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Biomedical subjects

T Matsuo

Publications and source records attributed to T Matsuo.

At least 127 records · Page 7Linked to original sources
PubMed2000

Analysis of hepatic oxidative stress status by electron spin resonance spectroscopy and imaging.

Real-time detection of free radicals generated within the body may contribute to clarify the pathophysiological role of free radicals in disease processes. Of the techniques available for studying the generation of free radicals in biological systems, electron spin resonance (ESR) has emerged as a powerful tool for detection and identification. This article begins with a review of spin trapping detection of oxygen-centered radicals using X-band ESR spectroscopy and then describes the detection of superoxide and hydroxyl radicals by the spin trap 5,5-dimethyl-1-pyrroline-N-oxide and ESR spectroscopy in the perfusate from isolated perfused rat livers subjected to ischemia/reperfusion. This article also reviews the current status of ESR for the in vivo detection of free radicals and in vivo imaging of exogenously administered free radicals. Moreover, we show that in vivo ESR-computed tomography with 3-carbamoyl-2,2,5, 5-tetramethylpyrrolidine-1-oxyl may be useful for noninvasive anatomical imaging and also for imaging of hepatic oxidative stress in vivo.

Animals↗
PubMed2000

Control of CooA activity by the mutation at the C-terminal end of the heme-binding domain.

A constitutively active mutant of a CooA, in which Met131 was replaced by Leu, was isolated by random mutagenesis. Site-directed mutagenesis at position 131 revealed that M131R-CooA was also constitutively active even in the absence of CO and that M131P-, M131D-, and M131E-CooA were constitutively inactive regardless of the presence or absence of CO. While M131L- and M131E-CooA showed almost the same electronic absorption spectra as those of the wild type in the ferric, ferrous, and CO-bound forms, M131D-CooA showed the typical spectrum of a five-coordinate heme protein in the ferric form. The conformational change around the heme induced by CO binding, which triggers the activation of CooA, is thought to be linked to the rearrangement of the conformation around the hinge region between the heme-binding and DNA-binding domains and/or of the relative orientation of the two domains to activate CooA.

Amino Acid Sequence↗
PubMed2000

Construction of a new multi-turn time-of-flight mass spectrometer.

A new type of multi-turn time-of-flight mass spectrometer was constructed, consisting of four cylindrical electric sectors and 28 electric quadrupole lenses, the size of the vacuum chamber being 60 x 70 x 20 cm. It was demonstrated that the mass resolution can be increased according to the number of cycles of the ions through the ion optical system.

Mass Spectrometry↗
PubMed2000

Dissociation study of tellurium cluster ions, Te(n)(+) (n = 25-85) using secondary ion mass spectrometry.

Dissociation pathways of tellurium clusters, Te(n)(+) (n = 25-85), were investigated by secondary ion mass spectrometry. Positively charged ions were generated from a tellurium sheet by bombardment with 10 keV xenon ion beam. Mass analyses of cluster ions were performed using a grand-scale sector mass spectrometer. In the first field-free region, Te(n)(+) (n = 25-80) had a large dissociation probability with five- and six-atom emission and Te(n)(+) (n = 50-85) had a slightly large dissociation probability with 10- and 11-atom emission. Five- and six-atom dissociation in the second field-free region could be also observed. These results were most likely due to the cluster emission processes for Te(n)(+), although sequential atom emission and cluster emission could not be distinguished by this type of experiments.

Spectrometry, Mass, Secondary Ion↗
PubMed2000

Tandem mass spectrometric analysis of (13)C-containing ions from a mixture of homologous peptides differing by one mass unit at a residue.

Tandem mass spectrometry of a mixture of two peptides that differ from each other by a single mass unit due to mutation is presented. The mutant beta-globin of hemoglobin Hoshida is present along with the normal counterpart, and the amino acid substitution of glutamine for glutamic acid is located within tryptic peptide T5 of M(r) 2057. 9. The mass of the mutated peptide is 1 u lower. In the isotopic cluster for the doubly charged ion of the peptide T5, the resolved ion with mass of 1030.0 represents the normal peptide with 93 (12)C atoms and the mutated one with 92 (12)C and one (13)C atoms. Collision-induced dissociation (CID) of this composite ion identified the mutation by presenting a key fragment derived from the (12)C-only mutant peptide, as reported in a previous study. Similarly, when an ion containing multiple (13)C atoms was selected as a precursor for CID, the mutation could be identified, even in large fragments, by a marked change in the shape of the isotopic cluster for the consecutive product ions. This study demonstrates the merit of selecting a resolved ion rather than the whole isotopic cluster as a precursor in the CID measurements of large peptides or proteins for characterizing heterozygous mutations.

