Biomedical subjects

H Mori

Publications and source records attributed to H Mori.

At least 37 records · Page 2Linked to original sources

PubMed2004

Direct evidence for reversible diffusional phase change in nanometer-sized alloy particles.

Solid solubility in isolated nanometer-sized particles has been studied by in situ transmission electron microscopy using alloy particles in the Pb-Sn binary system. In approximately 17-nm-sized particles of a lead-56 at. % Sn solid solution, a phase change from a single phase of the lead solid solution to two phases, a lead solid solution and a tin-solid solution, takes place when the temperature is reduced from 110 degrees C to room temperature (RT). Furthermore, it is confirmed that this phase change could occur rather reversibly when the temperature is cyclically changed between 110 degrees C and RT. This observation provides direct evidence for reversible diffusional phase change in nanometer-sized alloy particles. It seems safe to conclude that the solubility limit of tin in lead is higher than 56 at. % at 110 degrees C, which is almost 5 times higher than the solubility limit of tin in bulk lead (i.e., 10 at. %).

Journal Article↗

PubMed2004

Nonlinear responses of electronic-excitation-induced phase transformations in GaSb nanoparticles.

We studied electronic-excitation-induced phase transformations in nanoparticles using transmission electron microscopy. GaSb particles excited by 75 keV electrons transform to two phases consisting of an antimony core and a gallium shell or an amorphous phase, or remain in the original crystalline phase, depending on particle size and/or temperature. It is suggested that such nonlinear responses of the phase transformations may arise from synergistic effects of bond instability, localized excitations, enhanced diffusivity, or thermal equilibrium in reactions.

Journal Article↗

PubMed2004

Malignant lymphoma with tumor thrombus in the portal venous system.

We report a case of malignant lymphoma presenting with tumor thrombus of the portal venous system. Computed tomography showed a mass in the portal vein and mesenteric lymphadenopathy. Filling defects in the dilated portal vein also were identified by angiography. This type of the lymphoma is extremely rare, but it should be considered in the differential diagnosis of portal vein thrombus.

Angiography, Digital Subtraction↗

PubMed2004

Aggressive natural killer-cell leukemia revisited: large granular lymphocyte leukemia of cytotoxic NK cells.

Aggressive natural killer-cell leukemia (ANKL) is a rare form of large granular lymphocyte leukemia, which is characterized by a systemic proliferation of NK cells. The clinical features of 22 ANKL cases were analyzed. Hepatomegaly (64%), splenomegaly (55%) and lymphadenopathy (41%) were also frequently observed. Leukemic cells were identified as CD1-, CD2+, surface CD3-, CD4-, CD5-, CD7+, CD8+/-, CD10-, CD11b+/-, CD13-, CD16+, CD19-, CD20-, CD25-, CD33(-), CD34-, CD38+, CD56+, CD122+, HLA-DR+ and TCR-. Two of the 16 cases examined for CD57 were positive and three of the seven cases examined for cytoplasmic CD3. Epstein-Barr virus was detected in the tumor cells of 11 of the 13 cases examined. No common cytogenetic abnormalities were identified and 6q anomaly was detected in only one. Three of 13 patients treated with chemotherapy containing anthracycline/anthraquinone attained complete remission, in contrast to none of the eight who were treated with regimens without anthracycline. Although the overall prognosis was poor with a median survival of 58 days, those who attained remission showed better prognosis (P=0.005). These findings suggest that ANKL is an entity of mature cytotoxic NK-cell neoplasms with distinct phenotype and disease presentations. Intensive treatment for ANKL may result in a better prognosis.

Adult↗

PubMed2004

Diffusion property following functional hemispherectomy in hemimegalencephaly.

Diffusion-tensor imaging (DTI), a unique magnetic resonance technique for analysis of diffusion-anisotropy of the brain, can identify subtle white matter changes in vivo. To investigate changes of truncated neurofibers, DTI was conducted prior to and following functional hemispherectomy in a female infant for refractory epilepsy associated with hemimegalencephaly. Anisotropy of the amputated pyramidal tract decreased relative to the unaffected side after surgery, which reflects secondary degeneration in neurofibers. In DTI applied to infants, differentiation between developmental changes and changes associated with the current phenomenon must be evaluated cautiously. Standardization of diffusion-tensor analysis of developmental change is desirable.

