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Biomedical subjects

H Uchiyama

Publications and source records attributed to H Uchiyama.

At least 73 records · Page 4Linked to original sources
PubMed1998

Effect of thromboxane synthetase inhibitor on non-heart-beating donors in rat orthotopic liver transplantation.

BACKGROUND: The use of non-heart-beating donors could relieve donor organ shortage provided that the outcome of the recipients is not jeopardized. METHODS: In this study we evaluated the effect of thromboxane synthetase inhibitor (OKY-046) on non-heart-beating donors in orthotopic liver transplantation in rodents. OKY-046 (OKY group, n = 8) or vehicle (control group, n = 8) was given to the donor animals for 60 minutes before the induction of 30 minutes of warm ischemia to the liver before transplantation and survival, and several parameters were compared between the two groups. RESULTS: All recipients in the control group died within 2 days, whereas 67% of those of the OKY group had a 2-day survival and 44% had a 2-week survival (p < 0.01). Bile output from the allograft for 2 hours after reperfusion was significantly larger in the OKY group at all time points (p < 0.05). Furthermore, serum transaminase levels 10 minutes after reperfusion were significantly lower in the OKY group (p < 0.05), although those 120 minutes after reperfusion were comparable between the two groups. The thromboxane B2 level in liver tissue 10 and 120 minutes after reperfusion was significantly lower in the OKY group compared with the control group (p < 0.02 and p < 0.05, respectively). CONCLUSIONS: These results indicate that OKY-046 given to the donor before the induction of warm ischemia could ameliorate ischemia/reperfusion injury of the hepatic allograft by reducing thromboxane A2 production after reperfusion.

Alanine Transaminase↗
PubMed1997

Effects of estrogenic hormones on early development of Xenopus laevis.

Many chemicals released into the environment have estrogenic activity and can disrupt animal development and the function of endocrine systems. In order to study the effects of estrogens on aquatic animals, we examined the effects of certain estrogens on early development in Xenopus laevis. X. laevis embryos were kept in water containing 10(-10), 10(-9), 10(-7), 10(-6), and 10(-5) M 17 beta-estradiol (E2); 17 alpha-estradiol; diethylstilbestrol (DES); 10(-5) M progesterone (P); or dihydrotestosterone (DHT) beginning at developmental stage 3. Survival rates of the embryos developed in water containing 10(-10)-10(-6) M E2 or DES, all concentrations of 17 alpha-estradiol, and 10(-5) M P or DHT, which were over 70% after stage 48, whereas the rates of the embryos treated with 10(-5) M E2 and DES decreased remarkably after stage 27 and all embryos were dead by stages 42 and 32, respectively. Embryos treated with 10(-5) M E2 showed malformations of the head and abdomen and suppressed organogenesis, including crooked vertebrae at stage 38; the head was smaller and the abdomen was larger than in the controls. Similar effects were observed in embryos developed in 10(-5) M DES but not in 10(-5) M 17 alpha-estradiol, P, or DHT. After 10(-5) M E2 treatment, abnormalities were induced only when the treatment was started before stage 39. However, on day 30 after fertilization, the stage of the embryos treated with 10(-6) M E2 was more progressed than that of the controls. Estrogen receptor (ER 4) mRNA was examined in eggs, embryos, and adult female liver by reverse-transcription polymerase chain reaction. ER4 mRNA was expressed in adult liver, unfertilized and fertilized eggs, and embryos, but ER3 mRNA was not expressed. ER4 mRNA in 10(-6) and 10(-5) M E2-treated embryos showed different expression patterns, which may result from the diverse developmental effects of E2. The present results demonstrate that 10(-5) M E2 and DES induced embryo death and malformations and that ER may be involved in the induction of various developmental defects in X. laevis embryos.

Abdomen↗
PubMed1997

Phase Behavior of a Water/Nonionic Surfactant/Oil Ternary System in the Presence of Polymer Oil

The effect of a polymer oil, polydimethyl siloxane, on the phase behavior of the water/C12EO6/isopropyl myristate (IPM) system has been studied. Since the polymer oil is completely soluble in IPM, it was dissolved in IPM and the solutions were used as the oil phase to study its effect. The presence of polymer increases the hydrophobic nature of IPM and thereby decreases the solubilization of oil into the surfactant phase (microemulsion). Moreover, at a certain range of silicone oil concentration in the IPM, a four-phase body consisting of excess water, excess oil, and two surfactant phases is formed within the ternary system. The two surfactant phases are designated as D (with bicontinuous type of structure) and D' (with L3 type of structure). Careful phase behavioral studies revealed that, with increasing silicone oil concentration, a three-phase region containing water phase, D' phase, and an oil-rich D phase develops within the system and this region overlaps with the normal three-phase region of the system containing the water, D, and oil phases to give a four-phase body. The order of various phases from top to bottom in the four-phase body is oil, D, D', and water.