Amino Acid Sequence↗
PubMed2000

Polychlorinated dibenzo-p-dioxins and dibenzofurans in sediment, soil, fish, shellfish and crab samples from Tokyo Bay area, Japan.

Concentrations of tetra- to octa-chlorinated dibenzo-p-dioxins and dibenzofurans in samples collected in or near Tokyo Bay, Japan, with a densely inhabited catchment area, were congener-specifically determined and discussed. Analyzed in this study were samples of surface sediment covering the whole bay area, reference soil representing atmospheric impact, and fish, shellfish and crab commonly consumed as food. The range of concentrations were comparable to or higher than those in other parts of Japan. The origins of these compounds in the catchment area of the bay were investigated in terms of homolog and isomeric compositions in the sediment samples. Biota-sediment accumulation factors for benthic species declined as the degree of chlorination increased.

Animals↗
PubMed2000

Skull metastasis of hepatocellular carcinoma associated with acute epidural hematoma: a case report.

BACKGROUND: Although epidural hematoma is well documented in trauma patients, its association with other etiologies, such as neoplasms, is not widely known. Here the authors report a case of acute epidural hematoma that originated from a metastatic hepatocellular carcinoma (HCC) in the skull. CASE DESCRIPTION: A 70-year-old male was admitted to our hospital with left-sided hemiparesis. Preoperative computed tomography (CT) revealed a lenticular high-density area adjacent to the right parietal bone, consistent with an acute epidural hematoma. A subsequent magnetic resonance image (MRI) showed a skull tumor adjacent to the epidural hematoma. Removal of the tumor and evacuation of the hematoma were performed and the pathological diagnosis was metastatic HCC. Postoperatively, the patient gradually recovered but he died of pneumonia 2 months later. CONCLUSION: This report represents an additional example of a rare case of metastatic skull tumor associated with acute epidural hematoma. The authors suggest that metastatic skull tumors may be one of the important differential diagnoses in patients with acute epidural hematoma.

Acute Disease↗
PubMed2000

Absolute number of circulating CD34+ cells is abnormally low in refractory anemias and extremely high in RAEB and RAEB-t; novel pathologic features of myelodysplastic syndromes identified by highly sensitive flow cytometry.

We scored absolute numbers of circulating CD34+ cells by a highly sensitive triple-color flow cytometric analysis using CD45 monoclonal antibody, CD34 monoclonal antibody and propidium iodide. Forty-one patients with MDS (RA: 27, RARS: 1, RAEB: 6, RAEB-t: 3,CMML: 4), 12 patients with aplastic anemia (AA) and 36 age-adjusted normal subjects were studied. RA had significantly decreased numbers of cells expressing CD34 (0.21 +/- 0.29 x 10(6)/l) compared with normal subjects (0.81 +/- 0.36 x 10(6)/l)(P < 0.001). This low number of CD34+ cells in RA resembles the case of AA (0.39 +/- 0.73 x 10(6)/l). In light-scatter analysis, the CD34+ cells of RA patients were distributed mainly in low forward scatter (FSC) (lymphocyte region). In contrast, the CD34+ cell counts were extremely high in patients with RAEB (46.54 +/- 71.37 x 10(6)/l) and RAEB-t (57.00 +/- 52.36 x 10(6)/l) (P < 0.001) and the CD34+ cells were observed in high FSC (blast region).CMML patients showed moderately increased numbers of CD34+ cells (3.69 +/- 4.64 x 10(6)/l). Thus, there was a distinct difference in cell size and number of circulating CD34+ cells between RA and RAEB/RAEB-t. In univariate and multivariate analysis, a high CD34+ cell count (> or = 1.0 x 10(6)/l) was a poor prognostic factor. This method allows one to distinguish RA from other MDS subtypes more reliably than by morphology alone and provides early signs of progression to acute leukemia.

Adult↗
PubMed2000

Identification of ingrowth site of idiopathic subfoveal choroidal neovascularization by indocyanine green angiography.

