Search PubMed⌕ Search

Biomedical subjects

H Matsuda

Publications and source records attributed to H Matsuda.

At least 433 records · Page 24Linked to original sources
PubMed1999

[Application of SPECT to child neurology].

SPECT is a noninvasive functional neuroimaging method widely used even in child neurology because it can be easily implemented in routine clinical studies. Normal brain perfusion SPECT images in children change with brain maturation and differ from those in adults; for example, the blood flow is lower in the cerebellum than in the cerebrum. New methods have been developed to measure the cerebral blood flow without blood sampling and to perform statistical parametric mapping after spatial normalization of SPECT images to standard brain. They are applied to functional disorders such as autism and learning disorders. Neurotransmission imagings using SPECT are also available to visualize the benzodiazepine and dopamine systems; an early application of insurance is expected.

Adult↗
PubMed1999

[Potential role of angiotensin receptor antagonists in renal protection].

Recent clinical studies have established an important role of angiotensin converting enzyme inhibitors (ACE-I) as a tool for renal protection. Although angiotensin receptor antagonists (AII-A) share the common property with ACE-I with regard to blockade of angiotensin activity via angiotensin type 1 receptors (AT1), AII-A is also reported to stimulate AT2 that plausibly activates nitric oxide production within renal medulla and augments synthesis of vasodilatory P450-metabolites in renal afferent arterioles. In contrast, AII-A is reported to have no effect on bradykinin activity. Results obtained in experimental animals indicate that AII-A effectively prevents the progression of renal injury. Several clinical studies are in progress, and the preliminary results suggest that AII-A has potent renal protective action in a variety of renal disorders.

Angiotensin Receptor Antagonists↗
PubMed1999

[Deficit of language comprehension in a child with semantic-pragmatic disorder--dissociation between the phonemic and semantic processing abilities].

We studied the language comprehension deficit of a 11-year-old child with a semantic-pragmatic disorder. We used an original test battery using abstract nouns common to the tasks of repetition, reading aloud, auditory comprehension and comprehension of written words. Although he could repeat and read aloud words as good as normal controls, he could not choose correct pictures from semantically or phonemically resembling pictures by listening to or reading target words. This test demonstrated the dissociation between his phonemic and semantic processing abilities. An examination of the cerebral blood flow with SPECT suggested that the dysfunction of the left temporal lobe caused the deficit in language comprehension.

Brain↗
PubMed1999

[Reduction of the influence of the liver uptake to the myocardial uptake on technetium-99m myocardial SPECT; usefulness and problems of a mask processing method].

The aim of this study is to evaluate the usefulness of a mask processing method for obtaining the true myocardial tracer distribution by eliminating the influence of the liver uptake to the myocardial uptake on myocardial SPECT images by using technetium-99m (99mTc) blood flow agents. A SPECT imaging was performed with a two-head SPECT system (GCA-7200A/DI) in both phantom and clinical studies. The mask processing method was applied to the reconstructed and projection images. The phantom consisted of heart, lung, liver and spine. A defect was located in the inferior wall of the left ventricle and other parts of the heart and liver were filled with 99mTc solution. For clinical study 10 patients with difficulty in the interpretation of the inferior wall were selected for the evaluation of usefulness of the mask method. In the phantom study, the mask processing method applied to the reconstructed images was able to remove the overlapped liver from the heart, but was not able to remove the influence of the liver uptake to the myocardial uptake. Nevertheless, the mask processing method applied to the projection images successfully eliminated not only the overlapped liver but also the influence of the liver uptake to the myocardial uptake. In the clinical study, the liver uptake could be removed from the uptake in the inferior wall in 8 of 10 patients with the mask processing methods. In 2 patients, the overlapped liver uptake could not be eliminated from the uptake in the inferior wall because the distance between the liver and heart was too short. The mask processing method applied to the projection images was thought to be superior to that applied to the reconstruction images in both phantom and clinical studies. The mask processing method, especially applied to the projection images, seems to be useful for the elimination of the liver uptake from the inferior wall of the myocardium on myocardial SPECT images using 99mTc blood flow agents.

Artifacts↗
PubMed1999

SPECT image analysis using statistical parametric mapping in patients with Parkinson's disease.

