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Biomedical subjects

H Murata

Publications and source records attributed to H Murata.

At least 19 recordsLinked to original sources
PubMed1992

Shrinkage of tissue conditioners with time--effect of the particle size in powder and the EtOH content in liquid.

The dimensional change of tissue conditioners with time was measured until 4 weeks after mixing. Shrinkage of the materials was evaluated in relation to particle size in powder and the EtOH content in liquid. The dissolution of EtOH and plasticizer were also measured to investigate the relation to dimensional change. Shrinkage with time was recorded. The smaller the particle size in powder and the more EtOH in liquid, the greater the shrinkage rate. The smaller the particle size in the powder and the more EtOH contained in the liquid, the greater the dissolution of EtOH. The dissolution of BPBG was below 1/100 comparing that of EtOH and no difference was recognized by particle size and EtOH content. On the basis of these results it is suggested that the dissolution of EtOH is related to shrinkage of tissue conditioners with time and that the component particle size in the powder and EtOH content in the liquid have a significant influence on dissolution of EtOH associated with shrinkage.

Chromatography, Gas↗
PubMed1992

Genetic evidence for an activator required for induction of pectin lyase in Erwinia carotovora subsp. carotovora by DNA-damaging agents.

In Erwinia carotovora subsp. carotovora 71, the induction of pectin lyase (Pnl), the bacteriocin carotovoricin (Ctv), and cellular lysis (Lss) requires a RecA function. We obtained mutants wherein a pleiotropic defect, i.e., the lack of induction with mitomycin C, is not restored by the recA+ DNA. From a genomic library of strain 71, a cosmid (pAKC280) that restored induction of Pnl, Ctv, and Lss by mitomycin C was isolated. The activator function, designated Rdg for regulator of damage-inducible genes, was localized by subcloning and insertional mutagenesis to a 2.6-kb region within a 6.7-kb EcoRI fragment. An rdg-lacZ operon fusion was inducible by mitomycin C in RecA+ but not RecA- derivatives of E. carotovora subsp. carotovora 71 and Escherichia coli. A RecA+ E. coli strain carrying only a PnlA+ plasmid was not inducible for Pnl production; however, when both a PnlA+ plasmid and a Rdg+ plasmid were present, the transcription of pnlA and the production of the enzyme were activated by mitomycin C. The size of the pnlA transcript produced in E. coli was identical to that of the transcript produced by E. carotovora subsp. carotovora 71, suggesting that the same promoter and termination sequences were being utilized in these bacteria.

Bacteriocins↗
PubMed1992

Uncoupling action of antibiotic sporaviridins with rat-liver mitochondria.

The effects of the glycoside antibiotic sporaviridins (SVDs) on oxidative phosphorylation of rat-liver mitochondria were examined. SVDs released state 4 respiration, dissipated transmembrane electrical potential, and accelerated ATPase activity. These facts demonstrated that SVDs are potent uncouplers of oxidative phosphorylation. During the uncoupling caused by SVDs, large amplitude swelling and oxidation of intramitochondrial NAD(P)H occurred, suggesting that SVDs greatly enhanced nonspecific permeability of the inner mitochondrial membrane. It is suggested that the uncoupling action of SVDs might be caused by dissipation of proton electrochemical potential due to an increase in the permeability of inner mitochondrial membrane.

Aminoglycosides↗
PubMed1992

[Discrepancy between 123I-IMP SPECT and X-ray CT in chronic cerebrovascular disease].

The discrepancy between the low accumulation area (LAA) seen on 123I-IMP SPECT and the low density area (LDA) on X-ray CT was evaluated in 76 cases with chronic cerebrovascular disease. In 19 patients, LAA was larger than LDA beyond the vascular territory. Brain angiogram showed either obstruction or stenosis of the major arteries in as many as 59 percentages of this discrepancy group. In many patients of this group, cortical neurological symptoms were observed. In 37 patients in which the size of LAA was equal to that of LDA, abnormality of the major arteries was observed in only 7 percentages. These results indicated that the discrepancy mainly reflected the infarction due to irreversible ischemic change of perforate artery with the cortical low perfusion caused by the major artery disease. In some patients, the discrepancy was believed to show the remote effect caused by neurological pathway disturbance.

Adult↗
PubMed1992

[A case of true aneurysm of the mitral valve associated with torn chordae].

The patient was a 62 year old woman complaining of severe exertional dyspnea. Preoperative echocardiogram demonstrated the abnormal uniform echo of the anterior leaflet of the mitral valve which protruded toward the left atrium in systole as well as in diastole. Severe mitral regurgitation was also detected. The aneurysm of the anterior leaflet of the mitral valve was confirmed during the operation and mitral valve replacement was performed. The postoperative course was uneventful. Pathological examination of the resected aneurysm showed myxomatous degeneration. There were no signs of the inflammatory processes. The aneurysm formation in this case was considered to be due to the myxomatous degenerative changes of the anterior leaflet of the mitral valve. Fifteen cases of true aneurysm of the mitral valve reported in Japan were reviewed.

