Biomedical subjects

S Murayama

Publications and source records attributed to S Murayama.

At least 19 recordsLinked to original sources

PubMed2005

Clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease.

BACKGROUND: No method for the clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease (sCJD) has been established except for pathologic examination. OBJECTIVE: To identify a reliable marker for the clinical diagnosis of MM2-type sCJD. METHODS: CSF, EEG, and neuroimaging studies were performed in eight patients with MM2-type sCJD confirmed by neuropathologic, genetic, and western blot analyses. RESULTS: The eight cases were pathologically classified into the cortical (n = 2), thalamic (n = 5), and combined (corticothalamic) (n = 1) forms. The cortical form was characterized by late-onset, slowly progressive dementia, cortical hyperintensity signals on diffusion-weighted imaging (DWI) of brain, and elevated levels of CSF 14-3-3 protein. The thalamic form showed various neurologic manifestations including dementia, ataxia, and pyramidal and extrapyramidal signs with onset at various ages and relatively long disease duration. Characteristic EEG and MRI abnormalities were almost absent. However, all four patients examined with cerebral blood flow (CBF) study using SPECT showed reduction of the CBF in the thalamus as well as the cerebral cortex. The combined form had features of both the cortical and the thalamic forms, showing cortical hyperintensity signals on DWI and hypometabolism of the thalamus on [18F]2-fluoro-2-deoxy-d-glucose PET. CONCLUSION: For the clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease, cortical hyperintensity signals on diffusion-weighted MRI are useful for the cortical form and thalamic hypoperfusion or hypometabolism on cerebral blood flow SPECT or [18F]2-fluoro-2-deoxy-d-glucose PET for the thalamic form.

14-3-3 Proteins↗

PubMed2005

Independent accumulations of tau and amyloid beta-protein in the human entorhinal cortex.

BACKGROUND: Previous studies have repeatedly described that neurofibrillary tangles arise earlier than senile plaques (SPs) in the entorhinal cortex, but one study suggested that SPs, if present, enhance the former lesions. All of these studies were performed at the histologic or immunocytochemical level, which may not accurately reflect the actual levels of amyloid beta-protein (Abeta) and tau. OBJECTIVE: To determine whether there is significant interaction between Abeta and tau in the human entorhinal cortex with regard to the Braak stage. METHODS: Biochemical studies were conducted on 50 brains from elderly people, who were mainly at Braak stages I to III. All the cases were examined neuropathologically and staged according to Braak and Braak. A small piece of brain tissue for each case was dissected from the anterior portion of the right entorhinal cortex. The amounts of tau and Abeta in the insoluble fraction of the tissue were quantified using western blotting. RESULTS: The levels of tau and possibly Abeta42 in the entorhinal cortex appeared to rise steeply at approximately age 75. The levels of insoluble tau increased as the Braak stage increased from I to II; however, it had a tendency to remain between stages II and III. The levels of Abeta42 showed a small increase, whereas those of Abeta40 increased continuously as the Braak stage advanced. In contrast, the extent of Abeta42 accumulation increased with increasing Braak stage for SPs. There was no significant correlation between the levels of insoluble tau and Abeta42 in the entorhinal cortex. Even if Abeta did not accumulate to significant extents, substantial accumulation of insoluble tau occurred. CONCLUSION: Accumulations of tau and amyloid beta-protein occur independently in the human entorhinal cortex.

Aged↗

PubMed2005

A multidisciplinary treatment strategy that includes high-dose chemotherapy for metastatic retinoblastoma without CNS involvement.

The prognosis of patients with metastatic retinoblastoma is poor with conventional chemotherapy and radiation. Since retinoblastoma is highly chemosensitive, dose-escalation of chemotherapeutic agents with stem cell support should be promising. We report our experience with high-dose chemotherapy (HDC) and autologous stem cell transplantation (SCT) in patients with metastatic retinoblastoma. Five patients with metastatic retinoblastoma underwent HDC with autologous SCT following conventional chemotherapy and local radiation therapy. Stem cells (bone marrow in four and peripheral blood stem cells in one) were collected after marrow involvement was cleared. Melphalan was a key drug in all patients, and was administered in combination with other agents such as cisplatin, cyclophosphamide, carboplatin or thiotepa. Three patients are currently alive disease-free at 113, 107 and 38 months, respectively, from the time of SCT. They had no central nervous system (CNS) involvement. The two patients who died of disease had CNS involvement. No long-term sequelae of HDC have been noted. Our treatment strategy using HDC appears to be effective for treating metastatic retinoblastoma without CNS involvement.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2005

Frequent importation of enterovirus 71 from surrounding countries into the local community of Yamagata, Japan, between 1998 and 2003.