Journal Article↗
PubMed1997

Stent placement for recurrent vasospastic angina resistant to medical treatment.

The successful stent placement for treatment of recurrent vasospastic angina in a patient with nonstenotic coronary arteries is described. Use of the Palmaz-Schatz stent resulted in successful vasodilation that completely prevented anginal attacks. This procedure represents an alternative treatment for patients with vasospastic angina refractory to aggressive medical therapy.

Angina Pectoris, Variant↗
PubMed1997

Serum thrombopoietin levels in patients undergoing autologous peripheral blood stem cell transplantation.

Recently, the ligand for c-mpl has been cloned and initial studies have shown it to be the platelet regulatory factor, thrombopoietin (TPO). To elucidate the role of TPO in the reconstitution of megakaryopoiesis and platelet production after stem cell transplantation, we measured serum TPO levels in nine patients undergoing autologous peripheral blood stem cell transplantation (PBSCT) and in healthy volunteers. Serum TPO levels significantly correlated with the degree of peripheral thrombocytopenia and a strong inverse correlation between serum TPO level and platelet count was observed (r = -0.700, P < 0.001). Serum TPO levels began to rise as the platelet count decreased after chemotherapy, TPO levels peaked at over 25.00 fmoles/ml between days 0 and 10; TPO levels then decreased gradually as the platelet count began to rise. One patient with multiple myeloma received purified CD34+ peripheral blood stem cells. No difference was observed in the kinetics of serum TPO levels between unfractionated and purified PBSCT. These observations suggest that TPO plays a critical role in the reconstitution of megakaryopoiesis and platelet production after PBSCT.

Adolescent↗
PubMed1997

Distribution and localization of galectin purified from Rana catesbeiana oocytes.

Galectins are a family of lectins that recognize beta-D-galactosides independently of calcium ions, and are widely distributed in animals. To characterize a galectin previously purified from oocytes of Rana catesbeiana (American bullfrog), we studied its distribution and localization in several tissues from this frog. Hemagglutination assay and western blotting showed that this lectin is present in many tissues including the liver, skin, kidney, skeletal muscle, and sciatic nerve, but is particularly concentrated in the ovary. Light microscopic immunohistochemistry showed that this lectin is localized in such places as cell-cell junctions, basement membranes, extracellular matrix, or secretory substances in several organs, indicating that this galectin is mainly distributed extracellularly. However, in the ovary, light microscopy showed that this lectin is present in or associated with the yolk platelet. Electron microscopy further revealed that it is localized in the periphery of the yolk platelet (the yolk plasm), but not in the cortical granule. These results indicate that Rana oocytes contain abundant galectin in their yolk platelets in contrast to Xenopus laevis oocytes, which have been found not to contain galectins but other classes of lectins in their yolk platelets and cortical granules.

Amino Acid Sequence↗
PubMed1997

The soluble methane monooxygenase gene cluster of the trichloroethylene-degrading methanotroph Methylocystis sp. strain M.

In methanotrophic bacteria, methane is oxidized to methanol by the enzyme methane monooxygenase (MMO). The soluble MMO enzyme complex from Methylocystis sp. strain M also oxidizes a wide range of aliphatic and aromatic compounds, including trichloroethylene. In this study, heterologous DNA probes from the type II methanotroph Methylosinus trichosporium OB3b were used to isolate souble MMO (sMMO) genes from the type II methanotroph Methylocystis sp. strain M. sMMO genes from strain M are clustered on the chromosome and show a high degree of identity with the corresponding genes from Methylosinus trichosporium OB3b. Sequencing and phylogenetic analysis of the 16S rRNA gene from Methylocystis sp. strain M have confirmed that it is most closely related to the type II methanotroph Methylocystis parvus OBBP, which, unlike Methylocystis sp. strain M, does not possess an sMMO. A similar phylogenetic analysis using the pmoA gene, which encodes the 27-kDa polypeptide of the particulate MMO, also places Methylocystis sp. strain M firmly in the genus Methylocystis. This is the first report of isolation and characterization of methane oxidation genes from methanotrophs of the genus Methylocystis.

Amino Acid Sequence↗
PubMed1997

Characteristics of Escherichia coli HB101 and Pseudomonas putida PpY101 harboring a recombinant plasmid with tandem insertion of the mercury resistance operon.

