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Biomedical subjects

T Amano

Publications and source records attributed to T Amano.

At least 91 records · Page 5Linked to original sources

[A case of ileus as a late complication of an ileal conduit in a patient with primary signet ring cell carcinoma of the bladder].

A 69-year-old man visited our hospital with a complaint of dysuria. Intravenous excretory urography, ultrasonography and CT scan showed a tumor at the base of the bladder and the prostate. Transrectal needle biopsy revealed signet ring cell carcinoma. Radical cystectomy and ileal conduit were performed, and a histological diagnosis was a primary signet ring cell carcinoma of the bladder. No recurrence or metastasis was found either on ultrasonography or CT scan at 26 months after the operation. He suddenly suffered from severe abdominal pain, and died of hypovolemic shock by ileus as a late complication of an ileal conduit at 27 months after the operation. An ileus with extensive necrosis of small intestine and cancer recurrence at the junction of the ureter and ileal conduit were observed at autopsy.

Aged↗

[A case of effective urgent irradiation therapy for metastatic spine tumor].

A 74-year-old man noticed weakness in bilateral lower limbs 2 months prior to admission. The weakness had rapidly progressed and he could not stand by himself on admission. All thoracic vertebral bodies showed mosaic pattern on T 2 weighted-image. At Th 10 and Th 11, two enhanced masses compressed spinal cord posteriorly. Basal-serum tumor markers, such as LDH, ALP, total-acid phosphatase and prostatic acid phosphatase were elevated, metastatic spine tumor from prostatic carcinoma was suspected. Biopsy specimen from its prostate revealed low differentiated adenocarcinoma. Because sphincter dysfunction progressed rapidly after admission, we started 3 Gy/day irradiation within 24 hr from its appearance targeting both Th 10 to L 1 vertebral bodies and the prostate in total 30 Gy. The clinical symptoms started to resolve immediately, and the disappearance completely within 7 months. This case illustrated that urgent irradiation was effective for broad metastatic spinal tumor with rapidly progressive neurological deficits.

Adenocarcinoma↗

[Homogenous low-density lipoprotein assay in type III hyperlipoproteinemia].

To investigate whether homogenous analysis of serum low-density lipoprotein cholesterol(LDL-C) was applicable in type III hyperlipoproteinemic subjects, 3 reagents were used to estimate LDL-C in 2 cases with apoE 2/2 phenotype. Each measurements were compared to LDL-C levels by ultracentrifugation(density: 1.019-1.063). LDL-C levels by homogenous analysis with any of the reagents were higher than those by ultracentrifugation, and the difference was varied between the reagents: +14-24% by LDL-EX, +29-55% by Cholestest LDL, and +89-115% by Determiner LDL-C. The cross-reaction by the reagents to intermediate density lipoprotein(IDL) and very low density lipoprotein(VLDL) cholesterol was studied in a case; 22% of cholesterol in these fractions was measured by LDL-EX, 32% by Cholestest LDL, and 110% by Determiner LDL-C. A part of the sample serum was stored at -60 degrees C for several days and melted for re-analysis of homogenous LDL-C levels. After the freezing process, IDL fraction pattern on electrophoresis had been changed and homogenous LDL-C levels by all reagents were different from the measurements of native serum. These results indicated that using reagents with low cross-reaction to IDL and VLDL fractions and careful sample handling are important in homogenous LDL-C analysis in type III hyperlipoproteinemia.

Aged↗

[A patient with motor neuron syndrome clinically similar to amyotrophic lateral sclerosis, presenting spontaneous recovery].

We report a patient with motor neuron syndrome similar to amyotrophic lateral sclerosis (ALS) and with spontaneous recovery. At the age 40, the woman developed progressive muscular weakness, atrophy and fasciculation in extremities. She also noted a dyspnea, tongue atrophy and dysphagia. A neurological examination 6 months after onset revealed i) a tongue atrophy and fasciculation, ii) diffuse muscule weakness and atrophy in face, neck and extremities, and iii) marked hyperreflexia in the four limbs and bilateral Babinski reflex, but iv) neither sensory disturbance nor ophthalmoplegia. Electromyogram (EMG) detected such denervation potentials as fibrillation potentials, fasciculation potentials, positive sharp waves and polyphasic or giant MUPs diffusely in the limb muscles. Peripheral nerve conduction study detected neither conduction block nor delay. Thus, she was diagnosed as suffering from ALS. However, since approximate 1 year after onset, her muscle weakness has gradually been getting better. Simultaneously, the dyspnea and dysphagia gradually improved. Two years after onset, an EMG examination detected chronic denervation potentials in the left musculus sternocleidomastoideus and a few on-going denervation potentials in the left musculus extensor carpi radialis, but no denervation potentials in other limb muscles. Fasciculation potentials were found in tongue muscles. Thus, the present case was thought to have a reversible motor neuron syndrome clinically quite similar to ALS. A mild increase in IgE (346 U/ml) and a low-titer IgM-class anti-GM1 antibody were found in her serum though its pathological significance was uncertain. Any immunological aberrance may account for the pathogenesis. It should be noted that clinically diagnosed cases of ALS may rarely recover spontaneously.

