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Biomedical subjects

K Murakami

Publications and source records attributed to K Murakami.

At least 865 records · Page 48Linked to original sources
PubMed1990

Migration of bipolar subependymal cells, precursors of the granule cells of the rat olfactory bulb, with reference to the arrangement of the radial glial fibers.

In order to examine the relationship between radial glial fibers and the migrating bipolar subependymal cells which are considered to be post-mitotic precursors of granule cells in the rat olfactory bulb, the arrangement of radial glial fibers along the anterior lateral and olfactory ventricles was analysed by Golgi techniques, immunohistochemical demonstration of glial fibrillary acidic protein, and electron microscopy. In rats during their first 3 weeks of life, the bipolar subependymal cells migrate along the anterior lateral and olfactory ventricles into the center of the olfactory bulb, whereas the radial glial fibers radiating from the ventricular surface are arranged rather perpendicularly to the direction of migration of bipolar cells. Hence radial glial fibers in this region are not considered to act as guides for the rostralwards migration of subependymal cells.

Animals↗
PubMed1990

Structure of rice-straw arabinoglucuronoxylan and specificity of Streptomyces xylanase toward the xylan.

Rice-straw treated with 5% ammonia water was hydrolyzed with the beta-xylanase of Streptomyces sp. E-86, and four kinds of hetero-oligosaccharides, two arabinoxylo- and two glucuronoxylo-oligosaccharides, were isolated from the hydrolysate by charcoal column, gel filtration, ion-exchange, and aminopropyl silica column chromatographies. The structures of the oligosaccharides were identified as 3(2)-alpha-L-arabinofuranosyl-xylobiose, 3(2)-alpha-L-arabinofuranosylxylotriose, 2(3)-4-O-methyl-alpha-D-glucuronosylxylotriose, and 2(3)-alpha-D-glucuronosylxylotriose by the analysis of component sugar, partial acid hydrolysis, methylation analysis etc. Based on the structures of above oligosaccharides, the structure of rice-straw arabinoglucuronoxylan and the specificity of the xylanase toward the xylan are discussed.

Carbohydrate Conformation↗
PubMed1990

Secretion of Aspergillus oryzae alkaline protease in an osmophilic yeast, Zygosaccharomyces rouxii.

To produce Aspergillus oryzae alkaline protease (Alp) in an osmophilic yeast Zygosaccharomyces rouxii, we constructed an expression plasmid consisting of the Z. rouxii glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoter, the prepro-Alp cDNA of A. oryzae, the whole sequence of Z. rouxii plasmid pSR1, and the G418 resistant gene. The resulting plasmid, when introduced into Z. rouxii cells, directed the secretion of a large amount (about 300 mg/l) of Alp into the culture medium. The N-terminus and specific activity of the enzyme were identical to those of A. oryzae Alp.

Amino Acid Sequence↗
PubMed1990

Serum ascorbic acid and HDL cholesterol in a healthy elderly Japanese population.

The relationships between HDL cholesterol and serum ascorbic acid were examined in 79 male and 96 female healthy elderly Japanese, aged 60 and over. A significant positive correlation between serum HDL cholesterol and ascorbic acid was observed both in males (r = .243, p less than 0.05) and in females (r = .376, p less than 0.01). The results of multiple regression analyses indicated that serum ascorbic acid is a predictor of serum HDL cholesterol accounting for about 5% and 11% of its total variation in male and female subjects, respectively. The effect of age, BMI, status of physical activity, alcohol ingestion and cigarettes consumption, serum triglycerides and total cholesterol were taken into account as potentially confounding variables.

Aged↗
PubMed1990

Arthrographic evaluation of disk position following mandibular manipulation technique for internal derangement with closed lock of the temporomandibular joint.

The mandibular manipulation technique is widely used and is considered acceptable conservative therapy for an acute closed lock of the temporomandibular joint. However, there are no studies that prove objective morphologic assessment of this method in patients with unlocked disks. In this study, preoperative and postoperative arthrograms were evaluated to clarify the disk position in patients for whom successful mandibular manipulation was carried out. Postoperative arthrograms in 30 closed lock joints revealed that three joints were normal (complete reduction), eight had anterior disk displacement with reduction (click), 15 had partial reduction at the maximum mouth opening position, and four had anterior disk displacement without reduction. Disk mobility increased with improved condylar translation in all joints. These results indicate that complete anatomic reduction of the disk by mandibular manipulation is difficult, but also that clinical symptoms do not always correspond to how well the disk has been reduced by this treatment. Increasing disk mobilization might be effective treatment for patients with closed lock of the temporomandibular joint.

