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Biomedical subjects

H Shibuya

Publications and source records attributed to H Shibuya.

At least 181 records · Page 10Linked to original sources
PubMed1997

The use of three-phase scintigraphy for diagnosing hemangiomas of the extremities. A clinical evaluation.

Five hemangiomas were found in four patients and were assessed by three-phase blood perfusion and blood-pool scintigraphy to determine the usefulness of this method for the imaging characteristics of different types of hemangiomas of the extremities. After injecting Tc-99m RBC or Tc-99m DTPA HSA, dynamic perfusion and early and delayed pool images were obtained and analyzed. The perfusion images of one cavernous hemangioma and two venous hemangiomas showed normal activity, but blood-pool imaging showed increased activity, whereas on perfusion imaging and early blood-pool imaging, another cavernous hemangioma showed a partial increase in activity in its periphery and on delayed blood-pool imaging, diffuse increase in activity. Further, the remaining hemangioma, a mixed-type hemangioma, showed, diffuse increase in activity on both perfusion and blood-pool imaging. Thus, three-phase scintigraphy was found useful in evaluating and achieving a diagnosis of a hemangioma of the extremities.

Adolescent↗
PubMed1997

An association study between a transcriptional polymorphism in the serotonin transporter gene and panic disorder in a Japanese population.

A polymorphism in the 5' region of the serotonin transporter gene modulates its transcription efficiency. Its short allele has been reported to be associated with neurotic traits. The serotonin transporter is the action site of selective serotonin re-uptake inhibitors, widely used in the treatment of panic disorder. We examined an association between the polymorphism and panic disorder in a case-control study consisting of 66 Japanese patients and 150 controls. The short allele was significantly more frequent in the Japanese than in Caucasians. The patients and the controls had similar allele frequencies, indicating no association between the polymorphism and panic disorder in most Japanese patients.

Adult↗
PubMed1997

Immunohistochemical localization of endothelin-1, endothelin-3 and endothelin receptors in human pheochromocytoma and paraganglioma.

Endothelin (ET) and its receptor system have been shown to exert various biological effects on different types of cells in addition to their well-known vasoconstrictor activity. Recently ET-1, ET-3 and the ETB receptor have been shown to play an important role in the development of neural crest-derived cells and, in this context, pheochromocytomas have been reported to harbor ET-1. Endothelin-3 or ET receptor subtypes, however, have not been examined in pheochromocytoma and paraganglioma so far. In the present study the immunohistochemical localization of ET-1/big ET-1, ET-3/big ET-3 and the ETA and ETB receptors were investigated to clarify the biological characteristics of these two tumors using 32 pheochromocytomas and 11 extra-adrenal paragangliomas. Endothelin-1/big ET-1 was detected in 19 pheochromocytomas (59%) and eight paragangliomas (72%), while ET-3/big ET-3 was detected in 10 pheochromocytomas (31%) and three paragangliomas (27%). The ETA receptor was found in 21 pheochromocytomas (66%) and in eight paragangliomas (73%), while the ETB receptor was found in 25 pheochromocytomas (78%) and in eight paragangliomas (73%). Normal adrenomedullary cells lacked each antigen examined. Endothelin-immunoreactive tumor cells were distributed focally or in a manner scattered, while receptor-immunostained tumor cells were distributed with a focal pattern for the ETA receptor and with a focal or diffuse pattern for the ETB receptor. Endothelin and its receptor coexisted in the same tumor in 21 of 28 ET-positive pheochromocytomas and in eight of 10 ET-positive paragangliomas. In addition, seven pheochromocytomas and two paragangliomas revealed positivity of the receptor(s) irrespective of the absence of ET-immunoreactivity. In conclusion, ET and its receptor are frequently and concomitantly expressed in the pheochromocytoma and paraganglioma. From the highly frequent expression of this system or the receptor(s), ET-receptor-mediated signal transduction of these tumors concerning growth and/or cell survival is expected, although definite biological significance of this ligand-receptor system in these tumors awaits further investigation.

Adrenal Gland Neoplasms↗
PubMed1997

Staging of esophageal carcinoma in vitro with 4.7-T MR imaging.

