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Biomedical subjects

S Sakoda

Publications and source records attributed to S Sakoda.

At least 91 records · Page 5Linked to original sources
PubMed1995

Expression of the inducible isoform of nitric oxide synthase in the central nervous system of mice correlates with the severity of actively induced experimental allergic encephalomyelitis.

A cytokine-mediated excessive increase in nitric oxide (NO) by macrophages or glial cells via an inducible isoform of NO synthase (iNOS) has been proposed to play an important role in demyelinating diseases. To further investigate the role of iNOS in demyelination, experimental allergic encephalomyelitis (EAE), a known animal model of multiple sclerosis (MS) in mice, was chosen in this study. A semiquantitative reverse transcriptase-polymerase chain reaction (RT/PCR) analysis revealed an increase in the mRNA levels of iNOS and cytokines known to induce iNOS or inflammatory cytokines (interleukin (IL)-1 alpha, IL-1 beta, IL-2, IL-6, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha and TNF-beta) in the spinal cord corresponding to the severity of the disease without significant change in the mRNA levels of immunoregulatory cytokines (IL-4, IL-10 and transforming growth factor (TGF)-beta) during the course of EAE. An immunohistochemical examination of the spinal cord using an iNOS-specific antibody showed iNOS-positive cells to be mainly inflammatory cells with a higher frequency of iNOS-positive cells at the peak of EAE than in the early phase. These iNOS-positive cells at the peak appeared to be composed of infiltrating macrophages and most of them were located in the necrotic area. These results suggested that cytokine-induced excessive NO via iNOS by macrophages caused tissue damage in the central nervous system in EAE.

Animals↗
PubMed1995

Identification of human skeletal remains with a mandibular static bone cavity by comparison between ante- and post-mortem dental orthopantomograms: a case report.

We report a case of human skeletal remains in which a mandibular static bone cavity noted in a dental orthopantomogram assisted the positive identification. Unknown totally skeletonized human remains were found on a bushy slope of a hill. In the pockets of the clothing, there were a wooden seal, on which a family name was inscribed, and two cigarette lighters bearing the name of a bank. The body was identified as a male, about 50 years old. The estimated time elapsed since death was about six months to one year. No evidence of trauma was found in the clothing and the bones. The possible cause of death was due to poisoning from ingestion of bromvalerylurea (hypnotics). From the family name inscribed on the seal and the name of a bank on the cigarette lighters, the police investigation caught a missing man of 46 years old, who had last been seen alive about 6 months before. A dental orthopantomogram taken about 2 years before his disappearance was available for comparison. Eighteen days after recovery positive identification was practically accomplished based on unique features of the dental findings and a fairly rare, mandibular static bone cavity (a kind of bone cysts) by a X-ray comparison.

Bone Cysts↗
PubMed1994

Cloning and expression of myelin-associated oligodendrocytic basic protein. A novel basic protein constituting the central nervous system myelin.

We have screened genes predominantly expressed in the rat spinal cord, and we report here cloning of the most abundant unknown gene. It is a novel member of the central nervous system (CNS) myelin-constituting proteins, myelin-associated oligodendrocytic basic protein (MOBP). MOBP is abundantly expressed specifically in oligodendrocytes at the mRNA level only next to myelin basic protein (MBP) and proteolipid protein. Two isoforms have been confirmed. One of them has proline-rich tandem repeats and has 84% homology with human counterpart in terms of predicted amino acid sequences. The cDNA-derived primary structure predicts a small, soluble, basic protein. The immunoelectron microscopy has shown that MOBP is expressed throughout compact myelin. All these characteristics are similar to MBP. One definite difference between MBP and MOBP is that MOBP is expressed exclusively in the CNS myelin. These findings suggest that MOBP shares some important functions with MBP in the CNS myelin such as myelin compaction.

Amino Acid Sequence↗
PubMed1994

Isolation of a cDNA clone encoding a novel membrane protein expressed in lymphocytes.

By subtractive hybridization using single-stranded phagemids with directional inserts, we isolated a mouse cDNA clone, LSM-1, from temperature-sensitive Abelson virus-transformed immature B cells whose differentiation was being induced after the shift from the permissive (35 degrees C) to the non-permissive temperature (39 degrees C). LSM-1, which encodes an as yet unknown peptide of 197 amino acids, has a putative signal sequence and a trans-membrane region, and is expressed in B- and T-cell lines, in spleen, thymus, and bone marrow of adult mice, and in embryos.