Phylogenetic analysis of 45 enterovirus 71 (EV71) isolates for 6 years in Yamagata, Japan, clarified that the annual outbreak of hand-foot-and-mouth disease was due to four genetically distinct subgenogroups, including a novel "B5." Our results suggest that the importation of EV71 from surrounding countries has had a major epidemiological impact on the local community used in our study.

Capsid Proteins↗

PubMed2004

Clinical significance of elongation factor-1 delta mRNA expression in oesophageal carcinoma.

Elongation factor-1 (EF-1) delta is a subunit of EF-1, which is a protein complex that participates in the elongation step of mRNA translation and has recently been considered to correlate with oncogenic transformation. However, there has been no information regarding the clinical significance of EF-1 delta mRNA expression in malignant tumours, including oesophageal carcinoma. Thus, we quantitated the expression of EF-1 delta in malignant and benign oesophageal tissues and associated these levels with clinicopathologic parameters of oesophageal carcinoma. Paired oesophageal tissue samples from cancerous and corresponding noncancerous parts were obtained from 52 patients who underwent curative oesophagectomy. Quantitative analyses of EF-1 delta expression were performed using real-time quantitative reverse transcription-polymerase chain reaction. Elongation factor-1 delta mRNA overexpression in cancerous tissues compared to normal counterparts was observed in 38 of 52 (73%) patients. The mean expression level of EF-1 delta mRNA in cancerous tissues was significantly higher than that in noncancerous tissues (P<0.01). A higher expression of EF-1 delta was significantly correlated with lymph node metastases (P<0.05) and advanced stages (P<0.05). Furthermore, the cause-specific survival of patients with a higher expression of EF-1 delta was significantly poorer than those with a lower expression (5-year cause-specific survival rates; 23 and 54%, respectively, P<0.05). The results of this study indicated that EF-1 delta mRNA expression was significantly higher in cancerous compared to noncancerous oesophageal tissues, and a higher expression of EF-1 delta mRNA was correlated with lymph node metastases, advanced disease stages and poorer prognosis for patients with oesophageal carcinoma.

Adenocarcinoma↗

PubMed2004

Proteomics of the rice cell: systematic identification of the protein populations in subcellular compartments.

Despite recent progress in sequencing the complete genome of rice ( Oryza sativa), the proteome of this species remains poorly understood. To extend our knowledge of the rice proteome, the subcellular compartments, which include plasma membranes (PM), vacuolar membranes (VM), Golgi membranes (GM), mitochondria (MT), and chloroplasts (CP), were purified from rice seedlings and cultured suspension cells. The proteins of each of these compartments were then systematically analyzed using two-dimensional (2D) electrophoresis, mass spectrometry, and Edman sequencing, followed by database searching. In all, 58 of the 464 spots detected by 2D electrophoresis in PM, 43 of the 141 spots in VM, 46 of the 361 spots in GM, 146 in the 672 spots in MT, and 89 of the 252 spots in CP could be identified by this procedure. The characterized proteins were found to be involved in various processes, such as respiration and the citric acid cycle in MT; photosynthesis and ATP synthesis in CP; and antifungal defense and signal systems in the membranes. Edman degradation revealed that 60-98% of N-terminal sequences were blocked, and the ratios of blocked to unblocked proteins in the proteomes of the various subcellular compartments differed. The data on the proteomes of subcellular compartments in rice will be valuable for resolving questions in functional genomics as well as for genome-wide exploration of plant function.

Cell Membrane↗

PubMed2004

Surveillance of severe invasive group-G streptococcal infections and molecular typing of the isolates in Japan.