Chordae Tendineae↗
PubMed1992

[Reconstructive surgery in 59-year-old patient with coarctation of aorta under the monitoring of somatosensory evoked potential and spinal cord perfusion pressure].

Postoperative paraplegia is a relatively rare complication in reconstructive surgery for coarctation of the aorta and the operative treatment is usually performed without any adjuncts. A 59-year-old male patient underwent replacement of descending thoracic aorta with vascular prosthesis under the monitoring of SEP and spinal cord perfusion pressure (SCPP) [pressure difference between mean distal aortic pressure (MDAP) and the cerebrospinal fluid pressure (CSFP)]. During cross-clamping of the aorta, MDAP decreased from 61 to 40 mmHg and CSFP increased from 6 to 15 mmHg, SCPP was 25 mmHg, and the amplitude of the SEP waves rapidly decreased. As the ischemic changes of spinal cord were suspected, the aortic cross-clamping was released. The amplitude of SEP recovered to the preoperative level immediately after de-clamping. In order to prevent spinal cord ischemia, the partial cardio-pulmonary bypass was employed, and SCPP was maintained above 60 mmHg, so that SEP did not show any ischemic changes during cross-clamping of the aorta. The patient did not develop any neurological deficit postoperatively. The monitoring of SEP and SCPP appears to be useful for prevention of postoperative paraplegia in the surgical treatment for coarctation of the aorta.

Aortic Coarctation↗
PubMed1992

[Evaluation of I-123-BMIPP myocardial SPECT on the detection of ischemic heart disease by comparing with stress thallium-201 myocardial SPECT].

To evaluate the usefulness of I-123-BMIPP as a tracer of fatty acid metabolism in ischemic heart disease, we performed both rest BMIPP myocardial SPECT and stress thallium-201 (Tl) SPECT in 15 patients with prior myocardial infarction, and compared the segmental findings each other. The abnormality of BMIPP images was more intense than that of Tl redistribution images (Tl-RD) in more than 60% of the abnormal segments. The degree of myocardial uptake of BMIPP was more concordant with that of Tl stress scan (Tl-EX) than with that of Tl-RD. This agreement of the findings between BMIPP and Tl-EX was found more remarkably in the regions of incomplete Tl redistribution or in the collateralized regions. These results revealed that ischemia in the jeopardized regions was able to be detected even by rest BMIPP scan. Abnormal findings in BMIPP were observed in more than 95% of segments with persistent defects or incomplete redistribution in Tl, but observed in only 41 or 45% of segments with complete redistribution. Normal findings in BMIPP were observed in 94% of normal segments in Tl. From these results, we can speculate that abnormal regions in BMIPP may have necrotic or ischemic myocardial tissue and normal regions in BMIPP may not have necrotic tissue. These results suggest that I-123-BMIPP may be available to detect myocardial ischemia or infarction in the clinical study. Additionally, the difference in findings between the early images and the delayed images in rest BMIPP scan was observed with relatively high incidence (14% of regions and 73% of patients). More detailed analysis will be required to reveal the importance of this difference.

Aged↗
PubMed1992

[Immunohistological study of reactive follicular hyperplasia of lymph node in childhood].

Reactive follicular hyperplasia (RFH) of lymph nodes, which is often found in the peripheral nodes in children, is usually caused by viral, bacterial, or other specific infections, and sometimes complicated with dermatopathic lesions, or immunological disorders. Those nodal lesions might result from one of the various immunological reactions to some antigen. In this histologic and immunohistologic study, we mainly investigated the cells in the involved nodes. As the results, in the cases of the conspicuous follicular hyperplasia, there were prominent increase of the T-cell with positive UCHL1, the antigen presenting cells with positive S100 protein in T-nodule, and the B-cell with positive L26 in germinal center and cortical sinuses. The nodes with conspicuous follicular hyperplasia also showed foci of infiltration of the polymorphous leukocytes or the lysozyme positive mono-macrophages in the cortical sinuses at the early or acute stage. Decreasing the grade of RFH, the polymorphous or the macrophage infiltration disappeared, while S100 protein positive histiocytes remained as the persistent nodules or aggregates in the cortical sinuses. It was also noted that the B-cells with polyclonal surface immunoglobulins, IgM, kappa, or lambda, increased in number in the case of conspicuous RFH. The RFH might be the result of increased activity of the cellular and humoral immunity, with which T-cells, B-cells, antigen presenting cells, and mono-macrophages are concerned.(ABSTRACT TRUNCATED AT 250 WORDS)

Castleman Disease↗
PubMed1991

Direct interfacing of high-speed countercurrent chromatography to frit electron ionization, chemical ionization, and fast atom bombardment mass spectrometry.