Amino Acid Sequence↗
PubMed1994

Elevated expression of messenger RNA for peripheral myelin protein 22 in biopsied peripheral nerves of patients with Charcot-Marie-Tooth disease type 1A.

The human peripheral myelin protein 22 (PMP-22) gene has been mapped to chromosome 17p11.2 in the duplicated region associated with Charcot-Marie-Tooth disease type 1A. Southern blot analysis using PMP-22 as a probe indicated that the PMP-22 gene was duplicated in 5 patients from unrelated Japanese families with Charcot-Marie-Tooth disease type 1. In order to investigate whether or not an extra copy of PMP-22 has an effect on its gene expression, we analyzed relative expression of messenger RNA for PMP-22 and protein 0 (P0) against beta-actin by Northern blotting in biopsied nerves of the patients with type 1A disease, and compared the results with those of patients having other demyelinating neuropathies and the autopsied nerves of patients without neuropathies. The relative expression of PMP-22 messenger RNA in 5 patients with Charcot-Marie-Tooth disease type 1A was significantly higher than that in 5 patients with other demyelinating neuropathies (p < 0.05). There was no statistically significant difference in P0 expression between them. This study provided direct evidence for elevated expression of PMP-22 in peripheral nerves of patients with Charcot-Marie-Tooth disease type 1A as the result of a gene dosage effect. However, the relation between elevated expression of PMP-22 and the mechanism causing demyelination remains undetermined.

Adult↗
PubMed1994

Hereditary parkinsonism with multiple system degeneration: beneficial effect of anticholinergics, but not of levodopa.

Two siblings who exhibited hereditary parkinsonism with pyramidal signs and cerebellar ataxia are reported. Anticholinergics had a dramatic beneficial effect in both cases, but levodopa did not. This responsiveness, which is similar to that reported in patients with Joseph's disease, suggests dysfunction of an "indirect pathway" involving the globus pallidus and the subthalamic nucleus, in addition to that of the nigrostriatal system. We propose a new hereditary variant of early onset Parkinson's disease distinct from the levodopa sensitive forms of juvenile Parkinson's disease.

Adult↗
PubMed1994

[Transfer of multiple sclerosis into SCID mice].

Successful transfer of multiple sclerosis (MS) into severe combined immunodeficient (SCID) mice by intracisternal injection of cerebrospinal fluid (CSF) cells from six of 15 patients at exacerbation has been reported. The relative expression of mRNA for cytokines in demyelinated lesions from SCID-hu-MS by a semiquantitative reverse transcriptase-polymerase chain reaction analysis revealed marked increase in expression of mRNAs for TNF-alpha and IL-6. This result raised the possibility that these cytokines played an important role in the demyelinating process in SCID-hu-MS. To test whether or not an antibody (Ab) to murine TNF-alpha has a preventive effect on transfer of MS into SCID mice, intracisternal injection of CSF cells from two patients at exacerbation together with anti-murine TNF-alpha Ab was performed, and we observed effective prevention of transfer. In addition, we also found an Ab to human CD3 (OKT3) to have a preventive effect. The former result suggests that control of TNF-alpha may be effective in treatment of MS and the latter suggests that MS is a T cell-mediated disease.

Adolescent↗
PubMed1993

Neurosteroids in cerebrospinal fluid in neurologic disorders.

In order to investigate the role of "neurosteroids" in the central nervous system (CNS), cerebrospinal fluid (CSF) levels of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) were determined by radioimmunoassay in 57 patients with various neurologic disorders and 26 patients with non-neurologic disorders. The content of CSF DHEA and DHEAS in patients with Guillain-Barré syndrome (GBS), and the content of CSF DHEAS in patients with carcinomatous meningitis were significantly higher as compared to non-neurological control patients. These changes may be explained by the breakdown of blood-nerve barrier in these disorders. A significant positive correlation was observed between DHEAS and total protein in CSF. In males but not females, a negative correlation was observed between CSF DHEAS and aging. The level of CSF DHEAS, but not DHEA, was significantly higher in males than in females.