PURPOSE: To determine the accuracy of 4.7-T magnetic resonance (MR) imaging for evaluating the mural invasion of esophageal carcinoma. MATERIALS AND METHODS: Sixty-seven esophageal specimens containing 70 squamous cell carcinomas were studied with a 4.7-T MR system with a 4-cm-diameter surface coil. Spin-echo MR images were obtained with a field of view of 4-6 cm, matrix size of 256 x 256, and section thickness of 3 mm, which resulted in a voxel size of 0.08-0.16 mm3. MR findings were compared with histopathologic findings, which served as the standard of reference. Tumor invasion on MR images was determined by consensus of two radiologists. RESULTS: T2-weighted images depicted six to eight layers of the normal esophageal wall; these correlated well with layers identified with histologic examination. In 66 (94%) of 70 cases of esophageal carcinoma, the depth of mural invasion visualized with MR imaging correlated well with that determined with histopathologic examination. The stage determined with MR imaging, however, was higher in two (3%) and lower in two (3%) cases than that determined with histopathologic examination. MR imaging enabled visualization of the gross features of tumor growth pattern, tumor ulceration, and adjacent lymph node involvement. CONCLUSION: MR imaging in vitro allows accurate assessment of the mural invasion of esophageal carcinoma and thus potentially enables preoperative histopathologic staging.

Carcinoma, Squamous Cell↗
PubMed1997

Retrohepatic cavoatrial shunt with a ringed polytetrafluoroethylene graft for the Budd-Chiari syndrome. A case report.

This report describes a patient with Budd-Chiari syndrome who was operated on successfully by means of shunt formation with polytetrafluoroethylene graft between the inferior vena cava (IVC) and right atrium. The patient is a sixty-two-year-old woman suffering from persistent edema of the lower limbs for four years. The examination disclosed complete obstruction of the IVC at the level of the diaphragm with a patent right inferior hepatic vein. Following the operation, edema of the limbs disappeared, hypersplenism improved, and the serum ammonium concentration decreased to the normal range. In conclusion, a retrohepatic cavoatrial shunt is feasible and useful in treating a patient with the Budd-Chiari syndrome who has patent major hepatic veins.

Blood Vessel Prosthesis↗
PubMed1997

Indonesian medicinal plants. XXI. Inhibitors of Na+/H+ exchanger from the bark of Erythrina variegata and the roots of Maclura cochinchinensis.

Through bioassay-guided separation of the methanol extracts of Indonesian medicinal plants, three inhibitors of the Na+/H+ exchange system, erythrinin B (2), euchrenone b10 (3), and 1,3,5-trihydroxy-4-(3-methylbut-2-enyl)xanthen-9-one (4), were isolated from the bark of Erythrina variegata (Fabaceae) (for 2) and the roots of Maclura cochinchinensis (Moraceae) (for 2, 3, 4). Compounds 2, 3, and 4 significantly inhibited the Na+/H+ exchange system of arterial smooth muscle cells, with minimum inhibitory concentrations of 1.25, 1.25, and 10 micrograms/ml, respectively. Three new prenylated xanthones named isocudraniaxanthones B (5) and A (7) and isoalvaxanthone (9) were also isolated from M. cochinchinensis and the chemical structures were elucidated on the bases of their chemical and physicochemical properties.

Animals↗
PubMed1997

Indonesian medicinal plants. XIX. 1) Chemical structures of four additional resin-glycosides, mammosides A, B, H1, and H2, from the tuber of Merremia mammosa (Convolvulaceae).

Four new resin-glycosides, named mammosides A (10), B (11), H1 (12), and H2 (13), were isolated from the tuber of Merremia mammosa (Convolvulaceae), a Jamu raw material. Their chemical structures have been elucidated on the bases of chemical and physicochemical evidence, including synthesis of a glycosidic acid designated as mammoside I.

Carbohydrate Sequence↗
PubMed1997

Purification, characterization, and cDNA cloning of a novel alpha-galactosidase from Mortierella vinacea.

