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F Soga

Publications and source records attributed to F Soga.

14 recordsLinked to original sources
PubMed1998

The fluid-attenuated inversion-recovery pulse sequence in assessment of central nervous system involvement in myotonic dystrophy.

We compared the fluid-attenuated inversion recovery (FLAIR) sequence with conventional spin-echo (SE) imaging for detection of involvement of the central nervous system in five patients with myotonic dystrophy (MD). The diagnosis was made based on clinical features and DNA analysis. All patients showed abnormal high-intensity lesions in the white matter on T2-weighted images, although these were more clearly visible using FLAIR.

Adult↗
PubMed1997

Analysis of relative biological effectiveness of high energy heavy ions in comparison to experimental data.

We report that the relative biological effectiveness (RBE) of accelerated heavy ions for inactivation of cells can be analyzed by using the quadratic dependence on the linear energy transfer (LET) of the cellular effect. For high-LET radiation in low-dose regions, the inactivation cross section (sigma) can be approximately expressed as sigma max [1-exp[-k.(LET/Li)2]; here, k is the number of heavy-ions traversed in a cell nucleus and Li is a geometrical parameter related to the DNA structure, which depends on cell type. This original expression was first presented by Powers et al [Int. J. Radiat. Biol. 14 (1968)]. Using this expression and the Poisson distribution for the stochastic property of particle hitting, the mortality of cell populations was calculated. The numerical results were compared to the RBE values recently obtained with Chinese hamster V79 cells, and an Lt value of 152 keV/micron was found to give the best fit. At LETs of between 30 and 500 keV/micron, the D10 values (10% survival dose) agreed with the experimental data within an error range of -15%-(+8%).

Animals↗
PubMed1996

Alzheimer-type pathology in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS).

A 53-year-old Japanese woman with a point mutation in mitochondrial DNA (tRNALeu(UUR), nt3243) consistent with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) and Alzheimer-type brain pathology is reported. This woman had suffered myopathy and psychosis without any clinical evidence of, stroke-like episodes during the last 10 years of her life, and had died after an accident. At autopsy 30 h post mortem, a part of the brain was snap frozen for biochemical and histochemical studies, and the remaining part was processed for a routine examination and electron microscopy. In the brain there were no ischemic lesions. Instead, primitive/diffuse senile plaques were found throughout the brain, predominantly in the frontal and temporal lobes, while Alzheimer neurofibrillary tangles were found only in the parahippocampal gyrus. These plaques were positive for beta-protein and mostly negative for tau protein, ubiquitin, neurofilaments, alpha-choline acetyltransferase, and acetylcholinesterase. Mutations in codon 331 of the ND2 gene as well as codons 693, 713 and 717 of the beta-amyloid precursor protein gene, known to be responsible for some cases of familial Alzheimer disease, were not found. Furthermore, coincidental Down syndrome was ruled out by chromosome analysis. The results suggest a possible correlation between this mitochondrial DNA abnormality and Alzheimer-type pathology.

Alzheimer Disease↗
PubMed1996

Decrease of the D3 dopamine receptor mRNA expression in lymphocytes from patients with Parkinson's disease.

We investigated the dopamine receptor (DAR) mRNA expression in peripheral blood lymphocytes from 45 patients with Parkinson's disease (PD) and 21 age-matched controls using the quantitative reverse transcription and polymerase chain reaction method. Beta-actin mRNA was used as an internal control to evaluate the relative expression level of the DAR mRNA. There was a statistically significant decrease of the D3 dopamine receptor (D3R) mRNA expression in PD patients compared with that in controls. There was no change in expression of the D5 dopamine reception mRNA in PD patients. A further binding study showed reduction of the D3R binding sites in PD lymphocytes. The decrease of the D3R mRNA expression correlated with the degree of clinical severity in PD patients.

Actins↗
PubMed1993

Expression of the D3 dopamine receptor gene and a novel variant transcript generated by alternative splicing in human peripheral blood lymphocytes.

The sequential reverse transcription and polymerase chain reaction amplified the mRNA coding for the D3 dopamine receptor (D3R) in human peripheral blood lymphocytes. Pharmacological analysis confirmed the binding of the D3R specific ligand to the lymphocytes. In addition, there was a novel shorter variant transcript of the D3R gene generated by alternative splicing in lymphocytes and brain. This variant, termed D3(TM4-del), has a 143 bp deletion and encodes a 138 amino acid protein containing the first three transmembrane domains of the native D3R.

Adult↗
PubMed1993

Dosimetry and measured differential W values of air for heavy ions.

Heavy-ion irradiation systems were designed and constructed at two cyclotron facilities in Japan for use in various fields of radiation physics and radiation biology. A 135 MeV/u carbon beam as well as 12 MeV/u carbon and helium-3 beams were first used in experiments. We have established a systematic method for heavy-ion dosimetry at both high and low incident energies involving measurements of fluences. We also obtained differential W values (w) of air for those beams by comparing the results of fluence measurement dosimetry with ionization chamber dosimetry. The differential W values of air were found to be 36.2 +/- 1.0, 34.5 +/- 1.0, and 33.7 +/- 0.9 eV for 6.7 MeV/u carbon ions, 10.3 MeV/u 3He ions, and 129.4 MeV/u carbon ions, respectively. The w value for high-energy heavy ions approaches the W value for high-energy electron or photon beams. In ionization chamber dosimetry for a heavy-ion beam, we found a track-size effect. A difference in the track sizes of heavy ions in the gas and solid phases affected the output current of the ion chamber in the case of high-energy heavy ions.

Carbon↗
PubMed1993

[Deletions of mitochondrial DNA in Kearns-Sayre syndrome].