PURPOSE: This study aimed to determine whether indocyanine green (ICG) angiography is useful to identify the ingrowth site of idiopathic choroidal neovascularization (CNV), which can predict visual outcomes after surgical removal of idiopathic CNV. DESIGN: Consecutive, observational case series. PARTICIPANTS: Twenty-six patients with idiopathic subfoveal CNV, of whom six underwent submacular surgery. INTERVENTION: Indocyanine green videoangiography with a scanning laser ophthalmoscope. MAIN OUTCOME MEASURES: We studied ICG videoangiographic images of choroidal neovascular membranes from the early phase to the late phase with special attention to abnormal findings, which can indicate the ingrowth site of CNV. RESULTS: Early ICG angiography demonstrated distinct neovascular vessels in 24 of the 26 patients (92%). Hypofluorescent rims continuously or intermittently surrounded neovascular membranes on late ICG angiograms in 21 of the 26 patients (81%). In 22 of the 26 patients (85%), ICG angiography demonstrated hypofluorescent areas within the CNV. These hypofluorescent areas frequently became ring shaped in the middle to late phase of the ICG angiography. In 14 of 16 patients (88%) with CNV larger than half a disc area, the filling of neovascular vessels appeared from the inside of the hypofluorescent areas and branched out toward the surrounding hyperfluorescent membrane in the early phase. In all six patients who underwent surgical removal of CNV, ICG videoangiography showed these hypofluorescent areas from which neovascular vessels emanated. Three of the four surgical patients, in whom hypofluorescent areas or central fluorescent areas surrounded by ring-shaped hypofluorescence were extrafoveal or juxtafoveal, had a best postoperative visual acuity of 20/60 or better. In contrast, both surgical patients with subfoveal hypofluorescent areas had a best postoperative visual acuity of 20/70 or worse. CONCLUSIONS: Although further observations are needed, ICG angiography may be a useful adjunct in the identification of the ingrowth site of idiopathic CNV, which can predict visual outcomes after surgery.

Adult↗
PubMed2000

Effect of 22-oxacalcitriol on bone histology of hemodialyzed patients with severe secondary hyperparathyroidism.

To examine the effectiveness of 22-oxacalcitriol (OCT) injection on the improvement of severe osteitis fibrosa, we studied 10 hemodialyzed patients (age, 59 +/- 12 years). The initial OCT dose was 5 microg and was administered three times weekly at the end of each hemodialysis session. OCT doses (1, 3, 5, 10, 15, and 20 microg) were changed in subsequent weeks to maintain serum calcium levels at less than 11.5 mg/dL. Administration of OCT significantly suppressed serum intact parathyroid hormone (PTH) from an initial level of 1,193 +/- 584 to 775 +/- 552 pg/mL in the 24th week (n = 10). OCT increased PTH levels again to 857 +/- 635 pg/mL in the 48th week (n = 7). Among the 10 patients, 5 patients (high responders) showed more than a 50% suppression of serum intact PTH levels at the end of the study. The rest of the patients had hypercalcemia and did not receive increased OCT doses (low responders). At the start of the treatment, the only difference between high and low responders was serum calcium level. Serum calcium levels (adjusted for serum albumin level) increased from 9.7 +/- 0.7 mg/dL (n = 10) at the beginning to 10.5 +/- 0.6 mg/dL (n = 10) in the 24th week and to 11. 1 +/- 0.7 mg/dL (n = 7) in the 48th week. Six patients (1 to 6) agreed to undergo a second bone biopsy in the 24th week of OCT administration. In bone histomorphometric measurements, OCT significantly changed bone marrow fibrosis, mineralization (labeled mineralizing surface and bone formation rate), and osteoid formation (osteoid volume and thickness). In conclusion, intravenous OCT effectively suppressed PTH secretion and improved the bone histological characteristics of severe osteitis fibrosa, especially in patients with initial serum calcium levels less than 10 mg/dL. With concerns about OCT causing adynamic bone, additional bone histological data are needed to ensure the long-term safety of OCT.

Adult↗
PubMed2000

Ex vivo measurement of tissue distribution of a nitroxide radical after intravenous injection and its in vivo imaging using a rapid scan ESR-CT system.

To establish the usefulness of ESR-CT imaging with 3-carbamoyl-2,2,5, 5-tetramethylpyrrolidine-1-oxyl (carbamoyl-PROXYL) in living animals, we investigated the tissue distribution of carbamoyl-PROXYL after i. v. injection. Ten minutes after injection of carbamoyl-PROXYL, its concentrations in the liver, spleen, kidney, and plasma were higher than those in the small intestine and stomach. However, the inter-organ differences in concentrations were not striking. We selected the liver as a representative organ and attempted to measure the concentration of carbamoyl-PROXYL in it after washing out all of the blood by in situ perfusion with saline. The ESR spectrum of the liver homogenate after complete blood washout revealed that the concentration of carbamoyl-PROXYL was significantly reduced. Thus, at this time, carbamoyl-PROXYL was distributed predominantly in the plasma and/or loosely attached to the surfaces of cells. We obtained high-quality ESR-CT images of the murine abdomen at a measurement time of 40 s and found that a high-intensity area of carbamoyl-PROXYL appeared in the liver and kidneys, indicating an abundant blood circulation. Although the organ specificity of carbamoyl-PROXYL was weak, we consider that ESR-CT imaging with carbamoyl-PROXYL will be a powerful new tool for non-invasive anatomic analysis of the liver and the kidneys.

