Search PubMed⌕ Search

Biomedical subjects

T Hidaka

Publications and source records attributed to T Hidaka.

At least 37 records · Page 2Linked to original sources

[Estimation of daily dietary intake of aluminum].

The daily dietary intake of aluminum was estimated through a total diet study from 1996 to 1998. In ten institutes, total diet study samples were prepared and their aluminum concentration was determined. The average daily intake of aluminum was 3.5 mg and the range was 1.8-8.4 mg. The validity of the analytical result was supported by analyses of certified reference materials.

Aluminum↗

[Case report of a malignant schwannoma in the neck with rare pathological findings].

In this report, we describe a rare case of a malignant transformation in an ancient schwannoma arising in the right side of the neck of a 51-year-old man. The patient was referred to our hospital because of a mass that had been present for three years. The mass, measuring about 4 x 2 cm, was elastic and hard, relatively well demarcated, and movable upon palpation. Aspiration cytology was performed, but the diagnosis was unclear histologically. The patient was placed under general anesthesia and the tumor was totally excised. The tumor, which was easily excised, was connected to the sympathetic nerve at both poles. The histological diagnosis was a malignant transformation in an ancient schwannoma. The patient showed no clinical manifestations suggesting neurofibromatosis. Three months after the operation, a recurrent tumor, which was not resectable, was discovered extending deep into the skull base. The patient underwent two operations and two courses of radiation therapy, but the tumor metastasized to the lung and liver. He died of pulmonary failure eleven months after the initial treatment.

Head and Neck Neoplasms↗

Lipid microspheres incorporated by U937 cells via their specific receptors.

Lipid microspheres (LM), currently in clinical use as drug carriers, mainly consist of soybean oil as a core and lecithin as a surfactant. The purpose of our study wass to determine whether or not LM incorporation is receptor-mediated. U937 cells resuspended in a serum-free medium abundantly took up unmodulated LM. A binding study showed that U937 cells had a single binding site for LM (410 sites/cell at 24 degrees C; 100 sites/cell at 4 degrees C). Inhibition assays revealed that lecithin liposome, lysophosphatidylcholines, activated alpha2-macroglobulin, and HDL did not affect the binding of LM to U937 cells. VLDL strongly, and LDL and AcLDL moderately, inhibited the binding of LM to U937 cells. Ligand blotting analysis revealed that unmodulated LM in an apoprotein-free buffer directly bound to a 40 kDa protein in the cell membrane fraction. These results suggest that LM that is not modulated by any protein is incorporated by specific cells via receptor-mediated processes.

Binding Sites↗

Advanced treatment of sewage by pre-coagulation and biofilm process.

Treatment performance and operational parameters of a pre-coagulation and biofilm process were experimentally discussed with the pilot-scale plant treating actual municipal sewage. Perfect nitrification was accomplished within total hydraulic retention time (HRT) of 4 h at 20% volumetric added ratio of attached-growth media of biofilm in the aerobic tanks under temperature conditions as low as 17 degrees C. Treatment efficiencies in organic matter, T-N and T-P were high and stable with the total HRT of 8 h in the biological reactor. Concentrations of T-N and T-P in effluent were kept about 2 mgN/L and under 1 mgP/L, respectively. Attached growth bacterial mass and the potential activity of nitrification and denitrification in each tank in cold season were high enough to accomplish excellent treatment performance. Then the process was proved to be applicable to municipal sewage treatment for removal of nitrogen and phosphorus as well as organic matter.

Biofilms↗

[Dissecting aneurysm of the anterior cerebral artery with persistent pearl & string sign on cerebral angiograms over a period of eight years].

We present a rare case of a dissecting aneurysm of the left anterior cerebral artery (ACA) with persistent pearl & string sign on cerebral angiograms over a period of 8 years. A 43-year-old woman with disturbance of consciousness and right sided hemiparesis was conservatively treated. Computed tomographic (CT) scan revealed a low-density area in the left frontal lobe. Initial angiography, which was performed at 6 months after the onset, showed a pearl & string sign at the A2 portion of the left ACA. After 8 years, repeat angiography again showed persistent pearl & string sign at the same portion of the left ACA. We discussed the changes in findings usually obtained in cerebral angiography concerning dissecting aneurysms in ACA.

