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Y Murai

Publications and source records attributed to Y Murai.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Frontal distribution of early cortical somatosensory evoked potentials to median nerve stimulation.

The topography of early frontal SEPs (P20 and N26) to left median nerve stimulation was studied in 30 normal subjects and 3 patients with the left frontal bone defect. The amplitudes of P20 and N26 were maximum at the frontal electrode (F4) contralateral to the stimulation and markedly decreased at frontal electrodes ipsilateral to the site of stimulation. There was, however, no latency difference of P20 and N26 between ipsilateral and contralateral frontal electrodes. These results suggest that the origin of the ipsilateral and contralateral P20 and N26 is the same. The wide distribution of P20 and N26 over both frontal areas could be explained by assuming a smearing effect from generators actually located in the rolandic fissure and motor cortex.

Adult↗
PubMedDate not supplied

Topography of somatosensory evoked potentials to median nerve stimulation in patients with cerebral lesions.

Scalp distributions and topographies of early cortical somatosensory evoked potentials (SEPs) to median nerve stimulation were studied in 22 patients with 5 different types of cerebral lesion due to cerebrovascular disease or tumor (thalamic, postcentral subcortical, precentral subcortical, diffuse subcortical and parieto-occipital lesions) in order to investigate the origins of frontal (P20, N24) and central-parietal SEPs (N20, P22, P23). In 2 patients with thalamic syndrome, N16 was delayed in latency and N20/P20 were not recorded. No early SEP except for N16 was recorded in 2 patients with pure hemisensory loss due to postcentral subcortical lesion. In all 11 patients with pure hemiparesis or hemiplegia due to precentral subcortical lesion N20/P20 and P22, P23/N24 components were of normal peak latencies. The amplitude of N24 was significantly decreased in all 3 patients with complete hemiplegia. These findings support the hypothesis that N20/P20 are generated as a horizontal dipole in the central sulcus (3b), whereas P23/N24 are a reflection of multiple generators in pre- and post-rolandic fissures. P22 was very localized in the central area contralateral to the stimulation.

Adolescent↗
PubMedDate not supplied

Cortical somatosensory potentials evoked by magnetic stimulation: effect of body height, age, and stimulus intensity.

Cortical somatosensory evoked potentials elicited by non-invasive magnetic stimulation at Th10, Th12, and L5 vertebral levels and at mid-gluteus and ankle were studied in 45 normal controls varying in body height and age. Peak latencies of P2 evoked by ankle, mid-gluteus and L5 stimulation were correlated with body height. However, P2 latencies evoked by Th10 and Th12 stimulation were independent of body height. In contrast, all N2 latencies evoked by Th10, Th12, L5, mid-gluteus and ankle were correlated with body height. There were no correlations between latencies of P3 and N3 and body height. No peak latencies of cortical components were affected by age within the age group studied (15-67 years). In the intensity study, N2 showed double peaks when low to moderate stimulus intensities were applied to Th12 vertebra. Furthermore, in 2 patients with mild somatosensory dysfunction of lumbar roots or cord, N2 evoked by L5 stimulation revealed double peaks with prolonged interpeak latencies between the first peak of N2 and P3, which might be related to the temporal dispersion of the afferent fibers. These data suggest that the N2 component is induced by both fast and slow afferent fibers.

Adolescent↗
PubMedDate not supplied

Autopsy cases of asbestosis in Japan: a statistical analysis on registered cases.

There are 525 (484 male, 38 female, 3 unknown) autopsy cases with asbestosis registered in the Annual of the Pathological Autopsy Cases in Japan, which is issued by the Japanese Society of Pathology for the years 1958-1996. The frequency of asbestosis (number of cases/total autopsy cases) was 0.017% (76/440,334) for the 1958-1979 time period, 0.058% (226/390,124) for 1980-1989, and 0.099% (223/225,801) for 1990-1996. There was a significant increase in asbestosis cases across the three time periods (p < .0001). The number of asbestosis cases increased markedly among individuals who worked with asbestos products, as well as among those employed in asbestos-processing factories. The frequency of malignant tumors associated with asbestosis was 61.0% (320/525), and the frequency also increased across the three time periods, from 43.4% (33/76) to 62.8% (142/226) and 65.0% (145/223), respectively. Among the 525 cases with asbestosis, there were 174 lung cancers (33.1%), 73 malignant mesotheliomas (13.9%), 29 stomach cancers (5.5%), 14 liver cancers (2.7%), 9 prostatic cancers (1.7%), 8 malignant lymphomas (1.5%), 6 laryngeal cancers (1.1%), 4 pancreas cancers (0.8%), 3 rectal cancers (0.6%), and 28 other cancers (5.3%). The frequencies of lung cancer, malignant mesothelioma, and laryngeal cancer were significantly higher in the cases with asbestosis than among the nonasbestosis cases. The number of malignant tumors related to asbestos exposure is expected to increase in the future.