Direct interfacing of analytical high-speed countercurrent chromatography (HSCCC) to mass spectrometry (MS) was demonstrated for the first time, and its performance was evaluated in terms of chromatography and mass spectrometry. HSCCC/MS interface was based upon Frit electron ionization (EI), chemical ionization (CI), and fast atom bombardment (FAB). Separations were conducted by newly developed HSCCC-4000 with a 2.5-cm revolutional radius and 0.3 mm or 0.55 mm i.d. multilayer coiled column which is capable of operating at a maximum speed of 4000 rpm. To demonstrate the potential capability of HSCCC/frit MS, three indole auxin mixtures, two mycinamicin (macrolide antibiotics) mixtures, and a colistin complex (peptide antibiotics) were analyzed under HSCCC/frit EI, CI, and FABMS conditions, respectively. The data obtained indicated that interfacing to frit/MS does not adversely affect the chromatographic resolution and mass spectra provide structural information. The HSCCC system interfaced with a frit-equipped mass spectrometer will offer a new dimension in the separation of biologically important substances.

Chromatography↗
PubMed1991

Clinical evaluation of endoscopic injection sclerotherapy for bleeding esophageal varices in liver cirrhosis with hepatocellular carcinoma.

Endoscopic injection sclerotherapy (EIS) for rupture of esophageal varices was carried out in 13 patients of liver cirrhosis with hepatocellular carcinoma (HCC). Sclerotherapy was performed by intravariceal injections of 5% ethanolamine oleate. According to the manual for the staging of cancer, these HCCs were classified as Stage I in 1 case, II in 1 case, III in 2 cases, and IV in 9 cases. There was no difference between post EIS prognosis and stage. Child's classification of these patients were class A in 1 case, B in 5 cases, and C in the remaining 7 cases. Only in 1 case of Child's A and 1 case of Child's B who were less advanced clinically and were free from icterus and ascites did EIS produce favorable results, it arresting esophageal variceal hemorrhage and led to a relatively good outcome. We suggest that emergency EIS for rupture of esophageal varices should be performed in patients with relatively good general conditions, irrespective of the stage of HCC.

Adult↗
PubMed1991

Detection of antibodies to hepatitis C virus (anti-HCV) in patients with various liver diseases, by an ELISA (KCL-163) test consisting of synthetic peptides corresponding to an HCV genome.

In 1989, the Chiron group developed an enzyme immunoassay system (C100) for detecting antibodies to hepatitis C virus (anti-HCV). In our examinations, the positive rate was 65.3% of the total number of patients (199) with non-A, non-B (NANB) liver disease. Additionally, a specific ELISA system (KCL-163) was developed by Kaketsuken (Kumamoto, Japan) based on synthetic peptides corresponding to an HCV genome of a Japanese isolate. In this study, we measured antibodies to HCV by KCL-163, and compared the results of KCL-163 with that of C100 in patients with various liver diseases. Our emphasis was on the discrepancies between the results of the two types of ELISA. We concluded that it was not sufficient to diagnose hepatitis C only by assay systems based on the C100-3 region of an HCV genome, and that KCL-163 was superior to C100 in its specificity and sensitivity in the diagnosis of hepatitis C.

Enzyme-Linked Immunosorbent Assay↗
PubMed1991

Availability and limitations of thallium-201 myocardial SPECT quantitative analysis: assessment as daily routine procedure for ischemic heart disease.

To determine the availability and limitations of the detection of ischemic lesions by stress thallium-201 myocardial SPECT as the daily routine procedure, we compared and evaluated the detectability of the quantitative analysis (%uptake and washout rate (WR)) and visual evaluation in 104 patients with effort angina and 17 normal subjects. Visual evaluation combined with WR analysis resulted in significantly higher sensitivity (88.0%) but lower specificity (60.2%) than the other methods. The sensitivity by visual evaluation was quite low in multivessel disease (MVD), and in the regions supplied by mild coronary stenosis or by the left circumflex artery. These were markedly improved by combining visual evaluation and WR analysis, but sensitivity in the MVD group was unsatisfactory even with this analytic method in comparison with the single vessel disease group. One of the causes of low sensitivity in the MVD group might be the "true negative": No induction of the ischemia in the regions of milder stenosis, or the regions supplied by the collateral coronary flow. We therefore conclude that the combination of visual evaluation as a qualitative analysis and WR analysis as a quantitative analysis, is the most useful daily routine procedure as a screening test for detecting ischemia.

Aged↗
PubMed1991

The use of omental pedicle flap for tracheobronchial reconstruction in infants and children.