Adult↗

[Primary splenic CD8-positive diffuse large B-cell lymphoma].

A 71-year-old woman was admitted for further examination of an increased serum LDH level. Abdominal ultrasonography and CT scan showed a large tumor in her spleen. Because malignant lymphoma was suspected, the spleen was removed for diagnosis and treatment planning. The histopathological and immunohistochemical features of the tumor indicated diffuse large B-cell lymphoma (DLBL). The flow-cytometric immunophenotype of the lymphoma cells was CD2-, CD3-, CD4-, CD5-, CD8+, CD10+, CD19+, CD20+, CD23-, kappa+, lambda-, CD25+, and CD56-. From these findings, the patient was diagnosed as having CD8+ DLBL. To our knowledge, this is the first reported case of primary splenic CD8-positive DLBL.

Aged↗

Identification and expression of the gene encoding phosphonopyruvate decarboxylase of Streptomyces hygroscopicus.

The first step of C-P compound biosynthesis is a C-P bond formation reaction catalyzed by phosphoenolpyruvate phosphomutase, but this reaction favors the cleavage of the C-P bond. This C-P bond forming reaction is driven by the following reaction catalyzed by phosphonopyruvate (PnPy) decarboxylase. We have cloned and sequenced the gene (bcpC) encoding PnPy decarboxylase, a key enzyme of C-P compound biosynthesis, from the bialaphos (BA) producing microorganism Streptomyces hygroscopicus by complementation methods using Streptomyces wedmorensis NP-7, which is a mutant of a fosfomycin producing strain deficient in this step. The location of this gene in the BA biosynthetic gene cluster was determined by using the expression system in Streptomyces lividans. DNA sequencing of this gene revealed a 1203-bp open reading frame encoding a polypeptide of 401 amino acids.

Bacterial Proteins↗

Adsorption of anti-annexin V using dextran sulfate bound cellulose beads.

Anti-annexin V (Anx V) antibodies are detected in SLE patients and patients with habitual fetal loss or preeclampsia. Several case reports have indicated that recurrent abortion based on antiphospholipid syndrome (APS) could be successfully treated with immunoadsorption by using dextran sulfate (DS) columns. The purpose of this study is to clarify whether or not anti-Anx V is also adsorbed by DS-bound cellulose beads. Sera from anti-Anx V-positive patients were mixed with DS-bound cellulose beads in vitro, and the titers of anti-Anx V were measured both before and after incubation. The anti-Anx V titers significantly decreased after incubation. The Anx V also bound to bovine serum albumin-conjugated DS immobilized on microtiter plates. The results of the present study lend support to the basic rationale for immunoadsorption therapy using DS columns in the treatment of habitual abortion closely associated with anti-Anx V antibodies.

Adolescent↗

Neoadjuvant intraarterial infusion chemotherapy in patients with stage IB2-IIIB cervical cancer.

OBJECTIVES: The purpose of this study was determine the effect of neoadjuvant intraarterial chemotherapy (NAIC) on the prognosis of patients with locally advanced cervical cancer. METHODS: From January 1992 to December 1997, 26 previously untreated patients with stage IB2-IIIB cervical cancer were enrolled in the study. NAIC was administered for more than two courses every 3 weeks using a combination of 17.5 mg/m(2) bleomycin, 7 mg/m(2) mitomycin-C, and 75 mg/m(2) cisplatin via the bilateral internal iliac artery. Pathologic findings were evaluated with histologic examinations of surgical specimens. A nonrandomized control group of 120 patients who underwent conventional treatment between 1980 and 1991 was used for comparison. RESULTS: Nineteen (73.1%) of the 26 patients responded to initial chemotherapy, permitting a radical hysterectomy with pelvic lymphadenectomy in 14 patients. The remaining 5 patients received radiotherapy. One of 7 nonresponders was able to undergo radical surgery. Pathologic complete responses were found in 4 of the 15 patients who underwent radical surgery. The incidence of lymph node metastasis, parametrial infiltration, and vascular space involvement in the 15 patients who received NAIC followed by radical surgery was significantly lower than that in the control group (13.3, 6.7, and 13.3% vs 54.2, 43.8, and 60.4%). The overall 5-year estimated survival rate was significantly higher for all 26 patients who received NAIC (80.0%) than for the control group (59.6%). In stage II and III, the 5-year survival rate for patients who received NAIC was significantly higher than that in the control group (83.3 and 77.8% vs 68.1 and 49.8%). CONCLUSIONS: These preliminary results suggest that NAIC is able to eliminate effectively the pathologic risk factors in the pelvic cavity, to improve the operability in patients with stage IIIB cervical cancer, considered inoperable, and to improve the prognosis of patients with locally advanced cervical cancer.