The number of patients with severe invasive group-G streptococcal (Streptococcus dysgalactiae subsp. equisimilis) infections has been increasing in Japan. The emm genotypes and SmaI-digested pulsed-field gel electrophoresis DNA profiles were variable among the strains isolated, suggesting there has not been clonal expansion of a specific subpopulation of strains. However, all strains carried scpA, ska, slo and sag genes, some of which may be involved in the pathogenesis of the disease.

Adhesins, Bacterial↗

PubMed2004

Epidemics of two Victoria and Yamagata influenza B lineages in Yamagata, Japan.

We attempted to predict epidemics of influenza B, focusing on B/Victoria/2/87-like (V) and B/Yamagata/16/88-like (Y) lineages, in Yamagata, Japan. We collected 9624 nasopharyngeal swabs for virus isolation from patients with respiratory infections between 1996 and 2003 and 237 sera for seroepidemiological analysis by haemagglutination-inhibition test in 2001. We isolated 424 V-lineage and 246 Y-lineage viruses during the study period. Three herald viruses in the 2000--2001 season enabled us to predict a V-lineage epidemic in the following season. However, another V-lineage epidemic occurred in the 2002--2003 season, although we caught four herald Y-lineage viruses, whose antigenic drift was suggested by seroepidemiological study, at the end of the previous season. Since the epidemiology of the two influenza B lineages remains unclear, a careful watch should be kept on these lineages in order to provide effective public-health strategies against future epidemics.

Adolescent↗

PubMed2004

Somatosensory-evoked fields for gingiva, lip, and tongue.

To localize the oral primary somatosensory cortex, we measured somatosensory-evoked fields for the lip, gingiva, and tongue in six healthy subjects. The latency of the first peak of the posterior-oriented current in the contralateral hemisphere was 50.9 +/- 8.3 ms for the gingiva, significantly shorter than those for the lip and tongue peaks. The equivalent current dipole was localized on the central sulcus. The gingival dipole was localized significantly inferior to the lip dipole but not different from the tongue dipole. The moment of the gingival dipole was significantly smaller than that of the lip dipole but not different from that of the tongue dipole. Differences in the above parameters were negligible between the left and right, anterior and posterior, and upper and lower locations within the same organ, except that the dipole location for the anterior upper tongue was significantly inferior to that for the lower tongue.

Adult↗

PubMed2003

Changing prevalent T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients in Japan.

We surveyed T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients. T1 (emm1) remained dominant through 1992 to 2000, but the dominant T3 (emm3.1) strains from 1992 to 1995 disappeared during 1996-2000. Strains of several emm genotypes emerged during 1996-2000, indicating alterations in the prevalent strains causing TSLS.

Antigens, Bacterial↗

PubMed2002

Spatial and temporal disease progression of adult-onset subacute sclerosing panencephalitis.

An adult-onset case of subacute sclerosing panencephalitis with occipitofrontal spread of the infection documented clinically and by MRI is reported. Autopsy revealed numerous intranuclear viral inclusions and widespread demyelination in both frontal lobes. In the occipital lobes where the disease started 5 years previously, inclusions were rare, but degenerative tissue changes were prominent. This case underlines the importance of measles virus migration for the progression of this fatal disorder.

Adult↗

PubMed2002

Early-onset, rapidly progressive familial tauopathy with R406W mutation.

An early-onset and rapidly progressive familial tauopathy with R406W mutation is described. The patient was a 47-year-old man who first presented with psychiatric symptoms followed by overt dementia at age 52 and died 1 year later. Postmortem study revealed tangle-associated neuronal degeneration, accentuated in the medial temporal lobe. R406W mutation was determined by sequence analysis and immunocytochemically with anti-mutant tau antibody.

Age of Onset↗

PubMed2002

Correlation of immunologic status with high-resolution CT and distributions of pulmonary tuberculosis.