A novel alpha-galactosidase, designated alpha-galactosidase II, was isolated from the culture filtrate of Mortierella vinacea. The molecular size of the purified enzyme estimated by gel filtration was 60 kDa, which agreed with that, 51-62 kDa, estimated by SDS-PAGE. The enzyme was thermolabile at neutral pH, but the addition of BSA to the enzyme solution at the concentration of 0.01% increased its stability considerably. The enzyme appears to be novel because it showed a distinct substrate specificity from other microbial alpha-galactosidases on galactomanno-oligosaccharides, prepared from galactomannan, that is, the enzyme liberated not only side-chain alpha-galactosyl residue from 6(3)-mono-alpha-D-galactopyranosyl-beta-1,4-D-mannotetraose but also terminal alpha-galactosyl residue from 6(3)-mono-alpha-D-galactopyranosyl-beta-1,4-D-mannotriose. In addition, the enzyme acted on galactomannans effectively. alpha-Galactosidase II cDNA was cloned and its nucleotides sequenced. The deduced amino acid sequence showed that the mature enzyme consisted of 376 amino acid residues with a molecular mass of 41,334 Da. The derived amino acid sequence of the enzyme showed 31-49% sequence similarity with those of alpha-galactosidases from other origins.

Amino Acid Sequence↗
PubMed1997

Quantitative and compositional changes in high density lipoprotein subclasses in patients with various genotypes of cholesteryl ester transfer protein deficiency.

High density lipoprotein (HDL) with and without apolipoprotein (apo) E was quantified and characterized in subjects with three genotypes of cholesteryl ester transfer protein (CETP) deficiency: the nonsense mutation in intron 14 (10 homozygotes and 5 heterozygotes); the missense mutation in the exon 15 (3 homozygotes and 9 heterozygotes); and the Int14A/D442G in 6 compound heterozygotes. ApoE-poor and apoE-rich HDL-cholesterol levels were elevated significantly in all genotypic groups with the decrease in CETP activity, indicating that both types of HDL-cholesterol can be a substrate for CETP. However, an unchanged or only slightly increased serum apoA-II level in each genotype indicated that the HDL particles with apoA-II are relatively resistant to CETP-mediated lipid transfer. Serum apoE-rich HDL level was considerably higher in the Int14A homozygotes than in the compound heterozygotes, in spite of similar apoE-poor HDL-cholesterol levels, which may indicate that apoE-rich HDL is a better substrate for CETP than apoE-poor HDL. Although the apoE-rich and apoE-poor HDL subclasses were similar in the accumulation of cholesteryl ester and depletion of triglyceride, the accumulation of free cholesterol was unique to apoE-rich HDL, indicating inhibited cholesterol esterification on this lipoprotein. Clinical laboratories should be aware of the discrepancy in HDL-cholesterol measurements that comes from the different recoveries of apoE-rich HDL using commercial reagents. In conclusion, CETP deficiency causes considerable quantitative and compositional changes in HDL subclasses, reflecting a significant physiological role for CETP in HDL metabolism.

Adult↗
PubMed1997

Immunochemical localization of the Batten disease (CLN3) protein in retina.

PURPOSE: Batten disease, also known as juvenile ceroid-lipofuscinosis and CLN3, is an autosomal recessively inherited disorder that results in blindness due to retinal degeneration. The CLN3 gene has been identified, but the function of the protein that this gene encodes is unknown. Experiments were conducted to determine where the CLN3 protein is localized in the mouse retina. Localization should provide a clue in evaluating potential functions of this protein. METHODS: Using oligonucleotide primers based on the reported human CLN3 cDNA sequence, the mouse cDNA nucleotide sequence was determined from products of the reverse transcriptase-polymerase chain reaction and 3' rapid amplification of cDNA ends. A synthetic 20-amino-acid peptide corresponding to an internal hydrophilic region of the predicted amino acid sequence of the mouse CLN3 protein was used to immunize rabbits. The resulting antiserum was used in immunoblot analysis of mouse retina homogenates and in electron microscopic immunocytochemical labeling of mouse retina sections. RESULTS: The peptide antibody labeled a single protein band of approximately 50 kDa on immunoblots of mouse retina homogenates. No labeling was detected with homogenates from human retinas. The antibody specifically labeled mitochondria of Müller cells and inner retinal neurons. Little labeling was observed in mitochondria of the photoreceptor cells. Mitochondria of other cell types, including the retinal pigment epithelium and choroidal cells, were not labeled. CONCLUSIONS: The retinal CLN3 protein appears to be localized almost exclusively in the mitochondria, but was detected only in certain cell types. Batten disease is characterized by massive lysosomal accumulations of a small inner mitochondrial membrane protein (subunit c of ATP synthase). The mitochondrial localization of the CLN3 protein suggests that it may play a role in the normal processing of subunit c.