We constructed the plasmid pSUPmer2 by inserting tandem copies of the mercury resistance (mer) operon into a broad host range-vector, and introduced it into Escherichia coli HB101 and Pseudomonas putida PpY101 to increase their mercury resistance. Strains harboring plasmid pSUPmer2 had higher mercury resistance and mercuric reductase activity than those strains harboring the plasmid pSUPmer which had one copy of the mer operon. Mercury resistance of P. putida PpY101 was significantly increased by tandem insertion of the mer operon.

Cell Division↗
PubMed1997

Fusion with postpaced return cycle identical to tachycardia cycle length during transient entrainment of ventricular tachycardia and its implications.

In reentrant ventricular tachycardia (VT), the postpaced return cycle (RC) during transient entrainment at a pacing site far from the central common pathway is longer than the VT cycle length (VTCL), when VT is represented by a figure-eight model. However, the reentrant circuit has not been fully elucidated. The purpose of this study was to present VT in which the postpaced RC became identical to VTCL during transient entrainment while fusion is evident in the surface electrocardiogram (ECG). Among 38 patients with inducible reentrant VTs who underwent electrophysiologic study (EPS), 10 VTs of six patients were selected. All patients had underlying heart diseases: dilated cardiomyopathy (n = 2), coronary artery disease (n = 1), postoperative tetralogy of Fallot (TOF; n = 2), and arrhythmogenic right ventricular dysplasia (n = 1). Catheter mapping was performed to demonstrate that the site of origin was distant from the pacing site. The cycle length of induced VT (n = 10 VTs) was 380 +/- 41 msec. Five patients (83%) had two morphological VTs; one a left bundle branch block (LBBB) and the other a right bundle branch block (RBBB) pattern. During rapid pacing, constant fusion was observed in all VTs, but the postpaced RC was identical to VTCL. In 2 patients (4 VTs), the revolution of wavefronts around an anatomical obstacle (scar of myotomy in TOF, and infarction) was demonstrated. The fact that the postpaced RC was identical to VTCL but showed fusion in the surface ECG can be explained by macro-reentry. The pacing site must be located at the preferential route of the macroreentrant circuit.

Adolescent↗
PubMed1997

Effectiveness of aldose reductase inhibitors for diabetic gastroenteropathy with constipation.

We present a diabetic patient with long-standing constipation complicated by paralytic ileus and septic shock. She successfully recovered from a critical condition, and her diabetes was well controlled. However, the constipation did not improve even after the administration of conventional medications. Epalrestat, an aldose reductase inhibitor (ARI), improved her bowel motility and autonomic cardiovascular dysfunction, as evident from her heart rate and blood pressure response. Gastroenteropathy is a major diabetic complication which may cause disturbed bowel motility leading to serious enterobacterial infections, thus, its amelioration is important. ARI may be beneficial in the treatment of diabetic gastroenteropathy refractory to conventional therapies.

Aldehyde Reductase↗
PubMed1997

[Basilar artery aneurysm associated with agenesis of unilateral internal carotid artery: two case reports].

Two patients presented with a basilar artery aneurysm associated with agenesis of the right internal carotid artery. In both cases, the right middle cerebral artery was supplied by the basilar artery via the enlarged right posterior communicating artery, and the right anterior cerebral artery was supplied by the left internal carotid artery via the anterior communicating artery. The first patient was a 65-year-old woman who suffered from a subarachnoid hemorrhage due to rupture of a basilar bifurcation aneurysm, which was demonstrated as a "de novo" aneurysm 13 years after successful clipping of the anterior communicating artery aneurysm. Delayed surgery was planned, but she died due to recurrent hemorrhage. The second patient was a 67-year-old woman who had had a history of progressive left sided weakness over the previous few years. Conventional angiography and 3 dimensional CT angiography showed a large aneurysm of the basilar artery trunk with a wide neck. Endovascular embolization was performed with mechanically detachable coils, and the aneurysm was incompletely occluded. The patient regained complete strength in the left arm after the treatment, but the follow-up angiography at 5 months disclosed recanalization of the treated aneurysm, associated with shift of the packed coils. Hemodynamic stress resulting from unique collateral circulation with agenesis of the internal carotid artery may cause a predisposition to "de novo" aneurysm formation or recanalization of an occluded aneurysm with coils.

Aged↗
PubMed1997

Detection of hepatitis C virus RNA in bile.