UNLABELLED: This study investigated alterations in regional cerebral blood flow (rCBF) in patients with Parkinson's disease using statistical parametric mapping (SPM). METHODS: Noninvasive rCBF measurements using 99mTc-ethyl cysteinate dimer (ECD) SPECT were performed on 28 patients with Parkinson's disease and 48 age-matched healthy volunteers. The Parkinson's disease patients were divided into two groups, 16 patients with Hoehn and Yahr stage I or II and 12 patients with Hoehn and Yahr stage III or IV. We used the raw data (absolute rCBF parametric maps) and the adjusted rCBF images in relative flow distribution (normalization of global CBF for each subject to 50 mL/100 g/min with proportional scaling) to compare these groups with SPM. RESULTS: In patients with stage I or II Parkinson's disease, we found a diffuse decrease in absolute rCBF in the whole brain with sparing of the central gray matter, hippocampus and right lower temporal lobe compared with healthy volunteers. Adjusted rCBF increased in both putamina and the right hippocampus. In patients with stage III or IV disease, rCBF decreased throughout the whole brain. Adjusted rCBF increased bilaterally in the putamina, globi pallidi, hippocampi and cerebellar hemispheres (dentate nuclei) and in the left ventrolateral thalamus, right insula and right inferior temporal gyrus. CONCLUSION: SPM analysis showed that significant rCBF changes in Parkinson's disease accompanied disease progression and related to disease pathophysiology in the functional architecture of thalamocortex-basal ganglia circuits and related systems.

Adult↗
PubMed1999

[First brain dead donor heart transplantation under new legislation in Japan and future aspects of heart transplantation in Japan].

After the brain death and organ transplantation law was settled in 1997, the first case of heart transplantation (HTx) was carried out successfully. The patient was 47 year-old male with hypertrophic cardiomyopathy of dilated phase and on Novacor Implantable LVAS for 4 months. The distance from the donor hospital was about 200 km taking 2 hours for transport, and total ischemic time was 3 hours and 24 minutes. The post-transplant course was smooth. The patient was discharged on 75 postoperative day. We described current status of HTx in Japan and worldwide and discussed current problems and future aspects of HTx in Japan.

Brain Death↗
PubMed1999

Human antibody isotype responses to Schistosoma japonicum egg antigen.

Schistosoma japonicum-infected subjects from Hubei province of China were investigated to determine the class and subclass of the antibody response to soluble egg antigen (SEA), using an enzyme-linked immunosorbent assay. The subjects were 50 acute and 55 chronic cases. In acute cases, the mean OD values for IgA, IgE and IgG3 were very high, while the positive ratios of IgA and IgE were only 78% and 74%, respectively. The positive ratios of IgG, IgM, IgG1, IgG3 and IgG4 were all above 90%. In chronic cases, the mean OD values for IgG, IgG3 and IgG4 were very high, and the positivity rates of IgG, IgG1, IgG3 and IgG4 were all above 90%. Comparing the two study groups, the mean OD values of IgM, IgA, IgE were higher in acute cases than those of chronic cases (p < 0.0001), while the mean OD values of IgG, IgG4 were higher in chronic cases than in acute cases (p < 0.05). The mean OD values of IgG3 in both groups were high and those of IgG2 in both groups were low.

Acute Disease↗
PubMed1999

Making High-level Queries on Diverse Genome Data: A Structured Genome Document Database System Based on GXML and GQL.

Complete DNA sequences (genomes) and associated data are being made available worldwide at an astonishing rate. Through computer analysis of such data, molecular biologists hope to gain an overall understanding of the genome, such as by predicting large-scale gene networks. However, this is difficult because diverse genome data are scattered across many highly heterogeneous databases, and because existing database systems lack the facilities to expose and analyze functional relationships among the data. To address these problems, we propose a new type of genome database system. Since a genome can be thought of intuitively as a kind of 'document', our system uses a structured document language based on XML to effectively represent genomes and associated data. The information-rich structures of the genome documents help cope with data diversity and heterogeneity. A powerful query language is introduced that exposes important biological relationships among the genome data. We have obtained favorable results from several experiments, demonstrating the usefulness of our method in building a top-down view of genome functionality.

Journal Article↗
PubMed1999

Prominent increase of macrophage migration inhibitory factor in the sera of patients with uveitis.

PURPOSE: To investigate pathogenesis underlying endogenous uveitis, macrophage migration inhibitory factor (MIF) was quantified in sera of patients. METHODS: Sera were obtained from the 55 patients with uveitis (24 with Behçet's disease; 9 with Vogt-Koyanagi-Harada's [VKH] disease; 22 with sarcoidosis) and 58 healthy control subjects. MIF levels were determined by a human MIF enzyme-linked immunosorbent assay. RESULTS: The mean MIF levels in the sera of the patients with Behçet's disease, VKH disease, and sarcoidosis and of healthy control subjects were 60.4+/-9.0 (mean+/-SE) ng/ml, 16.5+/-2.9 ng/ml, 27.1+/-5.6 ng/ml, and 5.4+/-0.04 ng/ml, respectively. The average levels of MIF in the sera of uveitis patients were significantly higher (P < 0.0001) than those of healthy control subjects. The high levels of MIF were especially noted in patients with Behçet's disease at the ocular exacerbation stage and patients with sarcoidosis at the severe uveitis stage. CONCLUSIONS: Significant increase of MIF in sera was characteristic of uveitis, and MIF may be a usefull laboratory parameter to use to comprehend the clinical course of uveitis.