Adult↗

Hypernuclear acetylation in atherosclerotic lesions and activated vascular smooth muscle cells.

Recent studies have implicated acetylation of several nuclear proteins such as histones and p53 on their epsilon-portion of lysine residues in eukaryotic transcription. Here we raised a specific polyclonal antibody against epsilon-acetylated lysine. Using the antibody, we detected hypernuclear acetylation (HNA) in atherosclerotic vascular smooth muscle cells (VSMCs). Thrombin, a humoral factor known to cause activation and proliferation of VSMCs, strongly potentiated HNA in cultured VSMCs. MAP kinase pathway and a signal coactivator CREB binding protein (CBP) were involved in thrombin-induced HNA of VSMCs. Our results suggest that coactivators cooperating with signal-dependent transcription activators play an important role in atherosclerogenesis via HNA in VSMCs.

Acetylation↗

Identification and characterization of Mg2+ binding sites in isolated alpha and beta subunits of H(+)-ATPase from Bacillus PS3.

The properties of the nucleotide binding sites in the isolated beta and alpha subunits of H(+)-ATPase from Bacillus PS3 (TF1) have been examined by studying the EPR properties of bound VO(2+), which is a paramagnetic probe for the native Mg2+ cation cofactor. The amino acid ligands of the VO2+ complexes with the isolated beta subunit, with the isolated alpha subunit, with different mixtures of both alpha and beta subunits, and with the catalytic alpha 3 beta 3 gamma subcomplex have been characterized by a combination of EPR, ESEEM, and HYSCORE spectroscopies. The EPR spectrum of the isolated beta subunit with bound VO2+ (1 VO2+/beta) is characterized by (51)V hyperfine coupling parameters (A( parallel) = 168 x 10(-)(4) cm(-)(1) and A( perpendicular) = 60 x 10(-)(4) cm(-)(1)) that suggest that VO2+ binds to the isolated beta subunit with at least one nitrogen ligand. Results obtained for the analogous VO2+ complex with the isolated alpha subunit are virtually identical. ESEEM and HYSCORE spectra are also reported and are similar for both complexes, indicating a very similar coordination scheme for VO2+ bound to isolated alpha and beta subunits. In the isolated beta (or alpha) subunit, the bound VO2+ cation is coordinated by one nitrogen ligand with hyperfine coupling parameters A( parallel)((14)N) = 4.44 MHz, and A( perpendicular)((14)N) = 4.3 MHz and quadrupole coupling parameters e(2)()qQ approximately 3.18 MHz and eta approximately 1. These are typical for amine-type nitrogen ligands equatorial to the VO2+ cation; amino acid residues in the TF1 beta and alpha subunits with nitrogen donors that may bind VO2+ are reviewed. VO2+ bound to a mixture of alpha and beta subunits in the presence of 200 mM Na2SO4 to promote the formation of the alpha 3 beta 3 hexamer has a second nitrogen ligand with magnetic properties similar to those of a histidine imidazole. This situation is analogous to that in the alpha 3 beta 3 gamma subcomplex and in the whole TF1 enzyme [Buy, C., Matsui, T., Andrianambinintsoa, S., Sigalat, C., Girault, G., and Zimmermann, J.-L. (1996) Biochemistry 35, 14281-14293]. These data are interpreted in terms of only partially structured nucleotide binding sites in the isolated beta and alpha subunits as compared to fully structured nucleotide binding sites in the alpha 3 beta 3 heterohexamer, the alpha 3 beta 3 gamma subcomplex, and the whole TF1 ATPase.

Animals↗

alpha3beta3gamma complex of F1-ATPase from thermophilic Bacillus PS3 can maintain steady-state ATP hydrolysis activity depending on the number of non-catalytic sites.

