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Biomedical subjects

M Nishikawa

Publications and source records attributed to M Nishikawa.

At least 487 records · Page 27Linked to original sources
PubMed1993

Spa bathing activates fibrinolysis in patients with cerebral infarction.

The effects of spa bathing on blood coagulation and fibrinolysis were studied in 20 patients with chronic cerebral infarction. Blood was obtained before and after a 10-minute period of spa bathing at 41 degrees C. Prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIII activity, von Willebrand factor activity, and antithrombin III activity did not show significant changes after bathing, but euglobulin lysis time was significantly reduced (p < 0.01) and fibrin lysis activity was increased (p < 0.05). These findings suggest that spa bathing activates fibrinolysis without markedly changing blood coagulation in patients with chronic cerebral infarction. It is thought that the activation of fibrinolysis without the activation of coagulation has a favorable effect on blood circulation. The results of fibrin-plate assays using C1 inactivator indicated that tissue-type plasminogen activator was the major contributor to the activation of fibrinolysis during spa bathing.

Aged↗
PubMed1993

[Inhibitory effect of prior panretinal photocoagulation on experimental iris neovascularization].

We could produce iris neovascularization experimentally in rhesus monkey eyes, by occlusion of the major retinal vessels of the retina and persistent ocular hypotony. We confirmed that panretinal photocoagulation inhibits development of iris neovascularization. We evaluated the effect of panretinal photocoagulation one month before occlusion of major retinal vessels with secondary iris neovascularization in 3 monkey eyes. Rubeosis iridis appeared on day 5 and disappeared on day 14 after retinal vessel occlusion. Histologically, the newly formed vessels near the iris surface showed fenestrations and protruded into the anterior chamber. The endothelial cells were flat and similar to matured vessels. These findings were in sharp contrast to our previous experiments with panretinal photocoagulation after rubeosis iridis became manifest. The findings also showed that retinal scarring by preceding panretinal photocoagulation did not completely inhibit the iris neovascularization.

Animals↗
PubMed1993

Characterization of guinea pig pulmonary neurokinin type 1 receptors using a novel antagonist ligand, [3H]FK888.

We have characterized the binding of a novel radioligand, [3H] FK888, to neurokinin (NK)1 receptors in guinea pig lung membranes and localized its binding in guinea pig lung sections by autoradiography. Lung membranes were incubated with [3H] FK888 at 25 degrees and the assays were terminated by rapid filtration; nonspecific binding was defined as binding in the presence of 1 microM concentrations of the nonpeptide NK1-selective antagonist CP-96,345. Kinetic analysis showed that specific binding of [3H] FK888 (approximately 70% of total binding) was rapid, reaching a plateau by 20 min, and that binding was reversed by addition of 1 microM CP-96,345, giving a kinetic Kd of 0.46 nM. Binding of [3H] FK888 was saturable at approximately 1 nM, and equilibrium binding analysis gave a Kd of 0.32 +/- 0.03 nM and a Bmax of 46.9 +/- 7.1 fmol/mg of protein (four experiments). In competition studies, substance P, CP-96,345, and FK888 competed for [3H] FK888 binding, but NKA, NKB, and NK2-selective antagonists such as SR48968 and L-659,877 did not. Guanosine-5'-O-(3-thio)triphosphate significantly shifted the competition curve for substance P competition against [3H]FK888 binding to a lower affinity state, confirming that NK1 receptors are coupled to a G protein. Autoradiographic mapping in cryostat sections of lung showed that [3H]FK888 binding was dense over smooth muscle of all airways, with moderate binding over epithelium of bronchi and bronchioles as well as submucosal glands of trachea. No significant labeling of blood vessels was observed. [3H]FK888 binds to NK1 receptors in guinea pig lung and may be a useful tool for studying the expression and regulation of NK1 receptors.

Animals↗
PubMed1993

[The effect of corticosteroid on the repair of the retinal pigment epithelium].

The effect of corticosteroid on the repairing process of the retinal pigment epithelial cells (RPE) after laser photocoagulation was investigated. Mild-intensity krypton red laser photocoagulations were performed on the monkey retina. After laser photocoagulations, betamethasone (0.5 mg/kg) were administered intramuscularly every day for 1-14 days. Moreover, the same doses of betamethasone were also administered intramuscularly for one week from the 1st to 7th day after laser photocoagulation on other monkeys. The photocoagulated lesions were observed with light and transmission electron microscopy. In monkeys that received corticosteroids, the migration and the proliferation of RPE were markedly inhibited, and the metaplasia to fibroblast-like cells of RPE was not observed. These results showed that large doses of corticosteroid inhibited the repair process of the injured RPE.

