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At least 649 records · Page 36Linked to original sources
PubMed1999

Effects of Keishi-ka-shakuyaku-to (Gui-Zhi-Jia-Shao-Yao-Tang) on diarrhea and small intestinal movement.

The present study was conducted to determine the characteristics of the effects of Keishi-ka-shakuyaku-to (Gui-Zhi-Jia-Shao-Yao-Tang; TJ-60) on diarrhea. Significant repression was noted by TJ-60 at 1000 mg/kg, p.o. for diarrhea induced by pilocarpine, barium chloride or castor oil. Under normal conditions, TJ-60 did not influence small intestinal transit by its oral treatment even at 1000 mg/kg, however, it dose-dependently improved the acceleration of such transit caused by neostigmine. TJ-60 did not influence the resting tonus in isolated small intestine, but did selectively inhibit low frequency electrostimulated contractions. These results indicate that the antidiarrheal effects of TJ-60 may be due to the inhibition of excessively accelerated small intestinal movement, and that the inhibition of acetylcholine release by parasympathetic nerves is partly involved in the mechanism of this antidiarrheal action.

Animals↗
PubMed1988

A non-opioid mechanism in the inhibitory effect of ginseng saponins on electrically evoked contractions of guinea-pig ileum and mouse vas deferens.

Both ginseng total saponins (GTS) and one of its constituents, protopanaxatriol saponins (PT), inhibited the electrically evoked contractions of guinea-pig ileum (GPI) in a concentration dependent manner in a range of 1-100 micrograms/ml, and this effect was irreversible at high concentrations of the saponins. Protopanaxadiol saponins (PD) had a transient and weak effect. On the other hand, in mouse vas deferens (MVD), the contractions were increased by PT and PD, however, GTS was almost without effect. The inhibitory effect of morphine was arithmetically increased by pretreatment with 100 micrograms/ml of these saponins in GPI preparations, while the inhibitory effect of the contractions was potentiated in MVD preparations. Neither the inhibition of contractions in the GPI preparation nor the facilitation of contractions in the MVD preparation by these ginseng saponins was reversed by 1 microM naloxone, in contrast to naloxone antagonism of morphine-induced contractions in both preparations. GTS and PT caused a dose-dependent inhibition of BaCl2-induced contraction of GPI. It is concluded that the mechanism on the inhibitory or facilitated effect of ginseng saponins on electrically evoked contractions in GPI and MVD preparations may be separated from the effect of opioids, and the mechanism may be based on the direct action of the saponins on smooth muscles preparations.

Animals↗
PubMed1986

Liver and plasma levels of descarboxyprothrombin (PIVKA II) in vitamin K deficiency in rats.

Descarboxyprothrombin (PIVKA II) is a precursor of prothrombin without biological activity, and it increases with vitamin K deficiency. We studied the time course changes in liver and plasma levels of PIVKA II during the progress of vitamin K deficiency in rats. Good correlation was observed between liver PIVKA II and plasma PIVKA II and between liver or plasma PIVKA II and plasma prothrombin in experiments in which rats were fed a vitamin K-deficient diet. Feeding of a vitamin K-deficient diet or fasting caused marked increases in liver and plasma PIVKA II in male rats and a weaker response in female rats. Warfarin, a vitamin K antagonist, caused an abrupt increase in liver PIVKA II, but the increase in plasma PIVKA II was delayed about 3 hr. Plasma prothrombin decreased from about 30 min later. Factor VII decreased similarly to prothrombin, and changes in the prothrombin time and activated partial thromboplastin time were slower than the changes in these substances. Sex differences were not seen in these warfarin actions. These observations indicate that liver and plasma PIVKA II are sensitive markers of vitamin K deficiency in rats, and assay of PIVKA II can be useful for analyzing the action mechanism of drugs which influence blood coagulation.

Animals↗
PubMed1989

Different sensitivity changes of canine and simian femoral arterial and venous constrictions by cooling.

Using the cannula inserting method, effects of cooling (from 37 degrees C to 27 degrees C) on norepinephrine (NE)- and KCI-induced vasoconstrictions were investigated in isolated, perfused simian and canine femoral arteries and veins. KCI-induced constrictions were much greater in simian vessels than in canine vessels. NE-induced constrictions were similar in both arteries, but were greater in simian veins than in canine veins. In both arteries, NE- and KCI-induced vasoconstrictions were markedly depressed to almost the same degree by cooling. In both veins, the vasoconstrictions were not significantly affected by cooling.