Single large-scale deletions of mitochondrial DNA (mtDNA) are found in 70 to 80% of Kearns-Sayre syndrome (KSS) patients. Most deletions are flanked by direct repeats up to 13 nucleotides in length. The incidence of ragged-red fibers and cytochrome c oxidase-negative fibers in muscle is correlate with the amount of deleted mtDNA. Recently, study with 'cybrid' cell lines, which have different proportions of deleted mtDNA, showed that accumulation of deleted mtDNA to over 60% of the total mtDNA resulted in progressive inhibition of overall mitochondrial translation, as well as, reduction of cytochrome c oxidase activity. These results suggest that deletion of mtDNA alone is sufficient for the mitochondrial dysfunction in KSS.

Adult↗
PubMed1992

A novel mutant (transthyretin Ile-50) related to amyloid polyneuropathy. Single-strand conformation polymorphism as a new genetic marker.

DNA sequence polymorphisms in transthyretin (TTR) genes were investigated by single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction products. The amplified DNA fragments that encode each exon of the normal TTR gene showed two bands, representing the two complementary single strands of DNA. In one patient with amyloid polyneuropathy, the exon 3 DNA showed a unique, aberrant migration pattern. Direct sequencing analysis of the amplified exon 3 revealed a single base change (G-to-T), resulting in a novel amino acid substitution (Ser-50----Ile). We also present the SSCP patterns for five known Japanese TTR variants.

Amyloidosis↗
PubMed1991

[DNA tests for mutant genes coding for transthyretins Gly42, Arg50 and Cys114 in Japanese cases of familial amyloid polyneuropathy].

Four different genes encoding variant transthyretins (TTR) have been known in Japanese cases with familial amyloidotic polyneuropathy (FAP); TTR Met30, Gly42, Arg50 and Cys114. First three mutant genes can be detected by restriction fragment length polymorphism using NsiI, Cfr13I and MvaI, respectively. Since a single base change responsible for TTR Cys114 produces no new restriction site, RFLP is not directly applicable for the detection of this gene. In this study, TTR Cys114 gene was amplified by polymerase chain reaction using mismatch primer to produce a new restriction site for HgiAI. The enzyme digestion of the product resulted in the appearance of extra fragments in the presence of the normal fragment. The accurate detections of all the four mutant genes are hereafter possible by these procedures.

Amyloidosis↗
PubMed1990

Two novel variants of transthyretin identified in Japanese cases with familial amyloidotic polyneuropathy: transthyretin (Glu42 to Gly) and transthyretin (Ser50 to Arg).

Two mutant genes coding for two different variants of transthyretin were identified in two independent kindreds with familial amyloidotic polyneuropathy. A single base change from A to G was identified in exon 2 of transthyretin gene in two brothers from the first kindred. This base change led to replacement of glutamate by glycine at position 42 of 127-residue molecule. In a patient from the second kindred, T to G transversion in exon 3 of transthyretin gene led to replacement of Ser by Arg at position 50. The two mutants were discovered by randomly sequencing recombinant clones containing the entire length of each one of the four exons selectively amplified by polymerase chain reaction. The base change produced a new restriction site for Hae III and Cfr 13 I in the exon 2 and for Mva I in the exon 3, respectively. Restriction fragment length polymorphisms and allele-specific oligonucleotide hybridizations confirmed the base changes. The accurate detection of the new mutant genes is hereafter possible by these procedures.

Alleles↗
PubMed1989

[Two patients with cervical diastematomyelia].

Two patients with cervical diastematomyelia are reported here. A nineteen year-old-man (patient 1) admitted to our hospital because of muscular weakness of right upper limb. He noted muscular atrophy of right upper limb at 16 years old, and then paresthesia was gradually aggravated in the ulnar side of the right hand. Physical examination showed muscular atrophy of right upper limb and hypesthesia in the right eight cervical and first thoracic dermatomes. The deep tendon reflexes were decreased in the right upper limb and were increased in the lower limb without pathological reflexes. In electromyographic examination, neurogenic motor units were observed in the upper right limb, dominantly in 1st interosseous muscle (between the fourth cervical and the first thoracic dermatome). Metrizamide computed tomographic (CT) myelography revealed sagittal splitting of the spinal cord from the third to the sixth cervical vertebra, producing two asymmetrical hemicords. A osseous or fibrous septum were not seen. The right hemicord was smaller than the left one. Patient 2 was a twenty-four-year-old woman. She visited our hospital because of muscular weakness of the right upper limb. In physical examination, there were the muscular atrophy of right hand and hypesthesia in the right eighth and first thoracic dermatomes. The deep tendon reflexes were decreased in the right upper limb and were increased in the right lower limb without pathological reflexes. The EMG studies revealed the neurogenic NMU in the right upper limb (between the fourth cervical and the first thoracic dermatome). Magnetic resonance imaging showed marked narrowing of the dural sac in flexion of the neck.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Treatment of Kearns-Sayre syndrome with coenzyme Q10.

We studied the metabolism of coenzyme Q10 (CoQ) and the effects of CoQ therapy in five patients with Kearns-Sayre syndrome (KSS). Although the mitochondrial fraction was increased in muscles from KSS patients, CoQ content was slightly low. CoQ synthesis was normal in fibroblasts from KSS patients. Administration of 120 to 150 mg/d of CoQ improved abnormal metabolism of pyruvate and NADH oxidation in skeletal muscle. CoQ therapy decreased CSF protein concentration and CSF lactate/pyruvate ratio. ECG abnormalities and neurologic symptoms also improved.

Adult↗