Adult↗

PubMed2004

Pharmacokinetics/pharmacodynamics of Y-700, a novel xanthine oxidase inhibitor, in rats and man.

The pharmacokinetics and pharmacodynamics of a novel xanthine oxidase (XO) inhibitor, Y-700, were evaluated in rats and healthy male volunteers. In a rat model of hyperuricemia, oral Y-700 (0.3-10 mg/kg) showed a more potent and a longer-lasting hypouricemic action than allopurinol. A single oral dosing of Y-700 (5, 20 or 80 mg) to volunteers caused a dose-dependent reduction of serum uric acid levels indicating close relationship to plasma concentrations of the compound. In addition, Y-700 was hardly excreted in urine but mainly excreted in feces in rats and volunteers. These results suggested that Y-700 is a new effective inhibitor of XO in rats and humans with high oral bioavailability being predominantly eliminated via the liver unlikely to allopurinol.

Administration, Oral↗

PubMed2004

Hypoxia as a factor for 67Ga accumulation in tumour cells.

Recent reports have demonstrated that hypoxia induces the up-regulation of transferrin receptor expression in tumour cells. Tumour cells take up 67Ga in the form of a 67Ga-transferrin complex via transferrin receptors. As a result, we attempted to determine the influence of hypoxic conditions on 67Ga uptake in tumour cells. B16 melanoma cells and LS180 colon cancer cells were incubated in 95% air/5% CO2 or 95% N2/5% CO2 for 1 h at 37 degrees C. Cellular uptake of 67Ga citrate was subsequently determined at 20, 40, 60 and 90 min. Uptake of the 67Ga-transferrin complex pre-chelated in vitro was similarly assessed. The effect of hypoxia on 67Ga binding to serum proteins was also investigated. Both B16 and LS180 cells displayed increased cellular uptake of 67Ga citrate in N2 gas in comparison to that in air (P < 0.0001). Hypoxia more prominently influenced cellular uptake of Ga-transferrin relative to that of 67Ga citrate (P < 0.0001). Hypoxia did not affect the percentages of 67Ga radioactivity bound to protein in medium supplemented with fetal calf serum, indicating that the results were not caused by the alteration of 67Ga-transferrin formation. These findings suggest the role of tissue hypoxia with respect to accumulation of 67Ga in tumours, which is likely mediated by transferrin receptors.

Adenocarcinoma↗

PubMed2004

Pathological study on the relationship between C4d, CD59 and C5b-9 in acute renal allograft rejection.

In order to evaluate the activation or inhibition of the later phases of classical complement cascade in renal allograft presenting with acute rejection, particularly with C4d deposition on the peritubular capillary (PTC), we observed the expression of CD59 and C5b-9 on the PTC. Subjective cases were divided into two groups, an acute rejection group, of 4 males and 6 females, and a normal donor group, of 5 males and 5 females. Renal biopsies were performed at the onset of acute rejection and at the transplant operation, before reperfusion. C4d deposition on PTC was found in three of 10 cases (30%) with biopsy proven acute rejection, whereas CD59 on PTC was positively expressed in all of the rejection cases. Although C5b-9 was not observed on PTC in the acute rejection group, it was intensively deposited on the tubular basement membrane (TBM) in five cases, including the three with positive C4d on PTC. In the normal donor group, CD59 on PTC was intensively observed, whereas C5b-9 was weakly expressed on TBM. CD59, a complement regulatory factor, works as an inhibitory factor against the formation of C5b-9, a membrane attack complex. From our data, we noted the dissociation between the depositions of C4d and C5b-9 on PTC. The substantially expressed CD59 on PTC may affect this dissociation between C4d and C5b-9 on PTC. The intensive deposition of C5b-9 on TBM in acute rejection cases may suggest an independent immunological injury attacking tubular cells.

Acute Disease↗

PubMed2004

Soybean isoflavones inhibit estrogen-stimulated gene expression in mouse uteri.

