Prolonged weakness after long-term infusion of vecuronium bromide.
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Adolescent↗
Biomedical subjects
T Namba
Publications and source records attributed to T Namba.
Mouse thromboxane A2 receptor: cDNA cloning, expression and northern blot analysis.
A cDNA clone for the mouse thromboxane A2 receptor was isolated from mouse lung cDNA library. The cDNA has a 1,023 base pair open reading frame which encodes a protein of 341 amino acid residues. STA2 and U-46619 induced inward current in Xenopus laevis oocytes injected with the transcript of the clone. Specific binding of [3H]S-145 was found in membranes of COS-1 cells transfected with the cDNA (Kd = 3.3 nM) and was displaced with unlabeled prostaglandins and thromboxane analogues in the order of S-145 greater than STA2 greater than U-46619 greater than PGD2 greater than PGF2 alpha = PGE2. Northern blot analysis demonstrated that thromboxane A2 receptor mRNA is expressed abundantly in thymus, spleen and lung.
Amino Acid Sequence↗
Cloning and expression of a cDNA for mouse prostaglandin E receptor EP3 subtype.
A functional cDNA clone for mouse EP3 subtype of prostaglandin (PG) E receptor was isolated from a mouse cDNA library using polymerase chain reaction based on the sequence of the human thromboxane A2 receptor and cross-hybridization screening. The mouse EP3 receptor consists of 365 amino acid residues with putative seven-transmembrane domains. The sequence revealed significant homology to the human thromboxane A2 receptor. Ligand binding studies using membranes of COS cells transfected with the cDNA revealed specific [3H]PGE2 binding. The binding was displaced with unlabeled PGs in the order of PGE2 = PGE1 greater than iloprost greater than PGF2 alpha greater than PGD2. The EP3-selective agonists, M&B 28,767 or GR 63799X, potently competed for the [3H]PGE2 binding, but no competition was found with EP1- or EP2-selective ligands. PGE2 and M&B 28,767 decreased forskolin-induced cAMP formation in a concentration-dependent manner in Chinese hamster ovary cells permanently expressing the cDNA. Northern blot analysis demonstrated that the EP3 mRNA is expressed abundantly in kidney, uterus, and mastocytoma P-815 cells and in a lesser amount in brain, thymus, lung, heart, stomach, and spleen.
Alprostadil↗
Effects of strychnine-insensitive glycine receptor antagonist (7-chlorokynurenic acid) on amygdala kindling in rats.
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Amygdala↗
Development of natural crude drug resources from Taiwan (X). Pharmacognostical studies on the Chinese crude drug "han-lian-cao".
In a previous paper(1), it was reported that the drug "Han-lian-cao", in Taiwan was derived from the entire plant or aerial part of Eclipta prostrata L. and Alternanthera sessilis R. Brown. In this paper, the histological studies of "Han-lian-cao" derived from Wedelia and Hypericum plants, and of 3 species of Wedelia related plants distributed in Taiwan were made. The results showed that it was possible to classify these species by their external and internal characteristics. In addition, a key to the characteristics of the whole plants of Eclipta, Alternanthera, Wedelia and Hypericum plants are hereby given.
Botany↗
Inhibitory effects of glycyrrhetic acid and its related compounds on 3 alpha-hydroxysteroid dehydrogenase of rat liver cytosol.
Glycyrrhetic acid (GA), aglycone of glycyrrhizin (GL), inhibited potently (I50 = 7 x 10(-6) M) and non-competitively the activity of NAD(P)+-linked 3 alpha-hydroxysteroid dehydrogenase of rat liver cytosol. The inhibition was slightly weaker than that of indomethacin, a potent anti-inflammatory agent, but stronger than that of dexamethasone, another anti-inflammatory agent. GL, GA monoglucuronide, and 3-epi-glycyrrhetic acid also inhibited this enzyme activity, but did so less effectively (I50 = 5-8 x 10(-5) M). Carbenoxolone (GA 3-hemisuccinate) and 3-keto-glycyrrhetic acid showed potent inhibitory effects similar to GA, and 18 alpha-GA showed the most powerful inhibition of the activity.
3-Hydroxysteroid Dehydrogenases↗
Isolation of novel lignans, heteroclitins F and G, from the stems of Kadsura heteroclita, and anti-lipid peroxidative actions of heteroclitins A-G and related compounds in the in vitro rat liver homogenate system.
From the stems of Kadsura heteroclita, two new lignans named heteroclitins F and G were isolated and their structures were determined by various spectroscopic means including an X-ray diffraction method. Dibenzocyclooctadiene type lignans and related compounds isolated from the stems of K. heteroclita, potently inhibited the lipid peroxidation in the rat liver homogenate stimulated by Fe(2+)-ascorbic acid, CCl4-reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine 5'-diphosphate-NADPH.
Animals↗
Constituents of the roots of Cynanchum bungei Decne. Isolation and structures of four new glucosides, bungeiside-A, -B, -C, and -D.