Adenocarcinoma↗

Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: a case report with an immunohistochemical study.

A rare example of malignant transformation in an ancient schwannoma arising in the right side of the neck of a 51-year-old man without any clinical manifestations suggesting neurofibromatosis is described. The tumor, approximately 4 cm at its largest dimension, was well circumscribed and had a direct connection with the sympathetic nerve. Microscopically, the central portion of the tumor showed features of ancient schwannoma characterized by extensive hyalinization with cystic degeneration, scattered spindle cells with hyperchromatic and tapered nuclei, and some symplastic changes. However, predominantly in the outer portion, a proliferation of spindle-shaped cells with enlarged nuclei was present. The nuclei of these cells showed irregular contours, coarse granular chromatin texture, and conspicuous nucleoli. Mitotic figures and small necrotic foci with scattered apoptotic bodies were also seen. Immunohistochemically, S-100 protein was almost negative in areas consisting of overtly atypical cells where the mitotic index evaluated with MIB-1 antibody was 30.5%. In contrast, S-100-positive bland spindle cells were scattered in an extensively hyalinized area with a labeling index less than 3%. P53 protein was strongly positive in atypical spindle cells. Although it is a very uncommon event, definite nuclear atypia, frequent mitotic figures, and the existence of small necrotic foci should be recognized as indicating a diagnosis of malignant degeneration of benign schwannoma. Immunohistochemistry would be useful as an ancillary technique in such a setting.

Biomarkers, Tumor↗

Continence and some properties of the urethral striated muscle of male greyhounds.

OBJECTIVE: To determine the properties of the striated muscle of the greyhound (dog) urethra and to consider its role in maintaining continence. Materials and methods The thickness of the muscle layers and the muscle types were determined by examining sections stained with haematoxylin and eosin or Masson's trichrome. These factors were correlated with the mechanical and electrical responses of muscle strips to nerve stimulation, and compared with muscle from other breeds of dog and other parts of the animal. RESULTS: The striated muscle formed approximately 70% of the membranous urethra and was predominantly (68%) type IIa muscle (i.e. fast but fatigue-resistant). The mean resting membrane potential was -74 mV; nerve stimulation produced an action potential with a mean amplitude of 97 mV and contraction lasting about 200 ms. All responses were abolished by D-tubocurarine. The contractions were well maintained with continuous or intermittent stimulation. The properties were intermediate between those of the anconeus (slow) and the extensor carpi radialis (fast) muscles. CONCLUSIONS: The distribution, fibre type and contractile characteristics would enable the striated urethral muscle to maintain tension for continence at rest and provide additional continence during sprints.

Animals↗

Identification of enzymes responsible for rifalazil metabolism in human liver microsomes.