This study was performed to examine the inhibitory effects of soybean isoflavones on estrogen-stimulated gene expression of the uteri in ovarectomized mice. Especially when compared with the inhibitory effect of genistein and daidzein as aglycosides described in our previous report, subcutaneous administration of the glycoside genistin significantly decreased the levels of estradiol-17beta (E2)-induced expressions of c-jun, interleukin (IL)-1alpha and tumor necrosis factor (TNF)-alpha mRNAs (p < 0.005, p < 0.05 and p < 0.05, respectively) and seemingly proteins in the mice uteri, whereas the glycoside daidzin weakly inhibited E2-stimulated expressions of c-fos and IL-1alpha. Both genistin and daidzin seemed to have a weaker inhibitory effect than that of genistein and daidzein on the expression of estrogen-stimulated genes. It is suggested that those glycosides are naturally derived and generally absorbed from plant foods and might prevent E2-related endometrial carcinogenesis.

Animals↗

PubMed2004

[Pulmonary thromboendarterectomy for an elderly patient].

We describe a case of successful pulmonary thromboendarterectomy for an elderly patient. A 75-year-old female suffered from severe dyspnea in spite of administration of pulmonary vascular dilators and anticoagulants. Her pulmonary vascular resistance was 545 dyn x sec x cm(-5) and, her pulmonary angiogram and perfusion scan revealed that almost all branches of her right pulmonary artery were occluded. Pulmonary thromboendarterectomy was performed under cardiopulmonary bypass. A videoscope was employed to see inside of the pulmonary artery. Flexible aspirator chip was used to peed abnormal intima easily. A non-invasive intracranial oxygen saturation monitor was used for secure circulatory arrest. The duration of cardiopulmonary bypass was 101 minutes and minimum body temperature was 24.5 degrees C. Her symptoms improved markedly after operation, and she went back to the ordinary life. Pulmonary thromboendarterectomy was useful even for elderly patients under some modifications of the operative procedures.

Aged↗

PubMed2004

[Pulmonary embolectomy followed by lobectomy to treat for massive endobronchial bleeding; report of a case].

We describe a case of successful pulmonary embolectomy that required lobectomy to treat for endobronchial bleeding. Sixty-nine-year-old female got into shock required CPR during rehabilitation after replacement of femur head. Her enhanced computed tomography (CT) showed massive embolism in pulmonary artery. Emergency embolectomy was performed under cardiopulmonary bypass (CPB). A videoscope was employed to see inside the pulmonary artery. At the end of the CPB, endobronchial bleeding occurred. The right bronchus was occluded by balloon and CPB was weaned. The right lower lobectomy was done on the next day. She had got pyothorax by methicillin-resistant Staphylococcus aureus (MRSA), and has recovered after intravenous administration of antibiotics and continuous wash out of pleural space by saline containing 0.02% povidon-iodine. Postoperative scan showed no defects of blood flow and ventilation except resected lobe.

Aged↗

PubMed2003

Global metabolic response of Escherichia coli to gnd or zwf gene-knockout, based on 13C-labeling experiments and the measurement of enzyme activities.

An integrated study on cell growth, enzyme activities and carbon flux redistribution was made to investigate how the central metabolism of Escherichia coli changes with the knockout of genes in the oxidative pentose phosphate pathway (PPP). Mutants deficient in glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were constructed by disrupting the zwf and gnd genes and were grown in minimal media with two different carbon sources, such as glucose or pyruvate. It was shown that the knockout of either gnd or zwf gene did not affect the cell growth rate significantly, but the cellular metabolism was changed. While the specific substrate uptake rate and the specific carbon dioxide evolution rate for either mutant grown on glucose were higher than those obtained for the parent strain, these two rates were markedly decreased in mutants grown on pyruvate. The measurement of enzyme activities implied a significant change in metabolism, when alternative pathways such as the Entner-Doudoroff pathway (EDP) and the malic enzyme pathway were activated in the gnd mutant grown on glucose. As compared with the parent strain, the activities of phosphoglucose isomerase were increased in mutants grown on glucose but decreased in mutants grown on pyruvate. The metabolic flux redistribution obtained based on 13C-labeling experiments further indicated that the direction of the flux through the non-oxidative PPP was reversed in response to the gene knockout. Moreover, the knockout of genes caused an increased flux through the tricarboxlic acid cycle in mutants grown on glucose but caused a decrease in the case of using pyruvate. There was also a negative correlation between the fluxes through malic enzyme and isocitrate dehydrogenase in the mutants; and a positive correlation was found between the fluxes through malic enzyme and phosphoenolpyruvate carboxylase.