Animals↗
PubMed1993

Ultrastructural localization of 5'AMP odorant receptor sites on the dendrites of olfactory receptor neurons of the spiny lobster.

A unique probe--biotinylated adenosine-5'-monophosphate (5'AMP-biotin)--was used in transmission electron microscopic (TEM) studies to localize 5'AMP odorant binding sites on the dendrites of olfactory receptor neurons in the aesthetasc sensilla of the spiny lobster, Panulirus argus. This probe is capable of both binding to and exciting 5'AMP-sensitive olfactory receptor neurons, as revealed through biochemical and electrophysiological assays. TEM studies showed that 5'AMP-biotin binding sites are distributed along the entire dendritic region that is exposed to odorants, including the transitional zone (between the inner and outer dendritic segments, including the ciliary segment) and all of the outer dendritic segment. The density of 5'AMP binding sites per micron2 of membrane is similar along the length of the olfactory dendrite. However, the relative number of 5'AMP-biotin binding sites per micron2 of sensillar area diminishes in the distal 30% of the aesthetasc due to a decrease in the amount of dendritic membrane in that region. The distribution of these 5'AMP binding sites is therefore much more extensive than that of enzymes that inactivate 5'AMP--5'ectonucleotidase/phosphatase--which are restricted to the transitional zone (Gleeson et al., 1991). Taken together, these results suggest that 5'AMP-biotin is labeling 5'AMP-specific olfactory receptor sites that are located along the entire outer dendritic segment and that can be coupled to olfactory transduction. This study represents the first in situ localization of specific olfactory receptor sites using a specific, functionally defined ligand.

Adenosine Monophosphate↗
PubMed1993

[A midbrain arteriovenous malformation at quadrigeminal plate completely obliterated by embolization].

An eighteen year-old boy presented sudden loss of consciousness and tetraparesis. Radiological examinations revealed a ruptured midbrain arteriovenous malformation (AVM) at the right quadrigeminal plate. The patient recovered from symptoms by conservative treatment over 6 months with residual right hemisensory disturbance and mild diplopia during bilateral horizontal gaze. One year later, he was admitted to our institute for radical treatment of the AVM. On the angiography, the AVM was fed by two branches of the right long circumferential artery and a left paramedian penetrating artery of the posterior cerebral artery (PCA), and drained into the straight sinus via a dilated quadrigeminal vein. After much discussion on several strategies, endovascular surgery was chosen as a radical treatment. In the initial session, a medial branch of the right long circumferential artery was catheterized with Tracker-18, and embolized with 1.0 ml of ethylene vinyl alcohol copolymer (EVAL) without any deficits after negative provocative tests using Amytal and Xylocaine. Then, a lateral branch of the same artery was embolized with 0.8 ml of EVAL in the same way without any deficits. In the second session, catheterization into the left paramedian artery was difficult because of its small diameter and steep branching angle, and only a 3 mm hooked tip of Tracker-18 could be canulated into the feeding pedicle. Left oculomotor palsy was induced by provocative Xylocaine test. However, angiographic cure of the AVM was expected to be made possible by the occlusion of this pedicle, and the procedure was continued due to the request of the patient and his family.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

A Paneth cell specific zinc-binding protein in the rat. Purification and immunohistochemical localization.

BACKGROUND: Paneth cells are zinc-containing cells widely distributed in Lieberkühn's crypts of small intestine in many species, but their function has remained obscure. Our previous study showed that a single intravenous injection of diphenylthiocarbazone (dithizone), a zinc chelator, forms zinc-dithizonate complexes in the cytoplasm of Paneth cells to ensure rapid and selective killing of the cells. EXPERIMENTAL DESIGN: To verify the proteins that selectively deleted from intestinal mucosa after dithizone treatment, intestinal proteins from the rats with or without dithizone injection were compared in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. One such protein, a 90 kilodalton (kd) protein, was purified to homogeneity from normal rat intestine. A polyclonal antiserum was prepared by immunizing a rabbit with purified 90 kd protein to use in immunohistochemical study. RESULTS: Among several proteins deleted after dithizone injection, a 90 kd protein with an isoelectric point of 5.9 +/- 0.2, was purified to homogeneity from normal intestine by a combination of zinc affinity column and electroelution. Immunohistochemistry with rabbit anti-90 kd antiserum showed that the cytoplasmic granules in Paneth cells were stained. After dithizone administration, the 90 kd protein containing cells rapidly disappeared, but resumed as Paneth cells regenerated. Also positively stained with this antibody were a few mononuclear cells broadly distributed in the lamina propria of the digestive tract, but they were not affected by dithizone treatment. CONCLUSIONS: A 90 kd zinc-binding protein was identified and purified from rat Paneth cells that was deleted in dithizone-treated rat intestine. We propose to designate it as a zinc-binding protein of Paneth cell.