1. The major metabolites of rifalazil in human are 25-deacetyl-rifalazil and 32-hydroxy-rifalazil. Biotransformation to these metabolites in pooled human liver microsomes, cytosol and supernatant 9000g (S9) fractions was studied, and the enzymes responsible for rifalazil metabolism were identified using inhibitors of esterases and cytochromes P450 (CYP). 2. The 25-deacetylation and 32-hydroxylation of rifalazil occurred in incubations with microsomes or S9 but not with cytosol, indicating that both the enzymes responsible for rifalazil metabolism were microsomal. Km and Vmax of the rifalazil-25-deacetylation in microsomes were 6.5 microM and 11.9 pmol/min/mg with NADPH, and 2.6 microM and 6.0 pmol/min/mg without NADPH, indicating that, although rifalazil-25-deacetylation did not require NADPH, NADPH activated it. Rifalazil-32-hydroxylation was NADPH dependent, and its Km and Vmax were 3.3 microM and 11.0 pmol/min/mg respectively. 3. Rifalazil-25-deacetylation in microsomes was completely inhibited by diisopropyl fluorophosphate, diethyl p-nitrophenyl phosphate and eserine, but not by p-chloromercuribenzoate or 5,5'-dithio-bis(2-nitrobenzoic acid), indicating that the enzyme responsible for the rifalazil-25-deacetylation is a B-esterase. 4. Rifalazil-32-hydroxylation in microsomes was completely inhibited by CYP3A4-specific inhibitors (fluconazole, ketoconazole, miconazole, troleandomycin) and drugs metabolized by CYP3A4 such as cyclosporin A and clarithromycin, indicating that the enzyme responsible for the rifalazil-32-hydroxylation is CYP3A4.

Acetylation↗

Detection of apoptosis and expression of apoptosis-associated proteins as early predictors of prognosis after irradiation therapy in stage IIIb uterine cervical cancer.

We investigated the proportion of apoptotic cells and the expression of apoptosis-associated proteins after the delivery of the first week of irradiation for stage IIIb uterine cervical cancer. Thirty patients with stage IIIb squamous cell carcinoma of the uterine cervix who received only irradiation therapy were registered in this study. Specimens were obtained before irradiation therapy and at the end of the first week of irradiation. The apoptotic index (AI) of each tissue specimen was calculated by counting the apoptotic cells and expressed as a percentage. Immunohistochemical evaluation for apoptosis-related proteins, p53, Bcl-2, Bax, caspase-1 and caspase-3 was also performed. The AI was 0.8+/-0.9% (mean+/-SD) before irradiation and 1.7+/-1.3% at the end of the first week of irradiation. We observed that the patients who survived more than 5 years had AI levels of 2.1+/-1.3% at the end of their first week of therapy. This rate was significantly higher than the rate of 1.1+/-0.8% (P=0.02) of the patients who died within 5 years. When the cut-off value of the AI was set at 1.7%, the sensitivity, specificity, positive predictive value, and negative predictive value for the prediction of patients' prognosis after irradiation therapy were 73.4%, 72.4%, 82.4%, and 61.5%, respectively. In 17 of the AI-positive cases, expressions of Bax (P=0.006), caspase-1 (P=0.045), and caspase-3 (P=0.013) at the end of the first week were significantly higher than before irradiation. The proportion of apoptotic cells and the expression of apoptosis-associated proteins, Bax, caspase-1, and caspase-3, at the end of the first week of irradiation could be useful predictors of the prognosis in stage IIIb squamous cell carcinoma of the uterine cervix treated by irradiation therapy.

Aged↗

Acoustical design of the Tokyo Opera City (TOC) concert hall, Japan

The Tokyo Opera City concert hall seats 1632, volume 15 300 m3, and reverberation time, with audience and orchestra, 1.95 s. As part of the design process, measurements on CAD computer and 1:10 wooden models of the hall and full-sized materials samples were conducted over a 5-yr. period. The hall in plan is rectangular. The ceiling is a distorted pyramid, with its peak 28 m above the main floor and nearer the stage than the rear of the hall. This unique shape was analyzed on the models so that all interior surfaces combine to distribute sources on the stage uniformly over the seating areas and to yield optimum values for reverberation time (RT), early decay time (EDT), interaural cross-correlation coefficient (IACCE3), bass ratio (BR), initial-time-delay gap (ITDG), strength (G), and sound diffusion index (SDI) [for definitions see L. Beranek, Concert and Opera Halls: How They Sound (Acoustical Society of America, Woodbury, NY, 1996)]. On the long ceiling facing the stage, Schroeder QRD diffusers provide diffusion, eliminate a possible echo, and strengthen lateral reflections. Performers and critics judge the acoustics excellent.