Four new glucosides, bungeiside-A, -B, -C, and -D, were isolated from the roots of Cynanchum bungei Decne. The structures of the new compounds were determined by chemical and spectroscopic methods, including two-dimensional nuclear magnetic resonance (2D NMR) techniques, especially 1H-detected heteronuclear multiple-bond multiple-quantum coherence.
Acetophenones↗
Tinctormine, a novel Ca2+ antagonist N-containing quinochalcone C-glycoside from Carthamus tinctorius L.
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Animals↗
Anti-lipid peroxidative effect of an extract of the stems of Kadsura heteroclita and its major constituent, kadsurin, in mice.
Three-days successive p.o. administration of an EtOH extract of the stems of Kadsura heteroclita (Schizandraceae) or its major constituent, kadsurin, resulted in significant decreases of CCl4-induced lipid-peroxidation products, such as thiobarbituric acid reactive substances (TBA-RS), conjugated dienes and fluorescent products in the liver of mice. In contrast, a significant restoration of superoxide dismutase (SOD) activity reduced by CCl4-intoxication was observed in the administered groups, suggesting that the subchronic treatment of mice with the EtOH extract or kadsurin induce enzymes capable of scavenging oxygen radical species in the liver, though the extract and kadsurin themselves may have an anti-oxidant property.
Animals↗
[Studies on the baths with crude drug: the effects of Senkyu extract as skin penetration enhancer].
The effects of Senkyu (Cnidii Rhizoma and Ligustici chuanxiong Rhizoma) on the drug skin penetration were studied to clarify its effectivity as the baths. Ether and methanol extracts, and some essential oils of Senkyu (i.e. ligustilide, neocnidilide and butylidenephthalide) enhanced remarkably the skin penetration of benzoic acid. Furthermore, an appreciable correlation between the enhancing ratio and the skin/donor partition coefficient of benzoic acid was observed. These facts suggest that the constituents of Senkyu influence the skin penetration by enhancing the partition coefficient.
Animals↗
Antibodies against myofibrillar proteins in myasthenia gravis patients.
Antibodies against various myofibrillar proteins were measured by enzyme-linked immunosorbent assay (ELISA) in sera of thirty-one myasthenic patients. The antibody activity expressed as optical absorbance values was higher in 15 (48%) patients for myosin, 10 (32%) patients for tropomyosin, 9 (29%) patients for troponin, 7 (23%) patients for alpha-actinin, and 1 (3%) patient for actin as compared with 95% tolerance limits of eleven normal individuals. Twenty-five (81%) of the patients had one of these antibodies or more. Anti-myosin antibody titer was higher in male patients (0.447 +/- 0.196; mean +/- SD, p less than 0.05) than in female patients (0.316 +/- 0.107), and positively correlated with the age of onset of myasthenia gravis (r = 0.41, p less than 0.05). Anti-tropomyosin antibody titers had an inverse correlation with the age of onset (r = -0.46, p less than 0.01). No significant correlation was found between the antibody activities and other clinical conditions, including the severity and duration of disease, and treatments (systemic treatment with corticosteroids or previous thymectomy). Positive correlations were observed between anti-myosin antibody and anti-troponin antibody titers (r = 0.44, p less than 0.02), and between anti-actin antibody and anti-alpha-actin in antibody titers (r = 0.39, p less than 0.05), but no significant correlation between other pairs of antibodies against myofibrillar proteins was found.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Clostridium botulinum C3 ADP-ribosyltransferase gene. Cloning, sequencing, and expression of a functional protein in Escherichia coli.
C3 ADP-ribosyltransferase is an exoenzyme produced by certain strains of Clostridium botulinum types C and D, which specifically ADP-ribosylates rho and rac proteins in eukaryotic cells. The enzyme was purified from a culture filtrate of C. botulinum type C strain 003-9, and the amino acid sequence from the amino-terminal Ser to Asn192 was determined by Edman degradation. Using a set of degenerate primers based on the sequence, we amplified a part of the gene for this enzyme by polymerase chain reaction. A 2.1-kilobase pair HincII fragment of C. botulinum DNA containing the whole structural gene was then identified by Southern analysis with the polymerase chain reaction product as a probe, and the complete nucleotide structure of the gene together with flanking regions was determined by cloning and DNA sequencing the HincII fragment. The gene encodes a protein of 244 amino acids with a Mr of 27,362 which begins with a putative signal peptide of 40 amino acids. Escherichia coli carrying this gene produced the active enzyme, and about 60% of it was found in the culture medium. Immunoblot analysis with antiserum against the enzyme revealed the presence of two immunoreactive proteins of 27 and 23 kDa in the cytoplasmic/membrane fraction and only the 23-kDa protein in the periplasm and the medium, suggesting that the enzyme expressed is processed in the E. coli, exported into the periplasm and released into the culture medium.
ADP Ribose Transferases↗
Volcanic production of polyphosphates and its relevance to prebiotic evolution.