Behcet Syndrome↗
PubMed1998

Bcl-2 prevents caspase-independent cell death.

Nitric oxide (NO) is implicated in apoptosis and has both cytotoxic and cytoprotective effects. Exogenous NO induced the death of PC12 and HeLa cells via a process showing features of both apoptosis and necrosis, with chromatin condensation, nuclear compaction, and mitochondrial swelling. Activation of caspases was not observed during NO-induced cell death. In addition, cell death was not inhibited by peptide caspase inhibitors or by expression of p35, a baculovirus-encoded caspase inhibitor, indicating that NO-induced cell death was independent of caspases. NO-induced cell death was enhanced by Bax expression in a caspase-independent manner and prevented by the anti-cell death protein Bcl-2. Although Bcl-2 has previously been shown to prevent cell death by inhibiting caspase activation, these results indicate that it can also prevent cell death via a caspase-independent mechanism.

Adrenal Gland Neoplasms↗
PubMed1998

Bax interacts with the permeability transition pore to induce permeability transition and cytochrome c release in isolated mitochondria.

Cytochrome c release and the mitochondrial permeability transition (PT), including loss of the transmembrane potential (Deltapsi), play an important role in apoptosis. Using isolated mitochondria, we found that recombinant Bax and Bak, proapoptotic members of the Bcl-2 family, induced mitochondrial Deltapsi loss, swelling, and cytochrome c release. All of these changes were dependent on Ca2+ and were prevented by cyclosporin A (CsA) and bongkrekic acid, both of which close the PT pores (megachannels), indicating that Bax- and Bak-induced mitochondrial changes were mediated through the opening of these pores. Bax-induced mitochondrial changes were inhibited by recombinant Bcl-xL and transgene-derived Bcl-2, antiapoptotic members of the Bcl-2 family, as well as by oligomycin, suggesting a possible regulatory effect of F0F1-ATPase on Bax-induced mitochondrial changes. Proapoptotic Bax- and Bak-BH3 (Bcl-2 homology) peptides, but not a mutant BH3 peptide nor a mutant Bak lacking BH3, induced the mitochondrial changes, indicating an essential role of the BH3 region. A coimmunoprecipitation study revealed that Bax and Bak interacted with the voltage-dependent anion channel, which is a component of PT pores. Taken together, these findings suggest that proapoptotic Bcl-2 family proteins, including Bax and Bak, induce the mitochondrial PT and cytochrome c release by interacting with the PT pores.

Animals↗
PubMed1998

In vivo transfer of a beta 2-adrenergic receptor gene into the pressure-overloaded rat heart enhances cardiac response to beta-adrenergic agonist.

BACKGROUND: In the failing heart, the density and affinity of beta-adrenergic receptors in the myocardium both tend to decrease as the severity of cardiac dysfunction increases. If this suppression of beta-adrenergic receptors could be prevented or reversed, this could serve as a fundamental form of treatment for the failing heart. We report here a possible new therapeutic approach for the failing heart involving the transfer of the beta 2-adrenergic receptor (B2AR) gene. METHODS AND RESULTS: The B2AR cDNA was transfected in vivo to the concentric hypertrophied rat heart by intracoronary infusion with a hemagglutinating virus of Japan liposome method, and the transfected heart was transplanted into the abdomen of another rat. Four days after transfection, the sarcolemma of the cardiomyocytes was well labeled by immunohistochemical labeling. An overexpression of BAR of approximately 5 times in the heart (140 +/- 35 versus 24 +/- 3 fmol/mg protein for the transfected versus control hearts) was demonstrated by a ligand binding assay. The cardiac response of the transfected heart to isoproterenol was shown to be enhanced in a Langendorff perfusion system: After isoproterenol, developed pressure and maximal derivative of the left ventricle were greater than in the control heart (260 +/- 20 versus 230 +/- 10 mm Hg and 5500 +/- 300 versus 4500 +/- 300 mm Hg/s), and the minimal derivative of the left ventricle was remarkably smaller (-4500 +/- 300 versus -3300 +/- 200 mm Hg/s). CONCLUSIONS: These results indicate that in vivo transfection of the gene for B2AR enhances the cardiac response to isoproterenol in the pressure-overloaded rat heart (in which the disease causes a decrease in receptor density), suggesting that transfer of this gene by intracoronary infusion during cardiac arrest has potential as a novel therapeutic approach for failing hearts.