Animals↗
PubMed1993

[Fibromuscular dysplasia with an internal carotid artery web on the angiograms].

A 58-year-old woman experienced a transient right-sided hemianopsia. She also had difficulty finding words and trouble naming parts of objects. On admission, three days later, there were no signs of residual neurological deficit. Laboratory studies showed findings of neither diabetes mellitus, hypertension nor cardiac disease. Her serum cholesterol level was normal. No bruit was heard over the head and neck. Preoperative angiograms showed a discrete web (septum) at the left internal carotid origin (Fig. 2). 123I-IMP SPECT revealed a decreased areas of perfusion mainly in the left middle cerebral artery distribution (Fig. 3A). A reconstructive operation was performed. A firm discrete nonatherosclerotic ridge (septum) protruding into the vessel lumen was resected. Microscopic examination of the surgical specimen demonstrated intimal fibroplasia, a rare subtype of fibromuscular dysplasia (FMD). Postoperatively, hypoperfused areas in SPECT were improved (Fig. 3B). The patient has been free of symptoms to the present time (for about one year). In addition to the rarity of the lesion, the available data suggest that web-like subtype of FMD is apt to be associated with an increase in the risk of hemodynamic compromise and thromboembolism. Surgical therapy is recommended, especially for symptomatic patients.

Carotid Artery, Internal↗
PubMed1993

Effect of cholecystokinin on food intake at different stages of the estrous cycle in female rats.

Effects of cholecystokinin octapeptide (CCK-8) on feeding behavior were examined in male and female rats. After an 18-hour fast, ad lib food intake for 30 minutes was measured for each rat. In male rats, food intake measured for 30 minutes was significantly decreased by intraperitoneal injection of 0.25 to 1 microgram/kg of CCK-8 in a dose-dependent manner. The satiety effect of CCK-8 was blocked by L-364,718 (20 nmol/kg), a specific cholecystokinin receptor antagonist. In female rats, food intake at proestrus and estrus was significantly less than that at diestrus. Food intake of female rats at diestrus and metestrus was significantly decreased by an intraperitoneal injection of CCK-8 prior to feeding, but it was not affected at proestrus and estrus. The effect of CCK-8 on food intake at diestrus and metestrus was dose dependent and was nearly abolished when 20 nmol/kg of L-364,718 was administered simultaneously. The results of this study suggest that stages of the estrous cycle affect feeding behavior of rats. Further, cholecystokinin's regulatory action on feeding behavior appears to be effective at diestrus and metestrus, but not at proestrus and estrus.

Animals↗
PubMed1992

Augmentation of retinoic acid-induced granulocytic differentiation in HL-60 leukemia cells by serine/threonine protein phosphatase inhibitors.

To evaluate the involvement of protein phosphatases (PP) in differentiation of human myelogenous leukemia HL-60 cells, we made use of potent inhibitors of PP1 and PP2A, calyculin-A (CAL-A) and okadaic acid (OKA). CAL-A and OKA could augment all-trans retinoic acid (ATRA)-induced granulocytic differentiation, whereas the differentiation toward macrophage lineage by 12-o-tetradecanoylphorbol acetate (TPA) was unchanged in the presence of CAL-A. CAL-A augmented the phosphorylation of 18K, 23K and 30K proteins induced by ATRA. The PP1 and PP2A were identified and were present mainly in the cytosol of HL-60 cells. These results suggest that either PP1 or PP2A or both may be involved in regulating granulocytic differentiation of HL-60 cells.

Cell Adhesion↗
PubMed1992

Therapeutic effects of superoxide dismutase derivatives modified with mono- or polysaccharides on hepatic injury induced by ischemia/reperfusion.