Adult↗
PubMedDate not supplied

Malignant mesothelioma in Japan: analysis of registered autopsy cases.

In the Annual of the Pathological Autopsy Cases in Japan, issued by the Japanese Society of Pathology from 1958 to 1996, a total of 1,846 (0.17%) malignant mesothelioma cases (1,287 male, 558 female, 1 unknown) were registered among 1,056,259 autopsy cases. The frequency of mesothelioma (number of cases/total autopsy cases) was 0.10% (461/440,334) for the term 1958-1979, 0.18% (716/390,124) for 1980-1989, and 0.30% (669/225,801) for 1990-1996; the frequency of cases increased significantly over the time periods (p < .0001). Among 1,785 cases for which tumor sites were ascertained, there were 1,213 pleural mesothelioma (68.0%), 431 peritoneal (24.1%), 108 pericardial (6.1%), 6 tunica vaginalis testis (0.3%), and 28 "others" (1.6%). Histological cell type was noted in 598 cases; 245 (41.0%) were epithelial, 168 (28.1%) were biphasic, and 185 (30.9%) were sarcomatous. Seventy-three (0.007%) cases of malignant mesothelioma with asbestosis were found during the entire 39-y period. The frequency of those with asbestosis (number of cases/total autopsy cases) was 0.001% (5/440,334) for the term 1958-1979, 0.006% (27/390,124) for 1980-1989, and 0.018% (41/225,801) for 1990-1996; this increase over time was statistically significant (p < .0001). Researchers expect that cases of asbestos-related mesothelioma will increase in Japan in the future. Tumor sites and histological cell types of mesothelioma with asbestosis did not differ from those in individuals without asbestosis.

Adolescent↗
PubMedDate not supplied

Propylene oxide causes central-peripheral distal axonopathy in rats.

In Wistar rats subjected daily to a 6-hr exposure of propylene oxide (PO) at a concentration of 1,500 ppm (5 times a wk for 7 wk), ataxia developed in the hindlegs. Myelinated fibers in hindleg nerves and in the fasciculus gracilis showed axonal degeneration, sparing the nerve cell body of the first sacral dorsal root ganglion and myelinated fibers of the first sacral dorsal and ventral roots. These pathologic findings are compatible with central-peripheral distal axonopathy. This is apparently the first animal model of PO neuropathy to be verified histologically.

Air Pollutants↗
PubMedDate not supplied

Asbestos fiber analysis in seven asbestosis cases.

Asbestos bodies and fibers deposited in the lungs of seven asbestosis cases were counted after tissue digestion. The types and sizes of 100 asbestos fibers for each case were also analyzed. Asbestos bodies were counted with an optical microscope at 100x magnification, and asbestos fibers were counted with a transmission electron microscope (TEM) at 2000x magnification. Most asbestos fibers detected with TEM were longer than 3 microns (92.5%) and thicker than 0.1 microns (92.3%). Short fibers less than 2 microns--both chrysotile and amphiboles, as well as long, thin fibers less than 0.06 microns--would be missed at 2000x (TEM). An average of 1.37 (0.081-5.5) x 10(6) asbestos bodies and 164.8 (0.55-610) x 10(6) asbestos fibers per 5 g wet (0.88 g dry) lung tissue were found, and these values are higher than what was reported in mesothelioma cases without asbestosis that were reported previously. More than 13 (average = 266.2) asbestos bodies were found in a 4-micron-thick tissue section (average area = 3.24 cm2). One asbestos body in a section equaled approximately 5,000 per 5 g wet lung tissue. The intensity of fibrosis was minimal in one case, mild in four, moderate and severe in one each, and the intensity was correlated with the number of asbestos bodies and fibers. The fibrosis in the severe case may have been intensified by repeated infection. Crocidolite fibers were found most frequently (84.7%), were thin, and had a high aspect ratio by our counting rules. Crocidolite with a high aspect ratio may be most fibrogenic in the lung.