Adult↗
PubMed1993

Hormonal regulation of human testicular inhibin alpha and beta B subunit messenger RNAS.

Changes in messenger ribonucleic acids (mRNAs) of human testicular inhibin alpha and beta B subunits induced by human menopausal gonadotropin (hMG) and human chorionic gonadotropin (hCG) were assessed in vivo and in vitro. After a single administration of hMG, inhibin alpha mRNA in the human testis significantly increased, whereas inhibin beta B mRNA remained unchanged. Administration of hCG induced a slight increase in inhibin alpha mRNA without affecting inhibin beta B mRNA. In experiments in vitro using the testicular organ culture technique, an exposure to hMG for 24 hours induced a dose-related significant increase in inhibin alpha mRNA. Inhibin beta B mRNA was not affected by either hCG or hMG exposure. These results indicate that luteinizing hormone (hCG) as well as follicle stimulating hormone (hMG) may play a role in the regulation of human testicular inhibin alpha mRNA, although the mechanism of the LH action is not clear.

Adult↗
PubMed1993

[Genetics in movement disorders].

Genetic considerations in movement disorders are described. 1) Familial parkinsonisms are heterogeneous; genes for two of them, 'Lubag' and Waisman syndrome have been mapped to X chromosome, though genes for others do not have been mapped. 2) The responsible gene for Huntington's disease has been cloned recently and named huntingtin. A (CAG)n repeat longer than the normal range was observed in huntingtin gene. The (CAG)n repeat appears to be located within the coding sequence of a predicted approximately 348 kD protein that is widely expressed but unrelated to any known gene. The expansion of an unstable trinucleotide CAG repeat are also the causes of hereditary neurodegenerative diseases such as X-linked bular and spinal muscular atrophy and spinocerebellar ataxia type 1. 3) There are various forms in hereditary dystonia. Although the responsible gene for idiopathic torsion dystonia, inherited as an autosomal dominant pattern, has been mapped to 9q 32-34, genes for others do not have been mapped. 4) The Gilles des la Tourette syndrome (GTS) is a hereditary, neuropsychiatric-neurobehavioral disorder with childhood onset that is characterized by motor and vocal tics. About 80% of the human genome could be excluded as possible site for the GTS gene by studies with over 600 DNA markers in an international collaborative effort, but actual localization has not yet been accomplished.

Chromosome Mapping↗
PubMed1993

[A novel primer extension method to detect the number of CAG repeats in the androgen receptor gene in families with X-linked spinal and bulbar muscular atrophy].

X-linked spinal and bulbar muscular atrophy (SBMA), an adult-onset form of motor neuron disease, was recently reported to be caused by amplification of the CAG repeats in the androgen receptor gene. We report here a simple and rapid strategy to detect the precise number of the CAGs. After the DNA fragment containing the CAG repeats is amplified by the polymerase chain reaction, a primer extension is carried out; the extension of the end-labelled reverse primer adjacent to 3' end of CAG repeats stops at the first T after CAG repeats with the incorporation of dideoxy ATP in the reaction mixture. The resultant primer products are analysed by denaturing polyacrylamide gel electrophoresis and autoradiography. This method could be quite useful to detect not only CAG repeats in SBMA but also other polymorphic dinucleotide and trinucleotide repeats.

Adolescent↗
PubMed1993

The molecular genetic basis of muscle phosphoglycerate mutase (PGAM) deficiency.

The glycolytic enzyme phosphoglycerate mutase (PGAM) is a dimer, and mature human skeletal muscle contains almost exclusively the MM form of the enzyme, PGAM-M. In 1981, we identified a patient with PGAM-M deficiency, and three additional patients have since been described. All presented with exercise intolerance, cramps, and myoglobinuria. We report two new patients with PGAM-M deficiency and describe the molecular lesions in five patients--four African-Americans and one Caucasian. Three patients were homozygous for an identical G-to-A transition converting an encoded Trp to an in-frame stop codon (codon 78). A fourth patient was heterozygous for this mutation and also carried an A-to-C mutation converting Glu to Ala (codon 89). The fifth patient, the only Caucasian, was homozygous for a different point mutation, a C-to-T mutation, converting Arg to Trp (codon 90).