Therapeutic effects of four types of recombinant superoxide dismutase (SOD) derivatives, conjugates with polysaccharides, carboxymethyl (SOD-CMD) and diethylaminoethyl (SOD-DEAED) dextrans and galactosylated (Gal-SOD) and mannosylated (Man-SOD) derivatives, on hepatic ischemia/reperfusion injury were studied in rats. Hepatic injury induced by transient occlusion and subsequent reflow of hepatic blood was evaluated by the analysis of biliary excretion of bromosulfophthalein (BSP) injected intravenously. At a dose of 10000 units/kg, native SOD and SOD-DEAE did not show any significant effect and SOD-CMD showed slight effect. On the other hand, Gal-SOD and Man-SOD, targeted to the liver parenchymal and nonparenchymal cells, respectively, by a receptor-mediated endocytosis, exhibited superior inhibitory effects. These results demonstrated that these glycosylated SOD derivatives were useful for the prevention of hepatic ischemia/reperfusion injury.

Animals↗
PubMed1992

Deletion mutagenesis of stem cell factor defines the C-terminal sequences essential for its biological activity.

We constructed a series of murine stem cell factor (mSCF) cDNAs which were sequentially truncated at the 3' termini. The resultant six mutant cDNA encode N-terminal 183, 179, 162, 149, 142 and 133 amino acid residues of the mature mSCF protein fused to the heterogeneous C-terminal peptides derived from the linker sequences. Each mutant cDNA was transiently expressed in COS cells, and the cultured supernatant was assayed for its ability to support the growth of a human factor-dependent cell line, TF-1 and to enhance colony formation by murine hematopoietic progenitor cells. The results showed that as few as N-terminal 142 but not 133 amino acid residues of mSCF remained biologically active in vitro, suggesting that the region of 9 amino acids from Asp134 to Ser142 containing a Cys138-mediated disulfide bond may contribute to the C-terminal end of the active subdomain of mSCF.

Amino Acid Sequence↗
PubMed1992

AE0047, a new dihydropyridine Ca2+ entry blocker, inhibits the responses to adrenergic nerve stimulation and substance P in dog mesenteric arteries.

AE0047, a new dihydropyridine-type Ca2+ entry blocker, significantly inhibited the contractions induced by transmural electrical stimulation and norepinephrine in dog mesenteric artery strips. The inhibition was greater in the case of the response to nerve stimulation. The 3H-overflow ratio evoked by electrical stimulation from strips previously soaked in [3H]norepinephrine was significantly reduced by AE0047 but not by nicardipine in a concentration sufficient to attenuate the response to norepinephrine. In aorta homogenate preparations, [3H]bunazosin binding was not replaced by AE0047 but by phentolamine. In strips treated with indomethacin, the endothelium-dependent relaxation caused by substance P and bradykinin was attenuated by treatment with AE0047 but not with nicardipine. The nitric oxide (NO)-induced relaxation was not influenced by AE0047. Cyclic GMP levels in the artery strips increased in response to substance P; the increase was markedly suppressed by AE0047 but not by nicardipine. In contrast to nicardipine, AE0047 appeared to inhibit the release of norepinephrine from adrenergic nerves and of NO from endothelial cells. The inhibition may be associated with the decreased transmembrane influx of Ca2+ in these tissues.

Adrenergic alpha-Agonists↗
PubMed1992

High-performance liquid chromatographic determination of pamaquine, primaquine and carboxy primaquine in calf plasma using electrochemical detection.

A high-performance liquid chromatographic method with electrochemical detection is described for quantification of pamaquine, primaquine and carboxy primaquine in calf plasma. After the proteins had been precipitated with acetonitrile, the drugs were separated on a 5-microns C18-modified polymer gel column with an isocratic mobile phase. The detection limit was 0.01 microgram/ml in plasma for all three compounds. The applicability of the method in pharmacokinetic studies was demonstrated by determining the plasma concentrations of the three substances in calves administered a single dose of pamaquine or primaquine.

Aminoquinolines↗
PubMed1992

Partial purification of phosphoramidon-sensitive endothelin converting enzyme in porcine aortic endothelial cells: high affinity for Ricinus communis agglutinin.

A membrane-bound endothelin converting enzyme (ECE) of porcine aortic endothelial cells (ECs) was solubilized with Lubrol PX with high efficiency and stability. The solubilized ECE was bound to Ricinus communis agglutinin (RCA) but not to peanut agglutinin (PNA) or wheat germ agglutinin (WGA), suggesting that the ECE has a galactosylated structure possessing a high affinity for RCA. The sequential chromatography on RCA-agarose, PNA-agarose and a TSKgel DEAE-5PW column attained 2,100-fold purification for the ECE over the membrane fractions. The purified ECE was sensitively inhibited by phosphoramidon but not by thiorphan. The present RCA and PNA affinity column procedures may be a powerful approach to isolation of ECE of EC origin.

Animals↗