Phosphates would probably have been essential compounds for prebiotic evolution on the primitive Earth. In this context, there have been several studies of condensation of water-soluble phosphates to polyphosphates and phosphorylation and condensation or polymerization of biomolecules with polyphosphates. But most of the phosphorus on the early Earth would have been in the form of water-insoluble apatite, and the origin of the water-soluble polyphosphates required for prebiotic evolution has therefore been a mystery. Here we show, both from experiments that simulate magmatic conditions and from analysis of volatile condensates in volcanic gas, that volcanic activity can produce water-soluble polyphosphates through partial hydrolysis of P4O10. This mechanism seems to be the only viable route identified so far for the production of these species on the primitive Earth.
Calcium Phosphates↗
Effect of cocaine on responses of mouse phrenic nerve-diaphragm preparation.
Effects of 5 to 40 microM cocaine on the compound action potential (AP) and tension responses of the mouse phrenic nerve-diaphragm preparation were monitored following nerve and muscle stimulation at 37 degrees C. Cocaine caused concentration dependent reduction in amplitude of the nerve AP, muscle AP, and tension response to a single nerve stimulus, and greater reduction in amplitude of these responses to repetitive nerve stimuli at 100 Hz for 0.5 sec. Cocaine caused similar reduction in the muscle AP and tension responses to direct muscle stimulation in the presence or absence of curare, and markedly reduced the overshoot, total potential, and maximum rate of rise and fall of intracellularly recorded muscle AP, without affecting the resting potential, or the contracture responses evoked by caffeine. These results indicate that cocaine reduces skeletal muscle function by reducing the excitability of muscle and nerve membranes, without significantly affecting neuromuscular transmission, excitation-contraction coupling or contractility.
Action Potentials↗
Peripheral mechanisms of fatigue in muscles of normal and dystrophic mice.
We evaluated the contribution of different processes to fatigue of normal and dystrophic mouse muscles using an in vitro electromyography chamber. Fatigue was induced by repetitive nerve stimulation at 30 Hz for 0.5 s, every 2.5 s until tension decreased by about 50%. We monitored the compound nerve action potential (AP), compound muscle AP, and isometric tension responses to nerve stimulation, and compound muscle AP and tension responses to direct muscle stimulation. In normal mice, about 50% reduction in nerve-evoked tension occurred by 2.4 min in extensor digitorum longus (EDL), 4.8 min in diaphragm, and 9 min in soleus. Analysis of the responses revealed that the fatigue was caused by failure of more than one process in all muscles, and failure of nerve conduction did not contribute to fatigue in any muscle. Failure of neuromuscular transmission, muscle membrane excitation, and excitation-contraction (E-C) coupling and contractility accounted for 55, 45, and 0%, respectively, of the fatigue in EDL, for 21, 74, and 5% of the fatigue in diaphragm, and for 2, 54, and 44% of the fatigue in soleus. In dystrophic mice, while about 50% reduction in nerve-evoked tension occurred by 8.1 min in EDL and 5.6 min in diaphragm, only 29% reduction in tension occurred by 80 min in soleus. Failure of neuromuscular transmission, muscle membrane excitation, E-C coupling and contractility accounted for 22, 63 and 15% of the fatigue in EDL, for 21, 79, and 0% of the fatigue in diaphragm, and for 15, 59, and 26% of the fatigue in soleus. The proportion of slow-twitch oxidative fibers was more than normal in dystrophic EDL, but the same as normal in dystrophic diaphragm and soleus. The slower onset of fatigue was attributable to lesser failure of neuromuscular transmission in dystrophic EDL, and to lesser failure of E-C coupling and contractility in dystrophic soleus.
Animals↗
Isolation of a human intestinal bacterium capable of transforming barbaloin to aloe-emodin anthrone.
A strictly anaerobic bacterium, Eubacterium sp. BAR, was isolated from human feces as one of the intestinal bacteria capable of metabolizing barbaloin. The bacterium grew in PYF broth containing barbaloin and converted barbaloin to aloe-emodin anthrone. On the other hand, the bacterium had little metabolic activity in GAM broth.
Aloe↗
Effects of constituents of Beli (Aegle marmelos) on spontaneous beating and calcium-paradox of myocardial cells.
Effects of methanolic extract of root bark of Beli (Aegle marmelos Corr.), an Ayurvedic crude drug used for heart diseases, and constituents isolated from the extract on spontaneous beating of cultured mouse myocardial cells were examined. The extract at a concentration of 100 micrograms/ml inhibited the beating rate by approximately 50%. Among the isolated constituents, aurapten was the most potent inhibitor; the IC50 of aurapten is 0.6 microgram/ml, which is comparable with that of verapamil, a calcium antagonist. Addition of aurapten at concentrations higher than 1 microgram/ml significantly reduced the ratio of morphologically changed myocardial cells which originated from calcium overload caused by successive treatment with calcium-free and calcium-containing solutions.
Animals↗