Acetylcholine↗
PubMed1997

Increase of catalytic activity of alpha-chymotrypsin by metal salts for transesterification of an amino acid ester in ethanol.

alpha-Chymotrypsin-catalyzed transesterification of N-acetyl-L-tyrosine methyl ester in ethanol was markedly accelerated by addition of small amounts of divalent metal salts. The reaction rate dependent not only on the nature of metal ions but also on the nature of anionic counter ions. Calcium acetate was the most effective among the metal salts used. The reaction followed Michaelis-Menten kinetics, and it was found that the reaction increase is due to the increase in kcat.

Amino Acids↗
PubMed2000

Contemporary resin-based composite materials for direct placement restorations: packables, flowables and others.

Resin-based composite (RBC) materials are composed of principal and diluent monomers, fillers, coupling agents and other components. These materials have been developed in recent years to produce packable and flowable materials, and materials which may release ions under specific conditions and which may contain fibres. Materials which are organic-inorganic copolymers have also become available. Long term clinical trial data are not available for the most recently introduced materials.

Aluminum Silicates↗
PubMedDate not supplied

Nonselective cation current in rabbit ventricular myocytes.

Currents contributing repolarization in rabbit ventricular myocytes are very complex because the I(to.s) covers almost the whole repolarization phase of the action potential. The other components of repolarizing currents, such as I(Kr) and I(Ks), are small. In the present work, with whole-cell patch-clamp technique, a clear evidence was provided for the existence of a hitherto unreported, voltage-dependent, nonselective cation current (NSCC) in rabbit ventricular myocytes. Na(+), K(+), and Cs(+) can permeate through the nonselective cation channel and the NSCC can be blocked by Gd(3+). The channels are sensitive to Ca(2+), Mg(2+)-free, and insulin in bathing solution. Activation of NSCC may provide complex effects on action potential configuration depending on the basal conditions and the experimental situations. Considering the voltage dependence and rapid activation kinetics of this current, we speculate that this current can provide an important influence on all repolarization phases of the action potential as well as contribute to the resting membrane potential in rabbit ventricular myocytes. In addition, it is conceivable that, under certain pathophysiological conditions (e.g., ischemia or excessive mechanical stress), the sensitivity of the channels could be altered in such a way that the conductance opens even in the presence of physiological Ca(2+), Mg(2+), and insulin. It might be an important factor on the repolarization of the action potential. Changes in NSCC may lead to an induction or inhibition of arrhythmia.

4-Aminopyridine↗
PubMed2005

Characterization of MBa2Cu3O7-x thin films by Raman microspectroscopy.

Thin film embodiments of MBa2Cu3O7-x (MBCO, M = yttrium or a rare-earth metal) prepared by several different deposition methods on a variety of substrates were investigated by Raman microspectroscopy. Several of the unique characterization capabilities of Raman spectroscopy in the analysis of MBCO thin films are highlighted by the results of these investigations. The Raman active phonons of the orthorhombic and tetragonal forms of MBCO that are most useful for characterization of textured MBCO films are diagrammed and discussed. A rapid procedure for qualitative texture mapping of MBCO thin films using Raman microscopy techniques is presented, and a new approach for investigating phase separation at the sub-micrometer level in MBCO thin films based on curve resolution of the MBCO Cu2 phonon is described. The assignment of a particular feature often observed in Raman spectra of MBCO films to cation disorder is reinforced by results of a cation substitution study. The depth of penetration of the laser into MBCO films and the type of information that can be obtained by varying the extent of defocusing of the laser are also discussed.

Barium Compounds↗
PubMed2003

Depth of cure and microleakage with high-intensity and ramped resin-based composite curing lights.

BACKGROUND: The authors conducted a study to determine whether high-intensity curing lights in high and ramped intensity modes affect microleakage of resin-based composite restorations and whether different types of resin-based composites meet American National Standards Institute/American Dental Association Specification no. 27 (1993): 7.7 for depth of cure when polymerized using these lights. METHODS: The authors compared five high-intensity lights, three plasma arc lights and two quartz-tungsten-halogen lights in their regular and ramped intensity modes with a quartz-tungsten-halogen 40-second light. The parameters tested were microleakage one month after bonding and curing depth for different resin-based composite types. The authors measured curing depth using a scratch test. RESULTS: Light curing with Optilux 501 (Kerr/Demetron, Orange, Calif.) for 10 seconds and ADT Power PAC (American Dental Technologies, Corpus Christi, Texas) for 10 seconds resulted in higher microleakage values than light curing with other lights (P < .05). The microhybrid resin-based composite was the only material that met the specification when light cured with all of the lights tested. The flowable resin-based composite did not meet the specification when light cured with all lights tested. Microhybrid resin-based composite had the greatest depth of cure, and flowable resin-based composite had the least depth of cure. CONCLUSIONS: Microhybrid resin-based composite microleakage is affected by some light-curing modes. Different categories of resin-based composites are cured to different depths using high-intensity lights. CLINICAL IMPLICATIONS: Light curing with some high-intensity lights compared with halogen lights may result in higher microleakage values. Use caution when light curing flowable resin-based composite with the high-intensity lights. Place increments less than 2 millimeters in depth when using this material.