Homogeneous preparations of alpha(3)beta(3)gamma complexes with one, two or three non-competent non-catalytic site(s) were performed as described [Amano, Hisabori, Muneyuki, and Yoshida (1996) J. Biol. Chem. 271, 18128-18133] and their properties were compared with those of the wild-type complex. The ATPase activity of the complex with three non-competent non-catalytic sites decayed rapidly to an inactivated state, as reported previously [Matsui, Muneyuki, Honda, Allison, Dou, and Yoshida (1997) J. Biol. Chem. 272, 8215-8221]. In contrast, the complex with one or two non-competent non-catalytic sites displayed a substantial steady-state phase activity depending on the number of non-competent non-catalytic sites in the complex. This result indicates that one competent non-catalytic site can maintain the continuous catalytic turnover of the enzyme and can potentially relieve all three catalytic sites from inhibition by MgADP(-). Furthermore, the results suggest that the interaction between three non-catalytic sites might not be as strong as that between catalytic sites, which are all strictly required for a continuous catalytic turnover.

Adenosine Triphosphate↗

Cross-linking of two beta subunits in the closed conformation in F1-ATPase.

In the crystal structure of mitochondrial F1-ATPase, two beta subunits with a bound Mg-nucleotide are in "closed" conformations, whereas the third beta subunit without bound nucleotide is in an "open" conformation. In this "CCO" (beta-closed beta-closed beta-open) conformational state, Ile-390s of the two closed beta subunits, even though they are separated by an intervening alpha subunit, have a direct contact. We replaced the equivalent Ile of the alpha3beta3gamma subcomplex of thermophilic F1-ATPase with Cys and observed the formation of the beta-beta cross-link through a disulfide bond. The analysis of conditions required for the cross-link formation indicates that: (i) F1-ATPase takes the CCO conformation when two catalytic sites are filled with Mg-nucleotide, (ii) intermediate(s) with the CCO conformation are generated during catalytic cycle, (iii) the Mg-ADP inhibited form is in the CCO conformation, and (iv) F1-ATPase dwells in conformational state(s) other than CCO when only one (or none) of catalytic sites is filled by Mg-nucleotide or when catalytic sites are filled by Mg2+-free nucleotide. The alpha3beta3gamma subcomplex containing the beta-beta cross-link retained the activity of uni-site catalysis but lost that of multiple catalytic turnover, suggesting that open-closed transition of beta subunits is required for the rotation of gamma subunit but not for hydrolysis of a single ATP.

Adenine Nucleotides↗

Intrathoracic omental herniation through the esophageal hiatus: report of a case.

We report herein an extremely rare case of intrathoracic omental herniation through the esophageal hiatus. In fact, according to our review of the literature, only eight other cases have been reported, most of which were misdiagnosed as mediastinal lipoma after being identified as an intrathoracic mass. We report herein the ninth case of intrathoracic omental herniation through the esophageal hiatus. A 54-year-old obese woman was admitted to our hospital for investigation of a chest roentgenographic abnormality. She was asymptomatic, and her physical examination and laboratory data were all within normal limits. Her chest X-ray demonstrated a large, sharply-defined mass, and a computed tomography scan of the thorax indicated a large mediastinal mass with fat density. A thoracotomy was performed under the diagnosis of a mediastinal lipoma which revealed an encapsulated fatty mass, 10x7.5x6 cm in size, that proved to be an omental herniation through the esophageal hiatus. There was no herniation of the stomach or intestines into the thorax. The esophageal hiatus was repaired after the omental mass and hernia sac had been resected. This case report serves to demonstrate that whenever a mass of fat density is recognized in the lower thorax, an omental herniation should be borne in mind as a possible differential diagnosis.

Diagnosis, Differential↗

Inhibition by aripiprazole of dopaminergic inputs to striatal neurons from substantia nigra.

RATIONALE: Aripiprazole (OPC-14597) elicits both dopamine D(2) agonist and antagonist activities on dopaminergic neurons of the ventral tegmental area and nucleus accumbens neurons, respectively. However, the electrophysiological action of this drug on the striatal neurons is not clear. OBJECTIVE: Therefore, the present electrophysiological study was performed to determine if aripiprazole modified the striatal neurons as a D(2) receptor agonist or antagonist. METHODS: Spikes elicited by stimulation of pars compacta of the substantia nigra (SN) were extracellularly recorded from the striatal neurons with a glass microelectrode attached along a seven- barreled micropipette. Each barrel was filled with aripiprazole, quinpirole (D(2) receptor agonist), domperidone (D(2) receptor antagonist), glutamate or 2 M NaCl. The drugs were microiontophoretically applied on the neurons being recorded. RESULTS: The effects of aripiprazole on SN stimulation-induced spikes of striatal neurons that were inhibited by domperidone were examined. Microiontophoretic application of aripiprazole inhibited spikes elicited by SN stimulation in all 18 neurons tested in a dose-dependent manner. In addition, quinpirole-induced firing was inhibited by aripiprazole in all ten neurons tested. However, glutamate-induced spontaneous firing was not affected by aripiprazole in any of the ten neurons tested. CONCLUSIONS: These findings suggest that aripiprazole acts as a dopamine D(2) receptor antagonist on striatal neurons receiving excitatory inputs from the SN.