Adult↗
PubMedDate not supplied

Asbestos fiber analysis in nine lung cancer cases with high asbestos exposure.

We examined the types and sizes of 100 asbestos fibers in lung tissue obtained from 9 lung-cancer cases (5 autopsy and 4 surgical) with more than 10(4) asbestos bodies per 5 g of wet lung tissue, asbestos bodies in histological sections, and the history of occupational asbestos exposure. Evaluation of asbestos fibers by transmission electron microscopy (2,000 x magnification) revealed that most fibers were longer than 3 microns (96%) and were thicker than 0.1 micron (93%). The analytical conditions we used enabled us to identify 99.7% of all asbestos fibers as being amphibole asbestos. Crocidolite fiber, which was found most frequently (73.1%), was the predominant type of fiber found in 8 of the 9 cases; crocidolite was followed by amosite (21.7%), which was the predominant type found in the remaining case. Crocidolite fibers were thin and had a high aspect ratio (mean diameter = 0.23 micron, mean aspect ratio [length/diameter] = 85.5). Amosite fibers were long, and they also had a high aspect ratio (mean length = 21.8 microns, mean aspect ratio = 66.4). It has been suggested that such fibers with a high aspect ratio are strongly carcinogenic to pulmonary parenchyma. Review of our previous and present data with respect to the ratio of amosite to crocidolite fibers in groups of subjects who had various diseases revealed that this ratio was relatively constant in some occupations. The more predominant fibers found were crocidolite in insulation workers and amosite in railroad workers. The ratio of amosite to crocidolite fibers should be considered in tissue-burden studies.

Adult↗
PubMedDate not supplied

Asbestos body formation in the human lung: distinctions, by type and size.

The fraction of fibers coated in a total of 3,800 asbestos fibers from 38 patients with disease related to asbestos (100 fibers per patient) was determined, according to asbestos fiber type and size parameters. Among the 3,800 fibers, 638 (16.8%) were coated and 3,162 were uncoated. All fibers were analyzed at 2,000 x magnification (lower limit of detection: 2 microns for length and 0.06 microns for diameter). The diameter of the totally coated fibers (28.4% of total bodies; 181/638) was not measured. The percentage of coated fibers varied with the asbestos type; it was 27.1% (335/1235) for amosite fibers, 16.0% (228/1423) for crocidolite, 6.6% (60/908) for tremolite or actinolite, 6.5% (14/214) for anthophyllite, and 5% (1/20) for chrysotile fibers. Most coated fibers were longer than 10 microns and had an aspect ratio (length/diameter) of more than 20. Approximately 60% of coated fibers had an aspect ratio of more than 100. The longer the fiber, the greater the percentage of coated fibers, regardless of diameter. The increase in the percentage associated with length was more marked in fibers with a smaller diameter; the percentage of coated fibers was, therefore, greater in fibers 30 microns or less in diameter. However, in fibers longer than 30 microns, the relationship to percentage of coated fibers was not as clear, and the diameter was less important. Accordingly, the fibers with high aspect ratios, particularly long fibers, tended to show asbestos body formation. The percentage of long fibers was highest in amosite, and the percentage of fibers with an aspect ratio of more than 100 was highest in amosite and crocidolite.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Fiber analysis in lungs of residents of a Japanese town with endemic pleural plaques.

The authors analyzed various types of fibers in lung-tissue samples, which were obtained from 50 cases (46 surgical resections and 4 autopsies) at Kumamoto-Minami Hospital in Matsubase, where the occurrence of pleural plaques is endemic. Lung cancer necessitated surgical resection in 44 cases. Eleven of the 50 cases were residents of Matsubase; 15 resided in the region around the town, where the frequency of pleural plaques was slightly higher; and 24 cases lived in a region with normal plaque frequency. The number of anthophyllite fibers in the lungs of town residents was significantly higher than in residents of the region with normal plaque frequency. In 6 cases, the authors found accompanying pleural plaques, and the anthophyllite fiber count in the lungs in these cases was significantly higher than in cases without plaques. In addition, the anthophyllite fiber counts in 2 cases with severe plaques were significantly higher in 4 cases with only mild plaques. These results suggested that anthophyllite fiber might be responsible for the increased prevalence of pleural plaques in Matsubase. Even though the anthophyllite fibers were quite long (mean length = 25.1 microm), the width of most anthophyllite fibers were thick (mean diameter = 0.84 microm). Therefore, the aspect ratio of anthophyllite (mean = 38.7) was lower than that of amosite (mean = 81.8), which, in a previous report, was found predominantly in cases of pleural mesothelioma. Perhaps these differences in fiber size are related to the strength of the carcinogenicity to the pleura.