Adrenergic beta-Agonists↗
PubMed1998

Hybrid artificial lung with interleukin-10 and endothelial constitutive nitric oxide synthase gene-transfected endothelial cells attenuates inflammatory reactions induced by cardiopulmonary bypass.

BACKGROUND: Recently, the research on hybrid artificial organs such as heart, liver, and kidney has been reported to yield new possibilities for clinical use. However, there have been few reports on the practical use of a hybrid artificial lung, primarily due to difficulties in the concept for its application and techniques for cell attachment. In this study, we investigated the possibility for developing a novel strategy: a hybrid artificial lung with constitutive nitric oxide synthase (NOS) and interleukin (IL)-10 gene-transfected endothelial cells to attenuate inflammatory reactions induced by cardiopulmonary bypass. METHODS AND RESULTS: First, we performed an in vitro study to confirm the efficacy of our gene transfection into endothelial cells. Constitutive nitric oxide synthase and IL-10 cDNA were transfected into endothelial cells according to the hemagglutinating virus of Japan-liposome method. Levels of nitric oxide released from the endothelial constitutive NOS (ecNOS)-transfected endothelial cells were significantly higher than those of control cells (24 hours after the stimulation by lipopolysaccharide: 284.5 +/- 54.0 versus 95.7 +/- 27.9 mumol/L, P = 0.0001). On the other hand, IL-8 levels in the transfected endothelial cells were significantly lower than those in the control group (48 hours after stimulation by tumor necrosis factor-alpha: 3.1 +/- 2.4 versus 62.1 +/- 1.3 ng/mL, P = 0.0002), and IL-10 was detected in the transfected group but not in the control group. Next, we performed an in vivo study to evaluate the possibility of developing a hybrid artificial lung. One-hour partial cardiopulmonary bypass with this lung was established in rats undergoing femorofemoral bypass. Artificial lungs with no cells (group C; n = 5), that were coated with untreated endothelial cells (group E; n = 5), or that were coated with ecNOS and IL-10 gene-transfected endothelial cells (group T; n = 3) were used. At 45 minutes after the initiation of cardiopulmonary bypass, group T showed higher nitric oxide levels than groups C and E (T versus C versus E: 75.2 +/- 6.8 versus 67.2 +/- 4.3 versus 68.6 +/- 5.2 mumol/L, P = NS). The serum IL-8 levels just after cardiopulmonary bypass in group T were significantly lower than those in group C (1728 +/- 282 versus 4275 +/- 145 pg/mL, P = 0.0151). The Pao2 levels in group T just after weaning from cardiopulmonary bypass were significantly higher than those in group C (271.3 +/- 41.7 versus 136.6 +/- 12.3 mm Hg, P = 0.0362). CONCLUSIONS: These results demonstrate that a hybrid artificial lung with IL-10 and ecNOS gene-transfected endothelial cells inhibited IL-8 release and increased nitric oxide production. This suggests the possibility of developing a hybrid artificial lung capable of preserving native lung function by attenuating cardiopulmonary bypass-induced inflammatory reactions via inhibition of IL-8 release and enhanced nitric oxide production.

Animals↗
PubMed1998

Hepatoprotective, superoxide scavenging, and antioxidative activities of aromatic constituents from the bark of Betula platyphylla var. japonica.

The 50% aqueous methanolic extract from the bark of Betula platyphylla SUKATCHEV var. japonica (MIQ). HARA was found to show potent inhibitory activity on the liver-injury induced by CCl4 or D-galactosamine (D-GalN)/lipopolysaccharide as well as O2- scavenging and antioxidative activities. From the 50% aqueous methanolic extract, two new diarylheptanoids named betulaplatosides Ia (1) and Ib (2) and a new arylbutanoid named betulaplatoside II (3) were isolated together with seventeen known aromatic constituents. 1, 2, and two known diarylheptanoids [(5S)-5-hydroxy-1,7-bis-(4-hydroxyphenyl)-3-heptanone 5-O-beta-D-apiofurano-syl-(1-->6)-beta-D-glucopyranoside (6) and aceroside VIII (7)] showed protective activity against D-GalN-induced cytotoxicity in primary cultured rat hepatocytes. Furthermore, several aromatic constituents exhibited potent O2- scavenging and antioxidative activities.