Carbohydrate Metabolism↗

PubMed2003

Autoantibodies to NMDA receptor in patients with chronic forms of epilepsia partialis continua.

BACKGROUND: Antibody-mediated and cytotoxic T cell-mediated pathogenicity have been implicated as the autoimmune pathophysiologic mechanisms in Rasmussen's encephalitis. METHODS: The authors investigated autoantibodies against the NMDA glutamate receptor (GluR) epsilon2 subunit and their epitopes in serum and CSF samples from 15 patients with chronic epilepsia partialis continua (EPC), 17 with West syndrome, 10 with Lennox-Gastaut syndrome, and 11 control subjects. RESULTS: In 15 patients with chronic EPC, we detected NMDA-type GluR epsilon2 autoantibodies in histologically proven Rasmussen's encephalitis (3/3 patients), clinical Rasmussen's encephalitis (6/7 patients), acute encephalitis/encephalopathy (2/3 patients), and nonprogressive EPC (2/2 patients). Serum IgM autoantibodies were found in the early phase of EPC and became negative later in four patients. The autoantibodies were not detected in West syndrome, Lennox-Gastaut syndrome, or controls. Among 10 patients with histologically proven or clinical Rasmussen's encephalitis, epitope analyses showed that the autoantibodies were predominantly against C-terminal epitopes and rarely against N-terminal epitope, with inconsistency in profile during the courses of disease. Epitope recognition spectrum of autoantibodies was broader in CSF than in serum, and the serum or CSF profile showed an increase in number of epitopes as disease progressed in some patients. CONCLUSIONS: The presence of autoantibodies against NMDA GluR epsilon2 suggests autoimmune pathologic mechanisms but is not a hallmark of Rasmussen's encephalitis. Patients with Rasmussen's encephalitis may have autoantibodies against several neural molecules, and these autoantibodies may be produced in the CNS after cytotoxic T cell-mediated neuronal damage.

Adolescent↗

PubMed2003

Features of the electron density in magnesium diboride: reconstruction from X-ray diffraction data and comparison with TB-LMTO and FPLO calculations.

Features of the electron density in MgB(2) reconstructed from room-temperature single-crystal X-ray diffraction intensities using a multipole model are considered. Topological analysis of the total electron density has been applied to characterize the atomic interactions in magnesium diboride. The shared-type B-B interaction in the B-atom layer reveals that both sigma and pi components of the bonding are strong. A closed-shell-type weak B-B pi interaction along the c axis of the unit cell has also been found. The Mg-B closed-shell interaction exhibits a bond path that is significantly curved towards the vertical Mg-atom chain ([110] direction). The latter two facts reflect two sorts of bonding interactions along the [001] direction. Integration of the electron density over the zero-flux atomic basins reveals a charge transfer of approximately 1.4 (1) electrons from the Mg atoms to the B-atom network. The calculated electric-field gradients at nuclear positions are in good agreement with experimental NMR values. The anharmonic displacement of the B atoms is also discussed. Calculations of the electron density by tight-binding linear muffin-tin orbital (TB-LMTO) and full-potential non-orthogonal local orbital (FPLO) methods confirm the results of the reconstruction from X-ray diffraction; for example, a charge transfer of 1.5 and 1.6 electrons, respectively, was found.

Journal Article↗

PubMed2003

Neuro-Behçet's disease: analysis of apparent diffusion coefficients.