For the surgical repair of long-segment tracheal stenosis, costal cartilage graft or extensive resection with end-to-end anastomosis has often been used. Both procedures have a risk of developing anastomotic leakage, which is potentially a lethal complication, or stenosis resulting from compromised blood supply to the tissue at the anastomosis. We have used omental pedicle flap (OPF) to seal the anastomotic line and to restore the vascularity of the graft and the trachea in an attempt to avoid fatal complications. During the period between 1986 and 1990, OPF technique was used in tracheobronchial reconstruction in six patients aged 4 months to 3 years; cartilage graft for extensive tracheal stenosis (4), tracheal resection and anastomosis (1), and bronchial resection and anastomosis (1). The omentum was separated from the colon to form an OPF with the right gastroepiploic vessels preserved. The OPF was brought to the upper trachea in the mediastinum through the retrosternal space. There was no immediate postoperative death due to anastomotic leak. Endotrachial tubes were removed in all patients. Four of the six are totally free of airway problems. One patient showed persistent stridor because of remaining stenosis at the cervical trachea. The remaining one patient who underwent bronchial resection developed anastomotic stenosis probably due to the compression of the floppy left main bronchus by adjacent aorta. The OPF seems to be an important surgical adjunct in order to eliminate fatal complications in tracheobronchial reconstruction.

Bronchi↗
PubMed1991

Isolation of two toxic heptapeptide microcystins from an axenic strain of Microcystis aeruginosa, K-139.

Two toxic heptapeptides were isolated from an axenic Microcystis aeruginosa strain, K-139. Using mainly a non-destructive NMR method, we determined the structure of the major toxin to be 7-desmethylmicrocystin LR which lacks an N-methyl group of the dehydroalanine moiety of microcystin LR. The minor toxin was deduced to be 3,7-didesmethylmicrocystin LR. The chromatographic and NMR analyses of 7-desmethylmicrocystin LR were compared with those of 3-desmethylmicrocystin LR.

Amino Acid Sequence↗
PubMed1991

Activation of bovine neutrophils by recombinant bovine tumor necrosis factor-alpha.

The in vitro effect of bovine recombinant tumor necrosis factor-alpha (rbTNF-alpha) on bovine neutrophil function and the possibility that rbTNF-alpha and recombinant bovine interferon-gamma (rbIFN-gamma) act synergistically were investigated. Treatment of neutrophils with rbTNF-alpha (0.05 micrograms/ml; approximately 50 U/ml) at 37 degrees C for 2.5 h resulted in enhancement of antibody independent neutrophil-mediated cytotoxicity (AINC) and inhibition of random migration and chemotaxis. The same treatment resulted in a slight decrease in iodination and cytochrome C reduction, but did not affect Staphylococcus aureus ingestion, or antibody dependent cell-mediated cytotoxicity. Kinetic and inhibitor studies indicated that the action of rbTNF-alpha was rapid and was independent of protein and RNA synthesis by neutrophils. Evaluation of the synergistic activities of rbTNF-alpha and rbIFN-gamma indicated that treatment of neutrophils with these two cytokines simultaneously resulted in additive enhancement of AINC and inhibition of random migration and chemotaxis. There was no additive effect of the two cytokines on inhibition of iodination or cytochrome C reduction.

Animals↗
PubMed1991

A case report of paroxysmal nocturnal hemoglobinuria in a child.

A ten-year-old boy with paroxysmal nocturnal hemoglobinuria (PNH) is described. Although hemolytic anemia was evident, Ham's test was negative and the erythrocyte acetylcholinesterase (ACHE) activity was normal at the first admission. The diagnosis of hemolytic anemia of unknown etiology was made. Methylprednisolone pulse therapy was started, but could not prevent the hemolytic crises associated with infections. Twelve months later Ham's test turned positive and ACHE activity decreased. The diagnosis of PNH was confirmed. As the disease is insidious in onset, we emphasize that a high index of suspicion and Ham's test and sucrose water test repeated at regular intervals are required to avoid missing the diagnosis.

Acetylcholinesterase↗
PubMed1991

Stunned myocardium and sympathetic denervation--clinical assessment using MIBG scintigraphy.

To evaluate the clinical relationship between stunned myocardium and the sympathetic nervous system, 6 patients who had stunned myocardium accompanied by T wave inversion underwent simultaneous 123I-metaiodobenzyl guanidine (MIBG) scintigraphy and thallium scintigraphy. All patients showed abnormal filling defects on the MIBG scintigrams in the areas with stunned myocardium but the thallium scintigrams were almost normal. The extent of the defects in these 6 patients was determined on the MIBG scintigrams using a Bull's eye display. The defects were found to be larger than those in 4 patients with angina pectoris, and those in 4 patients who had previously shown T wave inversion but had a normal electrocardiogram at the time of examination. Thus, it is suggested that sympathetic denervation is one of the mechanisms causing stunned myocardium.

3-Iodobenzylguanidine↗