Adolescent↗
PubMed1990

[Histopathological studies of periodontal tissue reactions following apical plugging with autogenous dentin chips].

After treating the infected canals, we investigated to determine the influence of autogenous dentin chips accidentally applied as filling in the root apexes. Materials were 15 mandibular premolars and molars obtained from healthy, mature dogs. According to standard procedures, after pulp extirpation, canals were temporarily filled with sandarac cotton pellets and left otherwise untreated for 4 weeks. At this time, the degree of infection was ascertained. After root-canal enlargement, root canals were filled with No. 55 gutta-percha points; and a sealer (Neotriozinc Paste, AH26, or Sealapex) was applied. The animals were sacrificed at the conclusion of either a short term (2 weeks) or a long term (16 weeks), and histological studies were performed. Conclusions In short-term specimens, no formation of new hard tissue was observed at the apical dentino-cemental junction; and inflammatory changes in the periapical soft tissue were remarkable. In long-term specimens, hard-tissue formation had resulted in apical closure in 6 out of 8 instances; and periapical inflammatory changes had decreased. Relations between dentin-chip density and histopathological conditions were as follows: In most of the specimens that were evaluated as good, dentin chips were very densely applied. Insufficient numbers of dentin chips produced poor results. In other words, dense applications of dentin chips result in good prognoses. Consequently, when root-canal enlargement has been adequately performed, application of dentin chips to the apex of infected canals stimulates hard-tissue formation resulting in biological apical closure. In infected canals, however, the degree to which dentin chips are infected can be a major factor.

Animals↗
PubMed1990

[Flow cytometric cell cycle analysis of lymphocytes in patients with drug eruption].

DNA synthesis of lymphocytes was analyzed by flow cytometry in patients with drug eruption, eczema, viral eruption, and normal individuals. Lymphocytes were taken from the patients having fresh skin rash. In the patients with drug eruption, the percentages of lymphocytes in the G0G1 phase were lower and those in S + G2M phase were higher than the values in other groups, indicating the occurrence of blastogenic reaction. We considered that this method was helpful for diagnosis of drug eruption.

Adult↗
PubMed1990

[Huge splenic metastasis from hepatocellular carcinoma; a case report].

A 62-year-old man was admitted to the hospital because of a left upper quadrant mass. He had undergone treatment for hepatocellular carcinoma for 1 year and 7 months. Dynamic CT and angiography revealed a huge hypovascular mass in the spleen. An autopsy confirmed a splenic metastasis of hepatocellular carcinoma with a massive hemorrhage.

Carcinoma, Hepatocellular↗
PubMed1990

Identification and localization of epidermal growth factor and its receptor in the human glomerulus.

Radioimmunoassay for epidermal growth factor (EGF) was performed using the homogenates of glomeruli and tubular preparations obtained from normal human kidneys. EGF-immunoreactive material was 3- to 5-fold higher in the glomerular fractions than in the tubular fraction. By indirect immunofluorescence with a monoclonal antibody, EGF was positive in three of five normal human kidney tissues and in tissues of 24 of 33 patients with proliferative and nonproliferative types of glomerular diseases. Acid-urea treatment of tissue sections to unmask a hidden epitope of the EGF molecule disclosed EGF immunoreactivity in four more kidney specimens. EGF was localized along the glomerular capillary walls and was also present in the arterioles and small arteries. Staining with three monoclonal antibodies recognizing two different epitopes of EGF receptor (EGF-R) was positive in tissues of 2 normal subjects and 15 patients with glomerular diseases. EGF-R was found along the glomerular capillary walls, in peritubular capillaries, and within the epithelial cells of distal tubules and collecting ducts. Immunoelectron microscopy with colloidal gold staining showed that EGF and EGF-R were localized in the plasma membrane of glomerular endothelial cells. Immunofluorescence with or without acid-urea denaturation showed coexpression of EGF and EGF-R in glomeruli of 1 normal subject and 12 patients. This study demonstrated the presence of EGF and EGF-R in human glomeruli. There was no obvious difference in EGF and EGF-R expression in glomeruli derived from normal or diseased state.