Analysis of Variance↗
PubMed1985

Potassium transport in isolated cerebral microvessels from the rat.

Microvessels have been prepared from the gray matter of a rat brain by a technique involving density gradient centrifugation. A suspension of these vessels, largely capillaries, was incubated in vitro in order to investigate K transport. The flux of K (as 86Rb) into and out of endothelial cells was estimated. Potassium influx was sensitive to temperature and pH of the medium, and was markedly inhibited by 1 mM ouabain (45%). Ouabain did not inhibit K efflux, as anticipated, when Na-K pumps are mainly located on the abluminal plasma membrane of the endothelial cell. The ouabain-sensitive K influx was measured at varying external concentrations of K. The Km of ouabain-sensitive K influx was 2.95 mM, which is similar to the affinity of the transport carrier of K, found in in vivo studies of K efflux from brain to the blood system. Both 1 mM furosemide and 5 mM barium chloride inhibited part of the ouabain-insensitive K influx. Potassium efflux was not influenced by furosemide, but was somewhat reduced by barium chloride. Noradrenalin (10(-3) mM) and histamine (0.1 mM) did not significantly affect the influx of K.

Animals↗
PubMed1989

Potassium channel blockers inhibit anion secretion in cultured rat epididymal epithelium.

The effect of putative K channel blockers on anion secretion has been studied in primary monolayer cultures of rat epididymal cells using the short circuit current technique. Under basal conditions, monolayers had a transepithelial potential difference of about 2-3 mV, apical side negative and a short circuit current (SCC) of about 2 microA.cm-2. The transepithelial resistance was about 500 omega.cm2. Addition of adrenaline (0.23 microM, basolaterally) caused the SCC to rise to a peak value of about 10.5 microA.cm-2 and then stabilized at about 4 microA.cm-2 after 15 min. This rise in the short circuit current has previously been shown to be due to an increase in net anion secretion from the basolateral to the apical medium. In tissues stimulated with adrenaline, addition of barium (Ba) to the apical side did not affect the adrenaline-induced SCC, but addition to the basolateral side caused a dose-dependent inhibition of the current with an IC50 value (concentration required to inhibit 50% of the current) of 0.92 mM. At Ba concentration of 5 mM, the adrenaline-induced SCC was completely abolished. There was no effect on transepithelial resistance. Addition of tetraethylamonium (TEA) (16 mM) to the apical or basolateral side had no significant effect on the adrenaline-stimulated SCC. Lidocaine and quinidine inhibited the adrenaline-stimulated SCC when added either to the apical or basolateral bathing solution. The IC50 values for lidocaine were 0.42 mM and 0.35 mM for basolateral and apical application, respectively. The IC50 values for quinidine were 0.062 mM and 0.050 mM for basolateral and apical application, respectively. In all cases there was no change in tissue resistance. It is proposed that in the basolateral membrane of the epididymal cells, there is a component which is sensitive to putative K channel blockers. It is likely that it is a K channel. As in other secretory cells, this channel plays an important role in secretion.

Animals↗
PubMed2002

Effect of hydrochloric acid, pepsin, or taurocholate on bioelectric properties of gastric squamous mucosa in horses.

OBJECTIVE: To determine the effect of pH with or without pepsin or taurocholic acid on the bioelectric properties of gastric squamous mucosa in horses. SAMPLE POPULATION: Gastric tissues obtained from 16 adult horses that did not have evidence of gastric disease. PROCEDURE: Bioelectric properties of squamous mucosa were determined, using modified Ussing chambers. Tissues then were exposed to mucosal pepsin (1 mg/ml) or taurocholic acid (2.5 mM) under neutral (pH 74) or acidic (pH 1.7) conditions. RESULTS: Exposure of mucosal sheets to an acidic pH resulted in an immediate and sustained decrease in transmembrane potential difference and calculated tissue resistance. Pepsin or taurocholic acid did not significantly affect bioelectric variables when added to a mucosal bath solution of pH 7.4. A synergistic effect between pepsin or taurocholic acid and mucosal acidification was not detected. CONCLUSIONS AND CLINICAL RELEVANCE: Mucosal acidification with or without pepsin or taurocholic acid resulted in reduced tissue resistance. These data support the contention that squamous erosions or ulcers in horses are mediated, in part, by prolonged exposure of gastric squamous mucosa to luminal acid.