Animals↗
PubMed2000

Basal nitric oxide production is enhanced by hydraulic pressure in cultured human periodontal ligament fibroblasts.

To understand orthodontic tooth movement and determine optimal orthodontic force from a biological viewpoint, nitric oxide production in cultured human periodontal ligament fibroblasts was measured at varying levels of hydraulic pressure. The fibroblasts in a culture flask were exposed to the controlled change in hydraulic pressure, and intracellular nitric oxide levels were measured in real time by a nitric oxide-binding fluorescent dye, diaminofluorescein-2. The fibroblasts produced a significantly larger amount of nitric oxide at the pressure of 75 and 100 mmHg, compared with the pressure of 0, 25, and 50 mmHg (P <.0001, one-way ANOVA, and P <.05, Tukey-Kramer test). Immunohistochemically, the cultured fibroblasts expressed brain nitric oxide synthase. The pressure level to enhance nitric oxide production was comparable to the magnitude of clinically used orthodontic force (80 g/cm(2)). Nitric oxide might be a key regulator in orthodontic tooth movement.

Analysis of Variance↗
PubMed2000

Isolation, characterization and identification of polyhydroxyalkanoate-accumulating bacteria from activated sludge.

Two novel gram-positive bacteria capable of accumulating poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [poly(3HB-co-3HV)] were isolated from an anaerobic-oxic activated sludge system fed with acetate. Strains Lpha5 and Lpha7 are motile cocci, 1-2 microm in diameter, occurring singly or in pairs. These isolates have doubling times ranging from 0.4-1.7 d and can accumulate in high levels of poly(3HB-co-3HV) (up to 44.7% of cell dry weight) when grown on complex media. Furthermore, these two strains exhibited the rapid substrate uptake and accumulation of storage granules as observed in situ. Under aerobic conditions, about 14.4% (cell dry weight) polyhydroxyalkanoate and 82% (carbon dry weight) cellular carbohydrate were produced from acetate and glucose, respectively. Under anaerobic conditions, poly(3HB-co-3HV) and cellular carbohydrate accumulated when glucose but not acetate was fed. The result of analysis of 16S rRNA sequence revealed that both strains belong to the gram-positive high-G + C group, but are significantly different from their closest phylogenetic relatives, Dermatophilus sp. and Terrabacter sp., to warrant classification as a new species.

Journal Article↗
PubMed2000

Colony-forming unit-megakaryocyte (CFR-meg) numbers and serum thrombopoietin concentrations in thrombocytopenic disorders: an inverse correlation in myelodysplastic syndromes.

We studied both serum-free colony-forming unit-megakaryocyte (CFU-meg) numbers and serum thrombopoietin (TPO) levels in 14 patients with aplastic anemia (AA), 37 patients with myelodysplastic syndromes (MDS) and 23 patients with idiopathic thrombocytopenic purpura (ITP) to assess thrombopoiesis in these thrombocytopenic disorders. The mean CFU-meg numbers were lower in AA and MDS patients (10.7 +/- 11.4 and 42.3 +/- 58.5/10(5) BMLD cells) than in healthy controls (103.1 +/- 57.3/10(5) BMLD cells) (P < 0.0001 and P= 0.0053, respectively), although they were distributed variably in MDS. ITP patients showed higher CFU-meg numbers (223.2 +/- 143.5/10(5) BMLD cells) (P= 0.017). The mean TPO concentrations were higher in both AA (986.8 +/- 500.8 pg/ml) and MDS patients (838.2 +/- 639.1 pg/ml) than in healthy controls (80.7 +/- 38.8 pg/ml) (P < 0.0001), although they were distributed from high to low in MDS. ITP patients showed a slight elevation of TPO (123.1 +/- 55.3 pg/ml) P = 0.0106). The TPO levels was inversely correlated to both platelet counts and CFU-meg numbers (correlative coefficient (CC): -0.719 and -0.682, P < 0.0001) in AA, but not in ITP. In MDS, the inverse correlation to TPO was stronger in CFU-meg (CC: -0.678, P < 0.0001) than in platelet counts (CC: -0.538, P = 0.0014), suggesting that CFU-meg plays an important role in regulating TPO production in this heterogenous disorder. CFU-meg and TPO may provide useful information for understanding thrombopoiesis of MDS, especially for application of TPO.