Antibodies, Monoclonal↗
PubMed1990

[Qualitative and quantitative studies of synovial lesions in early rheumatoid arthritis demonstrated by immunocytochemistry with monoclonal antibodies].

We investigate the early stage of synovial lesions in 12 cases of rheumatoid arthritis (RA), which were diagnosed according to the criteria refined by America Rheumatism Association in 1987. The purpose of this study was to follow the inflammatory process from beginning to well known typical inflammatory features which are composed of a lot of lymphocytes and proliferated capillaries and the synovial cells. The characteristics of this study were that 1) the arthroscopy was applied for observation and getting synovial tissues, 2) 7 kinds of monoclonal antibodies were used for biopsied synovial tissues in immunohistochemistry study, further 3) qualitative and quantitative methods were adopted for identifying the infiltrating cells. These methods have developed recently in the fields of orthopaedics and immuno-histopathology, respectively. In very early stage, first, HLA/DR positive cells with large elongated cytoplasm accompanied but a few processes were found in pericapillary regions. These were neither macrophages nor lymphocytes. Following them T lymphocytes appeared and B lymphocytes appeared to aggregate in later. Quantitatively the number of HLA/DR positive cells including macrophages, B lymphocytes and a part of T lymphocytes and of Interstitial cells, increase and occupied the fairly large number of ratio in the cells of synovial tissues in RA.

Adult↗
PubMed1990

[Impairment of erythrocyte anti-oxidant defense mechanisms in hypoxemic patients].

Defense mechanisms against lipid peroxidation were studied in erythrocytes from hypoxemic patients. The levels of lipid peroxides in patients erythrocytes were higher than those of control subjects (15.3 +/- 10.9 vs 7.5 +/- 3.0, p less than 0.05). The levels of reduced glutathione (GSH) decreased in erythrocytes from the patients (426 +/- 108 vs 756 +/- 201, p less than 0.01). Activities of glutathione peroxidase (GPX) and superoxide dismutase (SOD) were lower than those of control subjects (GPX; 27.6 +/- 7.1 vs 35.1 +/- 3.8, SOD; 76.6 +/- 42.9 vs 125.7 +/- 40.1, p less than 0.01). Positive correlations were observed between the levels of arterial oxygen pressures (PaO2) and the GSH concentrations, the activities of GPX and SOD, respectively. These data suggest that decreased anti-oxidant activity enhances lipid peroxidation in erythrocytes from hypoxemic patients.

Aged↗
PubMed1990

[Three adult intussusception cases with colorectal cancer; CT diagnosis and its characteristic findings].

We have experienced three adult intussusception cases with colorectal cancer. In all three cases CT studies were performed prior to administering a barium enema, where we could make the exact diagnosis of the lesions in both the plain and the contrast studies. In the CT studies, the intussusception lesions showed the characteristic eccentric layered pattern. It was difficult to distinguish the tumors from the edematous intestinal walls at the proceeding portion in two cases. While in one case, the proceeding portion (the tumor itself) was pointed out as the enhanced soft tissue density mass of layered pattern with the irregular margins.

Aged↗
PubMed1990

[Efficacy of pancreatic scan--comparison among conventional scan, SPECT and X-CT].

We studied the efficacy of pancreas scintigraphy using 75Se-selenomethionine by conventional method and SPECT in 26 patients diagnosed as pancreatic tumor or pancreatitis. X-CT was also performed in all patients and compared its efficacy with that of scintigraphy. In order to evaluate the image quality, 4 doctors analysed the images independently without clinical information and score them according to the possible abnormality. The average score of each film was adopted as an index for sensitivity, and the standard deviation was evaluated as objectiveness of the images. As for the detection of pancreatic tumor, both the sensitivity and the objectiveness of X-CT were superior to those of scintigraphies. However, evaluation by scintigraphy combined with X-CT increased the diagnostic sensitivity of pancreatitis than that of X-CT alone in some cases. These results suggest that the scintigraphy has no indication to suspected pancreatic tumor, but it still has some value in limited cases of pancreatitis. Almost no advantage was noted in SPECT combined with conventional image. Main reason was the artifact of SPECT preventing the accurate interpretation. Only benefits of SPECT were to decrease the false positive rate and to increase the objectiveness of 75Se-selenomethionine scan. When the scan is discussed as the examination, careful considerations should be done on the point of limited advantage on diagnostic efficacy and marked disadvantage of radiation to patients and environment.

Adult↗