Animals↗
PubMed1998

Detailed deletion mapping suggests the involvement of a tumor suppressor gene at 17p13.3, distal to p53, in the pathogenesis of lung cancers.

The short arm of chromosome 17 is one of the most frequently affected chromosomal regions in lung cancers, while there is solid evidence that the p53 gene at 17p13.1 is a target for frequent 17p deletions. In the present study, we re-evaluated 17p deletions in lung cancers by conducting a detailed analysis of the minimum deleted region(s) on 17p with reference to the p53 gene status in each 100 primary lung cancer cases. In addition to the p53 locus at 17p13.1, the presence of an independent, commonly deleted region(s) at 17p13.3 was identified. Furthermore, loss of heterozygosity (LOH) at 17p13.3 was shown to be even more frequent than that at 17p13.1 and it appeared to occur in the absence of p53 mutation and/or 17p13.1 deletion. These results suggest that in addition to the p53 gene at 17p13.1, an as yet unidentified tumor suppressor gene(s) residing at 17p13.3 might play a role in lung carcinogenesis possibly in an earlier phase than the p53 gene. This would warrant future studies to identify the putative tumor suppressor gene at 17p13.3 in order to gain a better understanding of the molecular pathogenesis of this fatal disease.

Adenocarcinoma↗
PubMed1998

Chloride concentration in cultured hippocampal neurons increases during long-term exposure to ammonia through enhanced expression of an anion exchanger.

The effects of long-term exposure to ammonia on [Cl-]i in cultured hippocampal neurons were examined. Ammonia increased the [Cl-]i time- (>/=24 h) and concentration- (>/=2 mM) dependently, resulting in a depolarizing shift of the equilibrium potential of the GABAA receptor-Cl- channel opening (EGABA). Such an effect of ammonia was diminished by the inhibitors of Cl-/HCO3- exchangers, 0.1 mM 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid (SITS) and 0.1 mM 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), and a carbonic anhydrase inhibitor, 2 mM acetazolamide, but not by a Na+/K+/2Cl-cotransport inhibitor, 50 microM bumetanide, suggesting an enhanced Cl-/HCO3- exchange activity by ammonia. The ammonia-induced increase in [Cl-]i was also abolished by the inhibitors of protein kinase C (PKC), 0.1 microM calphostin C and 10 microM 1-(5-isoquinolinyl-sulfonyl)-2-methylpiperazine dihydrochloride (H-7), and of transcription and de novo protein synthesis, 1 microM actinomycin D and 0.5 microg/ml cycloheximide, while a PKC activator, 0.1 h microM phorbor 12-myristate 13-acetate (PMA), increased the [Cl-]i. The mRNA level of the AE3 Cl-/HCO3- exchanger was increased by ammonia in a calphostin C- and H-7-sensitive manner. The AE3-like immunoreactivity was also increased by ammonia. These findings suggest that long-term exposure to ammonia increases the expression of AE3 through the activation of PKC, resulting in an increase in [Cl-]i in neurons and a reduction of inhibitory postsynaptic potentials.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1998

Hypoxic adaptation of the peptidergic innervation in the rat carotid body.

The abundance of substance P (SP)-, calcitonin gene-related peptide (CGRP)-, vasoactive intestinal polypeptide (VIP)-, and neuropeptide Y (NPY)-immunoreactive nerve fibers in the carotid body was compared between normoxic and chronically hypoxic rats (10% O2 and 3.0-4.0% CO2 for 3 months). The immunoreactive fibers appeared as thin processes with many varicosities, and were distributed mainly around the vasculatures. In the normoxic control carotid body, NPY fibers were more numerous than VIP, CGRP, and SP fibers. In the chronically hypoxic rats, the carotid body was enlarged several fold, and the mean absolute number of VIP and NPY fibers was 3.88 and 2.22 times higher than in the normoxic carotid body, respectively, although that of SP and CGRP fibers was not changed. When expressed as density per unit area of the parenchyma, the density of SP and CGRP fibers in the chronically hypoxic carotid body decreased significantly to under 50%, the density of VIP fibers increased significantly 1.80 times, and the density of NPY fibers were unchanged. Immunoreactivity for four neuropeptides was not found in the glomus cells of normoxic or chronically hypoxic carotid bodies. These results suggest that altered peptidergic innervation of the chronically hypoxic carotid body is one feature of hypoxic adaptation. Because these neuropeptides are vasoactive in nature, altered carotid body circulation may contribute to modulation of the chemosensory mechanisms by chronic hypoxia.

Adaptation, Physiological↗