Adolescent↗
PubMed1992

Transfer of multiple sclerosis into severe combined immunodeficiency mice by mononuclear cells from cerebrospinal fluid of the patients.

To investigate the mode of the pathogenesis of multiple sclerosis (MS), we transferred cerebrospinal fluid (CSF) cells, predominantly mononuclear cells, from MS patients at both exacerbation and remission stages of the disease into severe combined immunodeficiency mice by intracisternal injection. As controls, (i) CSF cells from patients with cervical spondylosis and (ii) peripheral blood mononuclear cells from normal individuals were transferred. Four to 6 weeks after transfer, most mice transferred with CSF cells from MS patients at the exacerbation stage of the disease developed paralysis and ataxia. The histopathological examination on the sacrificed mice revealed multiple scattered, discrete lesions localized in the white matter of the brainstems and spinal cords. These lesions were characterized by various degrees of tissue necrosis, involving inflammatory-cell infiltration. Most infiltrating cells were macrophages, although a smaller number of granulocytes appeared in several foci. Reactive astrocytic gliosis was also seen around the necrotic foci. Furthermore, these lesions exhibited demyelination. These histopathological changes are similar to those seen in MS. In contrast, none of the severe combined immunodeficiency mice transferred with CSF cells from MS patients at the remission stage of the disease, or with CSF cells from the patients with cervical spondylosis, or with peripheral blood mononuclear cells from normal individuals showed any such histopathological changes. These observations provide convincing direct evidence of encephalitogenicity of mononuclear cells in CSF from MS patients at the exacerbation stage of the disease.

Animals↗
PubMed1992

A novel primer extension method to detect the number of CAG repeats in the androgen receptor gene in families with X-linked spinal and bulbar muscular atrophy.

X-linked spinal and bulbar muscular atrophy (SBMA), an adult-onset form of motor neuron disease, was recently reported to be caused by amplification of the CAG repeats in the androgen receptor gene. We report here a simple and rapid strategy to detect the precise number of the CAGs. After the DNA fragment containing the CAG repeats is amplified by the polymerase chain reaction, a primer extension is carried out; the extension of the end-labelled reverse primer adjacent to 3' end of CAG repeats stops at the first T after CAG repeats with the incorporation of dideoxy ATP in the reaction mixture. The resultant primer products are analysed by denaturing polyacrylamide gel electrophoresis and autoradiography. This method could be quite useful to detect not only CAG repeats in SBMA but also other polymorphic dinucleotide and trinucleotide repeats.

Adult↗
PubMed1992

A single MEF-2 site is a major positive regulatory element required for transcription of the muscle-specific subunit of the human phosphoglycerate mutase gene in skeletal and cardiac muscle cells.

In order to analyze the transcriptional regulation of the muscle-specific subunit of the human phosphoglycerate mutase (PGAM-M) gene, chimeric genes composed of the upstream region of the PGAM-M gene and the bacterial chloramphenicol acetyltransferase (CAT) gene were constructed and transfected into C2C12 skeletal myocytes, primary cultured cardiac muscle cells, and C3H10T1/2 fibroblasts. The expression of chimeric reporter genes was restricted in skeletal and cardiac muscle cells. In C2C12 myotubes and primary cultured cardiac muscle cells, the segment between nucleotides -165 and +41 relative to the transcription initiation site was sufficient to confer maximal CAT activity. This region contains two E boxes and one MEF-2 motif. Deletion and substitution mutation analysis showed that a single MEF-2 motif but not the E boxes had a substantial effect on skeletal and cardiac muscle-specific enhancer activity and that the cardiac muscle-specific negative regulatory region was located between nucleotides -505 and -165. When the PGAM-M gene constructs were cotransfected with MyoD into C3H10T1/2, the profile of CAT activity was similar to that observed in C2C12 myotubes. Gel mobility shift analysis revealed that when the nuclear extracts from skeletal and cardiac muscle cells were used, the PGAM-M MEF-2 site generated the specific band that was inhibited by unlabeled PGAM-M MEF-2 and muscle creatine kinase MEF-2 oligomers but not by a mutant PGAM-M MEF-2 oligomer. These observations define the PGAM-M enhancer as the only cardiac- and skeletal-muscle-specific enhancer characterized thus far that is mainly activated through MEF-2.

Animals↗