Little is known about the diffusion properties of brain lesions in neuro-Behçet's disease (NBD). We looked at 19 NBD lesions (13 active, six chronic) in six patients, using diffusion-weighted MRI (DWI). We calculated the apparent diffusion coefficients (ADC) of the lesions and compared them with normal contralateral brain, expressing this ratio as relative ADC (rADC). The rADC was 1.29+/-0.33 in active and 1.44+/-0.47 in chronic lesions, i.e., significantly higher than in the control regions. Increased diffusivity in both active and chronic phases in NBD is different from the pattern in ischaemic infarcts, so that ADC analysis might be helpful for differentiating between these conditions.

Adolescent↗

PubMed2003

Three-dimensional white matter tractography by diffusion tensor imaging in ischaemic stroke involving the corticospinal tract.

Diffusion tensor MR imaging (DTI) provides information on diffusion anisotropy, which can be expressed with three-dimensional (3D) white matter tractography. We used 3D white matter tractography to show the corticospinal tract in eight patients with acute or early subacute ischaemic stroke involving the posterior limb of the internal capsule or corona radiata and to assess involvement of the tract. Infarcts and the tract were shown simultaneously, providing information on their spatial relationships. In five of the eight patients, 3D fibre tract maps showed the corticospinal tract in close proximity to the infarct but not to pass through it. All these patients recovered well, with maximum improvement from the lowest score on manual muscle testing (MMT) up to the full score through rehabilitation. In the other three patients the corticospinal tract was shown running through the infarct; reduction in MMT did not necessarily improve favourably or last longer, other than in one patient. As 3D white matter tractography can show spatial relationships between the corticospinal tract and an infarct, it might be helpful in prognosis of gross motor function.

Aged↗

PubMed2003

Identification of a non-S RNase, a possible ancestral form of S-RNases, in Prunus.

This study identifies and characterizes a basic non-S RNase in the styles with stigmas of sweet cherry (Prunus avium L.), a member of the Rosaceae subfamily Amygdaloideae, which has an RNase-based gametophytic self-incompatibility system. Internal sequences of putative non-S RNases (RNase PA1 and PA2) were determined, and a cDNA for PA1 was obtained. The deduced amino acid sequence of PA1 contained two conserved sequence motifs essential for T2/ S-type RNase activity. PA1 shows 20-30% sequence identity to S-RNases of Rosaceae, Solanaceae and Scrophulariaceae, and non-S RNases of higher plants. Transcription of the PA1 gene was specific to the styles with stigmas, and the gene was not expressed in other tissues. Although PA1 resembles RNase X2, a non-S RNase from Petunia inflata, the placement of PA1 and RNase X2 in the phylogenetic tree was quite different. Placement of PA1 was also distinct from that of rosaceous S-RNases, while RNase X2 was incorporated in the clade of S-RNases from the Solanaceae. The sole intron in the PA1 gene is located at a position equivalent to that of the second intron of amygdaloid S-RNase genes, and that of the only intron in most other S-RNase genes. Genomic Southern analysis revealed the presence of sequences homologous to PA1 in all of the other four Prunus species tested, suggesting that PA1 has an important physiological function. The significance of the discovery of PA1 is discussed in terms of the origin and evolution of S-RNases and self-incompatibility in Rosaceae.

Amino Acid Motifs↗

PubMed2003

Interfering mutations provide in vivo evidence that Escherichia coli SecE functions in multimeric states.

SecY, SecE and SecG form a heterotrimer, which functions as a protein translocation channel in Escherichia coli. The cytosolic loop of SecE contains a segment that is conserved among different organisms. Here we show that mutational alterations in this segment not only inactivate the SecE function but confer dominant interfering properties on the altered SecE molecule. Such effects were especially evident in mutant cells in which the requirement for SecE function was increased. Overproduction of SecE, but not of SecY, alleviated the dominant negative effects. These results suggest that the inactive SecE molecule sequesters wild-type SecE. It was also found that an amino acid substitution, D112P, in the C-terminal periplasmic region intragenically suppressed the dominant interference. These results are consistent with a notion that there is significant SecE-SecE interaction in vivo, in which the C-terminal region has an important role. The data hence suggest that dimeric SecE participates in the formation of the functional translocation channel.

Amino Acid Sequence↗