Journal Article↗

Objective and subjective evaluations of twenty-three opera houses in Europe, Japan, and the Americas

The room acoustical parameters, reverberation time RT, early decay time EDT, clarity factor C80, bass ratio BR, strength G, interaural cross-correlation coefficient IACC, and initial-time-delay gap ITDG [definitions in Hidaka et al., J. Acoust. Soc. Am. 107, 340-354 (2000) and Beranek, Concert and Opera Halls: How They Sound (Acoustical Society of America, New York, 1996)], were measured in 23 major opera houses under unoccupied conditions in 11 countries: Argentina, Austria, Czech, France, England, Germany, Hungary, Italy, Japan, The Netherlands, and the USA. Questionnaires containing rating scales on the acoustical quality of 24 opera houses were mailed to 67 conductors, 22 of whom responded. The objective measurements were analyzed for reliability and orthogonality, and were related to the subjective responses. Presented are (a) the rankings of 21 opera houses each rated by at least 6 conductors for acoustical quality as heard by them both in the audience areas and in the pit; (b) relations between objective room acoustical parameters and subjective ratings; (c) findings of the most important of the parameters for determining acoustical quality: RT (or EDT), G(M), ITDG, [1 - IACC(E3)], texture (appearance of reflectrograms in the first 80-100 ms after arrival of the direct sound), a lower limiting value for BR, and major concern for diffusion and avoidance of destructive characteristics (noise, vibration, echoes, focusing, etc.); (d) the differences between average audience levels with and without enclosed stage sets; and (e) the differences between average levels in audience areas for sounds from the stage and from the pit.

Journal Article↗

Acoustical design of the opera house of the New National Theatre, Tokyo, Japan

Architect Takahiko Yanagisawa's preface explains his approach to the design. The NNT opera house seats 1810, its volume is 14500 m3, and its reverberation time, with audience, is 1.5 s (proscenium curtain open). Measurements on CAD computer and 1:10 wooden models and full-sized materials samples were conducted over a 7-yr. period. The main floor is almost rectangular, the three balconies have modest fan shape in plan, although the balcony facia at each level create a rectangular shape. The unique design has a large curved reflector in front of and above the proscenium and six curved reflecting surfaces at the front ends of the three side balconies to form, in combination, an "acoustic trumpet." These surfaces, along with the balcony faces and the shaped ceiling, distribute the singers' voices uniformly over the seating areas from a large portion of the large stage at sound levels that easily override the orchestra in the pit.

Journal Article↗

Studies on antihypertensive agents with antithrombotic activity. 2. Syntheses and pharmacological evaluation of pyrrolo[2,3-c]azepine derivatives.

As an extension of our previous investigation, a series of 7-aminoalkylpyrrolo[2,3-c]azepine derivatives was synthesized and evaluated as alpha1-adrenergic- and serotonin 2 (5-HT2)-receptor antagonists, with the aim of finding a novel potent antihypertensive agent with both activities. Among the compounds obtained in this study, (E)-1-ethyl-7-[3-[4-(4-fluorophenyl)piperazin-1-yl]propyl]-4-hy droxyimino-1,4,5,6,7,8-hexahydropyrrolo[2,3-c]azepin-8-on e (16d) displayed potent alpha1-adrenoceptor blocking activity (pA2=7.83+/-0.20) and 5-HT2-receptor blocking activity (pA2=9.47+/-0.17) in isolated guinea pig arteries. At 3 mg/kg oral administration, compound 16d exhibited antihypertensive activity more potent than that of doxazosin in deoxycorticosterone acetate (DOCA)-salt hypertensive dogs. Furthermore, this compound reduced the rate of mouse acute pulmonary thromboembolytic death induced by collagen and serotonin at oral doses of 0.3 mg/kg or more, and its effect lasted for at least 6 h at 3 mg/kg.

Adrenergic alpha-1 Receptor Antagonists↗