PURPOSE: To investigate the correlation of cluster of differentiation (CD)4 lymphocyte counts with high-resolution CT (HRCT) findings and distribution of pulmonary tuberculosis. MATERIAL AND METHODS: Thirty-seven bacteriologically proven pulmonary tuberculosis, clinically non-AIDS, patients underwent HRCT and CD4 lymphocyte counts in peripheral blood cells were obtained within 3 days after the CT examinations. Patients were categorized into four groups according to CD4 lymphocyte counts (A >800; B 800-500; C 500-200; D <200). HRCT findings analyzed were as follows: typical, atypical, and mixed findings of post-primary tuberculosis, common, uncommon, and mixed distribution, and number of lobes involved. RESULTS: CD4 lymphocyte counts correlated with the degree of the mixture of atypical CT findings (rho=0.565, p<0.001) and the degree of the mixture of uncommon distribution (rho=0.431, p<0.01). Number of involved lobes showed no statistically significant correlation (rho=0.209, p=0.21). CONCLUSION: In patients with low CD4 levels, atypical HRCT findings co-exist with typical findings, and uncommon sites are involved in addition to common sites.

Adult↗

PubMed2002

Differential diagnosis between thymoma and non-thymoma by dynamic MR imaging.

PURPOSE: To evaluate the usefulness of dynamic MR imaging for differential diagnosis of anterior mediastinal tumors. MATERIAL AND METHODS: Fifty-nine patients with anterior mediastinal tumors were examined. According to histological diagnosis confirmed by surgery or biopsy, 31 had thymomas and 28 had non-thymoma lesions. The patients underwent dynamic MR imaging with gadopentetate dimeglumine administered as a bolus injection. Sequential images were obtained at 30-s intervals for 5 min. Significant differences in the mean peak times of time intensity curves (TICs) were found by histological type, using the Mann-Whitney test. RESULTS: The mean peak time of the TIC was 1.5 min in thymoma and 3.2 min in non-thymoma cases. The difference was statistically significant. Stages I and II of thymoma showed a mean value of 1.3 min, which was significantly shorter than that of 2.5 min in stage III. Differentiation of thymoma/non-thymoma based on the peak time of dynamic MR imaging showed optimal sensitivity (79%) and specificity (84%) when defining thymomas as lesions having peak time appearing earlier than 2 min and non-thymomas later than 2.5 min, with an accuracy of 81%. CONCLUSION: Dynamic MR imaging may improve the differential diagnosis between thymoma and non-thymoma and the staging of thymoma.

Adolescent↗

PubMed2001

Calpain-mediated degradation of p35 to p25 in postmortem human and rat brains.

Tau in Alzheimer neurofibrillary tangles has been shown to be hyperphosphorylated and CDK5, GSK3, MAP kinase and SAP kinases are the candidate kinases for the phosphorylation of tau. Recently, it was reported that the conversion of p35, the activator of CDK5, to p25 was upregulated in Alzheimer's disease (AD) brains, and that p35 is cleaved to yield p25 by calpain. Here we show that p35 is rapidly cleaved to p25 in rat and human brains within a short postmortem delay and that the conversion of p35 to p25 is partially dependent on calpain activity. Immunoblot analysis of brains prepared from patients with AD or age-matched control individuals with a short postmortem delay revealed no specific increase in the levels of p25 in AD brains, whereas the levels of active form of calpain were increased in AD brains compared to the those in controls. These observations suggest that the conversion of p35 to p25 is a postmortem degradation event and may not be upregulated in AD brains.

Aged↗

PubMed2001

Characterization of a wheat cDNA encoding mitochondrial ribosomal protein L11: qualitative and quantitative tissue-specific differences in its expression.

We have cloned a cDNA for a ribosomal protein of wheat that is similar to the bacterial ribosomal protein L11 (RPL11). To determine the subcellular localization of the gene product, we fused the whole cDNA sequence to the coding sequence for Green Fluorescent Protein, and expressed the fusion product transiently in epidermal cells of pea hypocotyls or dayflower leaves. Localized fluorescence was detectable in mitochondria, indicating that this nuclear cDNA encodes a mitochondrial ribosomal protein L11 (MRPL11). In lower protists, mitochondrial RPL11 is encoded by the mitochondrial genome, but higher organisms, including animals, fungi and plants, do not have genes for RPL11 in their mitochondrial genomes, suggesting that transfer of the genetic information for RPL11 from the mitochondrial genome to the nucleus was a very early event in evolution. Transcripts of this wheat gene (TaMRPL11) for mitochondrial RPL11 were found in all tissues examined, although qualitative and quantitative differences in expression were noted. The transcript sizes were different in different plant tissues: 1.0 kb in flowers and roots, and 1.5 kb in shoots. Cold stress transiently increased the steady-state level of TaMRPL11 mRNA in shoots, but the transcription of TaMRPL11 was completely inhibited by cold treatment for longer periods. However, the transcript level in flowers decreased gradually on exposure to low temperature. On the other hand, the accumulation of TaMRPL11 transcripts in roots was not affected by low temperature. These results suggest that the expression of MRPL11 in wheat is regulated precisely, in a tissue-specific manner.