Adolescent↗
PubMed2000

Allogeneic bone marrow transplantation improves the outcome of de novo AML with trilineage dysplasia (AML-TLD).

De novo acute myeloid leukemia (AML) with dysplastic features in erythroblasts, granulocytes and megakaryocytes, similar to those in myelodysplastic syndrome (MDS) has been described as AML with trilineage dysplasia (AML-TLD) since 1987. Several reports have suggested that AML-TLD is a subtype of de novo AML in adults and has a poor clinical outcome when treated by conventional chemotherapy. It is not certain whether allogeneic bone marrow transplantation (BMT) brings a favorable outcome for AML-TLD. To evaluate the therapeutic efficacy of allogeneic BMT for AML-TLD, we investigated the clinical data and outcomes of conventional chemotherapy and allogeneic BMT for 118 patients with de novo AML. These patients were registered consecutively for the Japan Adult Leukemia Study Group (JALSG) protocols at our institutes. We treated 28 AML-TLD patients and 90 AML-nonTLD patients with conventional chemotherapeutic protocols. AML-TLD patients did not have a significantly different complete remission (CR) rate (75.0% and 88.4% P = 0.1234), but had a significantly higher relapse rate than AML-nonTLD patients (94.1% and 49.3%, P= 0.0007). The outcome of chemotherapy for AML-TLD was significantly worse than that for AML-nonTLD. The overall survival (OS) and leukemia-free survival (LFS) at 6 years were 9.4% and 0% in AML-TLD group, and 51.9% (P= 0.0017) and 46.3% (P< 0.0001) in AML-nonTLD group, respectively. Meanwhile, among the patients who underwent allogeneic BMT, five of eight AML-TLD patients and eight of 14 AML-nonTLD patients were alive, and three and five patients survived more than 3 years, respectively. These results suggest that allogeneic BMT can improve the outcome for AML-TLD, which is poor when conventional chemotherapy is given alone. Allogeneic BMT before relapse may be the best therapeutic strategy for AML-TLD patients under 50 years of age if a donor is available.

Adolescent↗
PubMed2000

Virus-associated haemophagocytic syndrome responsive to steroid pulse therapy and double filtration plasmapheresis.

We present an adult patient with haemophagocytic syndrome (HPS) successfully treated with a combination of steroid pulse therapy and double filtration plasmapheresis (DFPP). A 58-year-old male was admitted with high fever, severe renal dysfunction, liver dysfunction and an increased level of lactate dehydrogenase. A serological test for Epstein-Barr (EB) virus showed an elevation of EBNA-IgM antibody titre. There were increased haemophagocytic histiocytes in the bone marrow in addition to thrombocytopenia and disseminated intravascular coagulation (DIC) accompanied by organ dysfunction. EB virus associated haemophagocytic syndrome was diagnosed. On admission, interferon (IFN)-gamma, interleukin (IL)-6, IL-8, granulocyte colony-stimulating factor (G-CSF) and macrophage (M)-CSF were elevated, and were promptly normalized after steroid pulse therapy was initiated. G-CSF and M-CSF gradually decreased after DFPPs was started. To control hypercytokinaemia until treatment for the underlying disease is initiated, steroid pulse therapy and double filtration plasmapheresis are useful.

Antibodies, Viral↗
PubMed2000

Spontaneous regression of hepatocellular carcinoma and review of literature.

A 68-year-old man presented with multiple hepatocellular carcinoma, which was considered to be unresectable at the first admission in January 1994. Pathological diagnosis was made by biopsy of the one lesion among them. From January 1994 to December 1997, 10 transarterial chemoembolizations and six percutaneous ethanol injection therapies were performed on the tumours in the cirrhotic liver. In February 1998 the tumour situated in the right lobe began to increase in size. The maximum tumour diameter was 6.3 cm measured by computed tomography (CT). In the beginning of May 1998 moderate ascites was present and mild hepatic encephalopathy was noticed. The patient was in the terminal stage of hepatocellular carcinoma and no further treatment was possible at that time. However, serum alpha-fetoprotein and protein induced by vitamin K absence or antagonist II dramatically decreased in June 1998. The CT scan also showed that the tumour had completely regressed without specific treatment. In February 1999 a new biopsy-proven hepatocellular carcinoma, 2 cm in diameter, developed in the lateral segment of the liver. It was well treated by percutaneous ethanol injection therapy. The patient was alive in good condition without any symptoms or tumour recurrence in June 1999. It was concluded that a rare case of spontaneous regression of hepatocellular carcinoma had occurred.

Aged↗