported in only one case. We should take into consideration this risk associated with Larsen syndrome.

Abnormalities, Multiple↗
PubMed1993

Effect of milk on absorption of norfloxacin in healthy volunteers.

The authors studied the effect of milk on the bioavailability of norfloxacin in six healthy male volunteers in a randomized crossover trial. After an overnight fast, 200 mg of norfloxacin was given with 200 mL of water or milk. Area under the curve (AUC) of norfloxacin with milk was significantly (P < 0.01) smaller than that with water. The mean peak serum concentration was decreased to 60% after oral administration of norfloxacin with milk (P < 0.01). The apparent volume of distribution at central compartment (Vc/f) value of norfloxacin was significantly (P < 0.05) increased with milk. Milk exhibits a clinically significant effect on norfloxacin absorption.

Adult↗