Amino Acid Sequence↗

PubMed2001

Concurrent chemoradiotherapy for squamous cell carcinoma of thoracic esophagus: feasibility and outcome of large regional field and high-dose external beam boost irradiation.

OBJECTIVE: To assess the feasibility and outcome of concurrent chemoradiotherapy (CT-RT) with large regional field and high-dose external beam boost irradiation in thoracic esophageal cancer. METHODS: Patients with clinical stage T1 (submucosal)-4N0-1M0 (UICC 1997) squamous cell carcinoma of the thoracic esophagus were eligible. Radiotherapy consisted of regional irradiation (extending from supraclavicular fossa to the paracardial area) with 39.6 Gy followed by high-dose external beam boost up to 66.6 Gy (1.8 Gy/day, five times per week). Two-hour infusion of cisplatin (80 mg/m(2) on day 1) and continuous infusion of 5-fluorouracil (800 mg/m(2)/day on days 2-6) were administered concurrently with radiotherapy, every 3-4 weeks, for two cycles. RESULTS: Thirty patients (stage I, 3; stage II, 11; stage III, 16) were entered into the study. Twenty-one patients (70%) completed the planned treatment. In elderly (> or = 70 years) patients, four of six withdrew. Grade 3 and 4 toxicities (NCI-CTC) were observed in 20 (67%) and three (10%) patients, respectively. Major toxicities were blood, gastrointestinal (i.e. nausea and esophagitis) and pulmonary. There was no grade 5 (fatal) toxicity. The median follow-up period for surviving patients was 27 months (range: 9-49 months). The median survival time was 21 months. The 1- and 2-year survival rates were 65 and 49% for all 30 patients. The incidence of esophageal stricture (grade 1-2: RTOG) was 21%. No patient suffered fistula formation. CONCLUSIONS: Despite poor compliance for elderly patients and frequent severe toxicities, our concurrent CT-RT resulted in a favorable outcome in thoracic esophageal cancer.

Adult↗

PubMed2001

Relative biological effectiveness of the 235 MeV proton beams at the National Cancer Center Hospital East.

A therapy-dedicated cyclotron was installed in the National Cancer Center Hospital East (NCCHE) at Kashiwa in 1997. Prior to the start of clinical use, we investigated the biological effectiveness of therapeutic proton beams for cell lethality. The proton beams accelerated up to 235 MeV were horizontally extracted from the cyclotron, and scattered by a bar-ridge filter to produce a Spread-Out-Bragg-Peak (SOBP) of 10-cm width. The biological systems used here were mouse intestinal crypt cells and three in vitro cell lines, including SCC61 human squamous cell carcinoma, NB1RGB human fibroblasts and V79 Chinese hamster cells. The dose responses after irradiation at either the entrance plateau or the middle portion of SOBP were compared with those after linac 6 MV X-ray irradiation. The fit of a linear quadratic model to survival curves showed that proton irradiation increased the alpha value of SCC61 and the beta value of V79 cells with a least change for alpha/beta ratio of NB1RGB cells. The isoeffect dose that reduces either cell survivals to 10% or mouse jejunum crypts to 10 per circumference was termed D10. The relative biological effectiveness (RBE) of protons obtained by comparing the D10 values between protons and X-rays ranged from 0.9 to 1.2. The depth distribution of cell lethality was measured by replating V79 cells after irradiation from a "cell stack chamber" that received a single dose of 7 Gy at the middle position of SOBP. The thus-obtained cell survivals at various depths coincided well with the estimated survivals, but tended to decrease at the distal end of SOBP. We conclude that an RBE of 1.1 would be appropriate for 235 MeV proton beams at the NCCHE.

Animals↗