OBJECTIVES: The infectivity of bile in patients with hepatitis C virus (HCV) infection remains to be clarified. The purpose of this study was to document the detection of HCV-RNA in bile of patients with HCV infection. METHODS: Bile and serum samples were tested for HCV RNA by a two-step polymerase chain reaction technique in 12 patients with HCV infection. RESULTS: HCV-RNA was detected in the serum of all 12 patients, whereas 6 of 12 bile samples (50%) tested positive. Comparison of laboratory data between patients with and without HCV-RNA in bile demonstrated statistically higher serum total bilirubin among those with positive bile HCV RNA than those without, but other clinical and biochemical variables as well as hepatitis activity scores were comparable between the two groups. CONCLUSIONS: Bile of HCV antibody-positive patients could be infectious.

Aged↗
PubMed1997

[Survival of Vibrio cholerae non-O1 in freshwater river].

The survival of Vibrio cholerae non-O1 was investigated in sterile and untreated river water. The essential nutrients for growth of the organism were also investigated using a compound medium. V. cholerae non-O1 was shown to increase in autoclaved sterile river water, but did not increase in filtrated river water, and starting with an initial number of 10(6) CFU/ml organism, the organism could not be isolated from untreated river water after day 10. The growth or survival of the organism was also studied with filtrated river water to which all essential nutrients except one was added. In this water, V. cholerae non-O1 did not increase when either phosphate or a carbon source was not present. These results indicate that V. cholerae non-O1 can survive in river water by taking nutrients for growth from solutes and particle matter in the river water.

Ammonia↗
PubMed1996

Migration of GnRH-immunoreactive neurons from the olfactory placode to the brain: a study using avian embryonic chimeras.

Previous studies suggest that gonadotropin-releasing hormone (GnRH) neurons appear in the olfactory placode and subsequently migrate into the brain during embryonic development. The aim of the present study was to obtain direct evidence for migration of GnRH neurons from the olfactory placode into the brain. Olfactory placodes from quail embryos were transplanted isotopically and isochronically, to replace the unilaterally ablated olfactory placodes of chick embryos. The chimeric embryos were allowed to develop for several days until they reached the embryonic stages when GnRH neurons are seen in the brain in normal embryos. Quail olfactory epithelia were formed in the host chick embryos. Quail olfactory nerves were also formed and reached the olfactory bulb or primordial olfactory bulb. GnRH-immunoreactive cells of quail origin revealed by a triple staining method were observed in the quail olfactory epithelium, quail olfactory nerve, chick olfactory bulb, and septo-preoptic area. These results indicate that GnRH neurons originate in the olfactory placode and migrate into the telencephalon including the septo-preoptic area. A migratory route of GnRH neurons was well documented by the use of a quail neuron-specific antibody, QN. The migratory route in the brain is discussed with special reference to the terminal nerve. A GnRH-immunoreactive neuronal group of chick origin appeared in the diencephalon of chimeric embryos. These diencephalic neurons may be of non-placodal origin. FMRFamide-immunoreactive neurons of quail origin were also found in the quail olfactory nerve and the host olfactory bulb, suggesting that FMRFamide neurons also originate in the olfactory placode and migrate into the brain.

Animals↗
PubMed1996

Phosphorylation of human m1 muscarinic acetylcholine receptors by G protein-coupled receptor kinase 2 and protein kinase C.

Human muscarinic acetylcholine receptor m1 subtypes (m1 receptors) were expressed in and purified from insect Sf9 cells and then subjected to phosphorylation by G protein-coupled receptor kinase 2 (GRK2) expressed in and purified from Sf9 cells and by protein kinase C purified from rat brain (a mixture of alpha, beta, and gamma types, PKC). The m1 receptor was phosphorylated by either GRK2 or PKC in an agonist-dependent or independent manner, respectively. G protein beta gamma subunits stimulated the phosphorylation by GRK2 but did not affect the phosphorylation by PKC. The number of incorporated phosphates was 4.6 and 2.8 mol/mol of receptor for phoshorylation by GRK2 and PKC, respectively. The number of incorporated phosphates was 7.5 mol/mol receptor for phosphorylation by GRK2 followed by PKC, but was 5.8 mol/mol of receptor for the phosphorylation by PKC followed by GRK2. Major sites phosphorylated by GRK2 and PKC were located in the third intracellular loop and the carboxyl-terminal tail, respectively. These results indicate that GRK2 and PKC phosphorylate different sites of m1 receptors and that the phosphorylation by PKC partially inhibits the phosphorylation by GRK2, probably by affecting activation of GRK2 by agonist-bound receptors.

Amino Acid Sequence↗