Amino Acid Sequence↗
PubMed1997

[Diffuse large B-cell lymphoma mainly involving the heart and showing t(8;14) (q24;q32) with c-myc rearrangement].

A 77-year-old man was admitted because of massive pericardial effusion and cardiac tumor. Cytological examination of the effusion and histological examination of a subcutaneous tumor in the chest wall revealed diffuse large B cell lymphoma. The immunophenotype of tumor cells was CD5+ CD20+ CD22+ CD38+ HLA-DR+ CD19-. Chromosome analysis revealed complex abnormal karyotypes containing t(8;14) (q24;q32). C-myc gene rearrangement was shown by Southern blotting. Chemotherapy with pirarubicin, cyclophosphamide, vincristin, and prednisolone (THP-COP) was not effective for his lymphoma. He suffered from cardiac tamponade and died at 5 months after diagnosis. Autopsy revealed a large cardiac tumor, extensive epicardial infiltration, tiny tumors in the lung and pancreas, but no lymphadenopathy, the combination of which suggested a primary cardiac lymphoma. Immunohistochemistry for p53 protein showed nuclear staining of more than 50% of the lymphoma cells. In situ hybridization for EBER-1 was negative. Rearrangement of c-myc gene and overexpression of p53 protein are usually observed in Burkitt's lymphoma and some cases of high grade lymphomas including AIDS-associated non-Hodgkin lymphomas. In this case the association of these molecular findings and resistance to chemotherapy is suggested.

Aged↗
PubMed1997

Radiation dosage reduction in general dental practice using digital intraoral radiographic systems.

This report describes the radiation dosage reduction possible in the general dental practice with two CCD (charge-coupled device)-based intraoral radiographic systems: the RVG-S (Trophy Radiologie, Vincennes, France) and the Sens-A-Ray (Regam Medical Systems, Sundsvall, Sweden). Radiation dosages (air-kerma; Gy) necessary for obtaining clinically acceptable images were measured at the cone tip using an ionization chamber type 660-1 (Nuclear Associates, Victoreen, Inc., Carle Place, New York, USA). When the RVG-S was used with an Oramatic 70 (Trophy Radiologie) X-ray generator, dosages at the cone tip ranged from 322 to 612 microGy. These corresponded to 40-60% of the dosages necessary when using Ektaspeed dental X-ray film (Eastman Kodak, Rochester, New York, USA) with a Heliodent 70 (Siemens, Erlangen, Germany) X-ray generator. At 60 kVp, the Sens-A-Ray reduced the dosage in the order of 30% compared with Ektaspeed dental X-ray film. Reduction in radiation dosage is one of the benefits of digital intraoral radiographic systems in general dental clinics. The RVG-S provides greater dose savings than does the Sens-A-Ray.

Evaluation Studies as Topic↗
PubMed1996

A novel kinase cascade mediated by mitogen-activated protein kinase kinase 6 and MKK3.

A cDNA encoding a novel member of the mitogen-activated protein kinase kinase (MAPKK) family, MAPKK6, was isolated and found to encode a protein of 334 amino acids, with a calculated molecular mass of 37 kDa that is 79% identical to MKK3. MAPKK6 was shown to phosphorylate and specifically activate the p38/MPK2 subgroup of the mitogen-activated protein kinase superfamily and could be demonstrated to be phosphorylated and activated in vitro by TAK1, a recently identified MAPKK kinase. MKK3 was also shown to be a good substrate for TAK1 in vitro. Furthermore, when co-expressed with TAK1 in cells in culture, both MAPKK6 and MKK3 were strongly activated. In addition, co-expression of TAK1 and p38/MPK2 in cells resulted in activation of p38/MPK2. These results indicate the existence of a novel kinase cascade consisting of TAK1, MAPKK6/MKK3, and p38/MPK2.

Amino Acid Sequence↗
PubMed1996

TAB1: an activator of the TAK1 MAPKKK in TGF-beta signal transduction.