Acetazolamide↗
PubMed1993

Intracytoplasmic barium salts in pleural fluid.

Cytological examination of the pleural effusion fluid obtained from a 66-yr-old Chinese lady showed numerous intra- and extracytoplasmic colourless refractile non-birefringent crystals. X-ray analysis of the crystals identified barium salts. On further inquiry, it was learnt that the fluid obtained had been placed in a specimen bottle provided by the x-ray department. This container was presumably contaminated with barium salts. The case highlights an unusual aspect of specimen contamination and the usefulness of x-ray analysis in the identification of crystals/substances.

Aged↗
PubMed1985

86-Rb efflux in normal and cataractous human lenses.

86Rb efflux has been studied in normal lenses and in human senile cataracts. The rate constant (Ki) of the efflux gradually increases in cataractous lenses with progression of lens damage. Efflux experiments run in the presence of BaC12 suggest that a progressive activation of BaC12 inhibitable efflux routes occurs in cataractous lenses. In the final stages of opacification the ineffectiveness of BaC12 enriched or Ca++ free media on the efflux suggests that a direct disruption of the lens membranes has occurred.

Aged↗
PubMed1990

Direct stimulation by succinate of Na+:K+ pump in rabbit ciliary epithelium.

The effects of succinate on the intracellular potential difference, PDI, were measured in isolated rabbit ciliary processes. Concentration-dependent increases in the hyperpolarization of PDI occurred between 1 and 15 mM succinate in NaCl Ringers. With 5 mM succinate, there was a 6 mV hyperpolarization. Even though the hyperpolarization of PDI was comparable with 10 and 15 mM succinate, it was more sustained at the latter two concentrations. Succinate also elicited comparable hyperpolarizations of PDI in either Cl(-)-free or HCO3(-)-free Ringers. Similarly, following incubation with either 0.1 mM DIDS or 3 mM BaCl2 the effect of succinate on PDI was unchanged. Five mM succinate had no effect if it was added after 5 mM malonate. Malonate (5 mM) rapidly reversed a 5 mM succinate-induced hyperpolarization of PDI which also suggests a metabolically mediated effect on PDI. An isosmotic substitution of Na+ with NMDG Ringers depolarized PDI, whereas PDI depolarized biphasically during exposure to 0.1 mM ouabain. The addition of 5 mM succinate had no effect on either the time course or the magnitude of the depolarization of PDI during blocking of the Na+:K+ pump with either Na(+)-free Ringers or ouabain. Taken together, these results show that succinate selectively stimulates the Na+:K+ pump, but has no effect on any Cl-, HCO3- or a Ba2(+)-sensitive K+ conductance.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1993

Active chloride transport in the pigmented rabbit conjunctiva.

The present study demonstrates, for the first time, that the excised pigmented rabbit conjunctiva is a tight barrier capable of active Cl- transport. The transepithelial potential difference was 17.7 +/- 0.8 mV (tear-side negative), the short-circuit current was 14.5 +/- 0.7 microA/cm2, and the transconjunctival resistance was 1.3 +/- 0.1 k omega.cm2 for n = 45 tissues. Various inhibitors including ouabain (a Na+/K(+)-ATPase inhibitor), amiloride (a Na+ transport blocker), N-phenylanthranilic acid (a chloride transport inhibitor), bumetanide (an inhibitor of Na(+)-(K+)-Cl- cotransport process), and BaCl2 (a K+ channel blocker) were used on the mucosal and serosal sides of the tissue mounted in Ussing chambers to determine the involvement of the respective ion transport processes in the observed short-circuit current across the conjunctiva. The results suggest that a Cl- conductive pathway is present on the mucosal side of the conjunctiva, whereas Na+/K(+)-ATPase, Na(+)-(K+)-Cl- cotransport process, and K+ conductive pathways are present on its serosal side. Amiloride-sensitive Na(+)-conductive pathways do not appear to be present on either side of the pigmented rabbit conjunctiva.

Animals↗