Aged↗
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Genetic variation in ABCB1 influences paclitaxel pharmacokinetics in Japanese patients with ovarian cancer.

Paclitaxel, an antineoplastic agent used for the treatment of ovarian cancer, is metabolized by cytochrome P450 (CYP)3A4 and CYP2C8 and is excreted from cells by ATP-binding cassette (ABCB1) (multi-drug resistance [MDR1], P-glycoprotein). Expression of these proteins is regulated by pregnane X receptor (PXR). Although there are common genetic polymorphisms in the genes encoding these proteins, their effect on the clinical efficacy of paclitaxel is unclear. We therefore examined the relationship of the paclitaxel pharmacokinetics in 13 patients with ovarian cancer to polymorphisms in CYP2C8, CYP3A5, ABCB1, and PXR. We found high interindividual variability in the plasma concentrations of two metabolites, 6alpha-hydroxypaclitaxel and p-3'-hydroxypaclitaxel. All the patients were genotyped as CYP2C8*1/*1. Neither the CYP3A5 A6986G (CYP3A5*3) nor the PXR C-25385T alleles were associated with altered plasma concentrations of paclitaxel and its metabolites. ABCB1 T-129C, T1236C, and G2677(A,T), however, was associated with lower area under the plasma concentration-time curve (AUC) of paclitaxel. We also observed a significant correlation between the AUC (r=-0.721) or the total clearance of paclitaxel (CL(tot)) (r= 0.673) and the ABCB1 mutant allele dosage in each patient. Taken together, our findings suggest that interindividual variability in paclitaxel pharmacokinetics could be predicted by ABCB1 genotyping.

ATP Binding Cassette Transporter, Subfamily B↗
PubMedDate not supplied

Serial somatosensory evoked potentials in a patient with familial hypobetalipoproteinemia, and vitamin E deficiency.

Serial somatosensory evoked potentials (SEPs) to median and posterior tibial nerve stimulation in a case with familial heterozygous hypobetalipoproteinemia and vitamin E deficiency were investigated over a period of 4 years. In serial SEPs to posterior tibial nerve stimulation, interpeak latencies between N20 and P2 were delayed even in the early clinical stage, although the peak latency of N20 was normal. N20 latency was delayed when the patient noted paresthesia of the lower extremities. Interpeak latencies between N20 and P2 were progressively prolonged, and finally both peaks disappeared. Progressive dysfunctions of spinal posterior columns and peripheral somatosensory pathways were discovered by serial SEP studies.

Cerebellar Ataxia↗
PubMedDate not supplied

[Clinical analysis of elderly patients with malignant lymphoma].

An epidemiological study on 173 consecutive elderly malignant lymphoma patients age 65 years or over was performed and the clinical outcome of chemotherapy is reported. Of there, 131 patients (75.7%) had non-Hodgkin's lymphoma (NHL) and 21 patients had Hodgkin's disease (HD). As for clinical staging, 58.9% of patients were in stage 3 or 4. The initial sites were nodal in 61.8% of the patients the most common sites of involvement in superficial lymph nodes being cervical, inguinal and axillar. The most frequent site of extranodal involvement was the gastrointestinal tract. The cases were treated with CHOP/COPP, BACOP or COP-BLAM combination chemotherapy. The clinical efficacy of these modalities was similar, with complete remission rates being about 50%. However, the total response rate (CR+partial remission) by the COP-BLAM regimen were 88.1%. The median survival time of cases achieving CR, was longer than 47 months. The most frequent cause of death was infection, especially pneumonia and septicemia. Many elderly ML patients were found and diagnosed when the disease developed to an advanced stage. Therefore it is necessary to make efforts to find early ML patients by screening apparently healthy elderly people. Improvement of the complete remission rate should be obtained if vigorous and intensive chemotherapy is carried out with careful supportive therapy concerning the general condition and complications in patients.

Age Factors↗