Transforming growth factor-beta (TGF-beta) regulates many aspects of cellular function. A member of the mitogen-activated protein kinase kinase kinase (MAPKKK) family, TAK1, was previously identified as a mediator in the signaling pathway of TGF-beta superfamily members. The yeast two-hybrid system has now revealed two human proteins, termed TAB1 and TAB2 (for TAK1 binding protein), that interact with TAK1. TAB1 and TAK1 were co-immunoprecipitated from mammalian cells. Overproduction of TAB1 enhanced activity of the plasminogen activator inhibitor 1 gene promoter, which is regulated by TGF-beta, and increased the kinase activity of TAK1. TAB1 may function as an activator of the TAK1 MAPKKK in TGF-beta signal transduction.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Further association study on dopamine D2 receptor variant S311C in schizophrenia and affective disorders.

The dopamine D2 receptor gene is a candidate gene for schizophrenia because the potency of certain neuroleptics correlates with their affinity for this receptor. Case-control studies in 291 schizophrenics, 78 patients with affective disorders, and 579 controls on an association of a molecular variant of S311C of the dopamine D2 receptor with psychiatric disorders were conducted. The frequency of individuals with S311C was significantly higher in schizophrenics with the absence of negative symptoms (17.1%, P < 0.00001), but similar in schizophrenics with the presence of negative symptoms (5.7%, P = 0.46) when compared with the controls (4.1%). The frequency of S311C was significantly higher in familial schizophrenics from one local area but not in those from other areas. It was significant that S311C was frequently present in patients with mood-incongruent psychotic affective disorders (33.3%, P < 0.0001), but not in those with other affective disorders. These data suggest that S311C might be one of the genetic factors for symptomatic dimensions of delusions and hallucinations and might be involved in underlying clinical heterogeneity in schizophrenia and affective disorders.

Adult↗
PubMed1996

T1 and T2 squamous cell carcinomas of the floor of the mouth: results of brachytherapy mainly using 198Au grains.

PURPOSE: To investigate the effectiveness of brachytherapy provided by this institution over a 25-year period, and to specifically verify the efficacy of 198Au grain therapy, this study evaluated the outcomes in patients given brachytherapy for T1 and T2 squamous cell carcinoma (SCCs) of the floor of the mouth. METHODS AND MATERIALS: A retrospective analysis of data from 90 patients with T1 and T2 SCCs of the floor of the mouth who underwent brachytherapy between 1965 and 1989. Therapy mainly consisted of 198Au grain implants with or without external irradiation. As for the brachytherapeutic source, 15 patients were treated with radon seeds, 60 with 198Au grains, 10 with radium needles, 3 with cobalt needles, and 2 with iridium hairpins. Based on the 1987 International Union Against Cancer (UICC) classification, the SCC stagings and number of cases per staging follow: Stage I (T1N0), 21 cases; Stage II (T2N0), 55 cases; and Stage III-IV (T1-2N1-2), 14 cases. The minimum follow-up time was 3 years. RESULTS: The local control rates of these SCCs, based on tumor size, were 89% for T1 lesions, 76% for T2a (< or = 3 cm) lesions, and 56% for T2b (> 3 cm) lesions, and 82% for T1-2 lesions without a gingival involvement, in contrast to 55% for lesions with a gingival involvement (p < 0.05). The 5-year, cause-specific survival rates by staging were 95% for T1N0, 79% for T2N0, and 54% for T1-2N1-2. For patients given 198Au grain brachytherapy, local control was achieved in 93% of the T1 lesions, 79% of the T2a lesions, and in 56% of the T2b lesions. Further, the incidence of severe complications requiring surgery was low (5%). CONCLUSIONS: For T1N0 and T2aN0 SCCs of the floor of the mouth, excluding lesions with a gingival involvement, 198Au grain brachytherapy alone or in combination with external radiotherapy was found to be efficacious.

Adult↗
PubMed1996

Triterpenoid glycosides from bark of Meliosma lanceolata.

From the bark of Meliosma lanceolate, nine triterpenoid glycosides including the 28-O-beta-D-glucopyranosyl ester of bayogenin-3-O-beta-D-glucuronopyranoside, its 4'-O-beta-D-galactopyranoside and 4'-O-alpha-L-arabinopyranoside were isolated and the structures characterized along with that of 28-O-beta-D-glucopyranosyl-bayogenin-3-O-beta-D-4'-anhydro-4', 5'-didehydroglucuronopyranoside. Bisdesmosidic triosides of hederagenin were obtained as minor components.

Carbohydrate Sequence↗