Animals↗

Immune response against protozoal and nematodal infection in mice with underlying Schistosoma mansoni infection.

Schistosoma mansoni infection induces T helper (Th) 2-dominant immune response in mice not only to S. mansoni itself but also to other coexisting antigens. In the present study, we challenged S. mansoni-infected mice with the intestinal nematode, Strongyloides venezuelensis, and the intracellular protozoa, Leishmania major to see whether such Th2-dominant immune responses alter susceptibility of the host to other concomitant parasitic infections. The recovery of S. venezuelensis adult worms from the small intestine was significantly decreased by S. mansoni infection, and the protection to S. venezuelensis appeared to act on migrating larvae. Antibodies elicited by S. mansoni infection showed cross-binding to third-stage larvae antigen of S. venezuelensis. On the other hand, S. mansoni infection did not affect the outcome of L. major infection in both susceptible BALB/c and resistant C57BL/6 mice. Popliteal lymph node cells of BALB/c mice expressed mRNA for interleukin (IL)-10 rather than IL-4, regardless of S. mansoni infection, and those of C57BL/6 mice expressed IFN-gamma mRNA upon L. major antigen stimulation, even in S. mansoni-infected mice. Our findings suggest that Th2-dominant immune response induced by S. mansoni protects mice from intestinal helminthic infections, whereas they do not always modulate protozoal infections.

Animals↗

The noncatalytic site-deficient alpha3beta3gamma subcomplex and FoF1-ATP synthase can continuously catalyse ATP hydrolysis when Pi is present.

We investigated ATP hydrolysis by a mutant (DeltaNC) alpha3beta3gamma subcomplex of F0F1-ATP synthase from the thermophilic Bacillus PS3 that is defective in the noncatalytic nucleotide binding sites. This mutant subcomplex was activated by inorganic phosphate ions (Pi) and did not show continuous ATP hydrolysis activity in the absence of Pi. Pi also activated the wild-type alpha3beta3gamma subcomplex in a similar manner. Sulphate activated wild-type alpha3beta3gamma but not DeltaNC alpha3beta3gamma, indicating that Pi activation did not involve noncatalytic sites but that sulphate activation did. Pi also activated ATP hydrolysis and coupled proton translocation by the wild-type and DeltaNC F0F1-ATP synthases reconstituted into vesicle membranes.

Adenosine Triphosphate↗

Retroperitoneal hemorrhage due to spontaneous rupture of adrenal myelolipoma.

BACKGROUND: A very rare case of retroperitoneal bleeding due to spontaneous rupture of a large adrenal myelolipoma in a 62-year-old woman is reported. METHODS/RESULTS: She consulted the emergency room of the Nagano Red Cross Hospital with a complaint of sudden left flank pain. A computerized tomography (CT) scan revealed a tumor with areas of fat density and hematoma in the left retroperitoneal space. After her general condition improved, an operation was performed. The tumor strongly adhered to the left kidney and a left nephrectomy with the tumor was curative. Histologic diagnosis was adrenal myelolipoma. No blood transfusion was required. CONCLUSIONS: A CT scan is very useful in the pre-operative diagnosis of adrenal myelolipoma with retroperitoneal hemorrhage. Watch and wait treatments before operation and nephrectomy with adhered tumor are safe and curative.

Adrenal Gland Neoplasms↗

Effects of scatter and attenuation correction on quantitative analysis of beta-CIT brain SPET.

The aim of this study was to evaluate the effects of scatter correction (SC) and attenuation correction (AC) on the quantification of dopamine transporters using 123I-beta-CIT brain SPET images. Quantitative analysis was carried out using static SPET images obtained 23 h after injection. We calculated V3" [(striatal-occipital)/occipital ratio] values from images without correction, with AC, and with SC and AC. Two types of regions of interest (ROI) were placed on the striatum: a small square ROI and a larger ROI containing most of the striatum. After validating the correction method in a phantom experiment, a human study was carried out involving eight normal volunteers and 15 patients. The larger ROI yielded smaller V3" values. The effect of attenuation correction was modest, whereas that of scatter correction was marked. It was shown that beta-CIT SPET quantification was affected by the size of the ROI, photon scattering and attenuation, and that scatter and attenuation correction improved the accuracy of the quantification. Methodological standardization in image processing and the type of ROI should be considered when a multi-centre trial is planned.

Aged↗