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PubMedDate not supplied

Effects of bifemelane on calcium and magnesium deposition in the central nervous system tissues of rats maintained on low-calcium diets.

The effects of bifemelane [4-(o-benzylphenoxy)-N-methylbutylamine hydrochloride] on the deposition of calcium and magnesium in central nervous system (CNS) tissues, heart, liver, kidney, muscle, abdominal aorta and bones were studied in rats maintained on standard and low-calcium diets. Rats were maintained for 90 days on the following diets: standard calcium (12.5 g/kg diet); standard with 100 mg/kg bifemelane; low-calcium (30 mg/kg diet); and low-calcium with bifemelane. The presence of bifemelane did not affect blood chemistry, but the magnesium concentration in the cerebellum was significantly (P less than 0.05) higher in rats receiving standard diet after bifemelane treatment. Magnesium concentrations in the pons, cerebellum, spinal cord, heart, liver and femur of bifemelane-treated rats fed low-calcium diets were significantly (P less than 0.05) higher compared with the corresponding controls, whereas the calcium concentration in the liver was significantly (P less than 0.05) lower. In general, bifemelane tended to decrease calcium deposition in the CNS and soft tissues of rats fed standard or low-calcium diets. Bifemelane may activate cerebral metabolism and maintain magnesium concentrations in the CNS and soft tissues, and be implicated in metal metabolism in rats fed low-calcium diets.

Animals↗
PubMedDate not supplied

The clinical effect of amorphous calcium phosphate (ACP) on root surface hypersensitivity.

Dentin hypersensitivity is a transient condition that often resolves with the natural sclerotic obturation of dentin tubules. A method of rapidly forming calcium phosphate compounds within these tubules can mimic sclerosis and lead to rapid reduction in hypersensitivity. Amorphous calcium phosphates (ACP) can be formed in situ by the sequential application of calcium and phosphate solutions. In this clinical study, 30 patients with reported dentin hypersensitivity were randomly assigned to parallel treatment or placebo groups. In the experimental treatment group, ACP was formed by topical application of a 1.5 mol/L aqueous solution of CaCl2 followed by topical application of 1.0 mol/L aqueous K3PO4. The placebo group was treated with a topical application of 1.0 mol/L aqueous solution of KCl followed by topical application of distilled water. Treatments were repeated at the 7-day and 28-day recall appointments. Response to air and tactile stimuli were measured immediately before treatment using a visual analog scale initially on day 1, then on days 7, 28 and 180. The results showed that both the experimental and placebo treatments resulted in a reduction in hypersensitivity at 180 days. However, the ACP treatment group showed a much more rapid reduction in hypersensitivity over time. The change in sensitivity was much more apparent using the air stimulus than the tactile stimulus. These results show that topical placement of ACP can rapidly reduce dentin hypersensitivity.

Adult↗
PubMedDate not supplied

[Inhibition of Na+-Ca2+-exchange and superoxide dismutase activity of copper-containing cryptand complexes].

It is shown that cryptand complexes containing copper inhibit sodium-calcium exchange in sarcolemma of cardiomyocytes. The complexes studied exhibit the superoxide dismutase activity. The binding of copper ions by cryptand prevents the development of cariotoxic effects of the former. Low toxicity, the combined superoxide activity and that inhibiting sodium-calcium exchange of cryptand complexes with copper (II) ions makes the further search for cardioprotective compounds perspective within the series of cryptand copper complexes.

Animals↗
PubMed1980

[Absorption of calcium by growing goats: effect of oxalates].

The influence of sodium oxalate and calcium oxalate upon calcium digestibility was studied in growing goats. Furthermore, and in the same animals, calcium absorption efficiency was estimated after performing duodenal fistula which allowed us to introduce calcium chloride or calcium oxalate and sodium oxalate, in order to avoid ruminal bacteria action upon the forementioned compounds. Finally, calcium absorption of an isolated intestine loop was studied in conscious goats with a Crocker Markowitz fistula, in the presence or absence of oxalate. The addition of sodium oxalate to the diet did not significantly decrease calcium absorption; but when calcium was given as oxalate, absorption was considerably lower. When calcium was introduced as calcium chloride through duodenal fistula, absorption was the same as when the substance was given in the diet. Calcium absorption drastically decreased when sodium oxalate was introduced directly into the duodenum, this fact is confirmed when calcium absorption is estimated in a jejunal loop, which shows that the differences found in relation to the effect of dietary sodium oxalate or directly introduced in duodenum are due to the substance destruction by ruminal bacteria.

Absorption↗
PubMed2006

Inhibition of anaphylaxis-like reaction and mast cell activation by water extract from the fruiting body of Phellinus linteus.

Mast cell-mediated anaphylactic reaction is involved in many allergic diseases such as asthma and allergic rhinitis. Phellinus linteus has been used as a traditional herb medicine in oriental countries and is known to have anti-tumor, immunomodulatory, anti-inflammatory, and anti-allergic activities. However, roles of Phellinus linteus in the mast cell-mediated anaphylactic reactions have not fully been examined. In the present study, we have investigated the effects of water extract from the fruiting body of Phellinus linteus (WEPL) on mast cell-mediated anaphylaxis-like reactions. Oral administration of WEPL inhibited the compound 48/80-induced systemic anaphylaxis-like reaction and ear swelling response. WEPL also inhibited the anti-dinitrophenyl (DNP) IgE-mediated passive systemic and cutaneous anaphylaxis. WEPL had no cytotoxicity on rat peritoneal mast cells (RPMC). WEPL dose-dependently reduced histamine release from RPMC activated by compound 48/80 or anti-DNP IgE. Moreover, WEPL decreased the compound 48/80-induced calcium uptake into RPMC. Furthermore, WEPL increased the level of intracellular cAMP and significantly inhibited the compound 48/80-induced cAMP reduction in RPMC. These results suggest that WEPL may serve as an effective therapeutic agent for allergic diseases.

Anaphylaxis↗
PubMed1994

Imidazo[1,5-a]pyrimidine and benzo[4,5]imidazo-[1,2-a]pyrimidine derivatives as calcium antagonists.

Several bicyclic dihydropyrimidines were synthesized and evaluated for their calcium antagonistic activities by comparison with the usual 1,4-dihydropyridine calcium antagonist reference compound nifedipine. The solid-state structure of the isopropyl 2-methyl-4-(3'-nitrophenyl)-1,4-dihydrobenzo[4,5]imidazo[1,2- a]pyrimido-3-carboxylate shows that these compounds can adopt the most important structural features of the 1,4-dihydropyridine and 1,4-dihydropyrimidine calcium channel blockers. The high-potassium depolarized rat aorta assay was used for testing the compounds as calcium channel blockers. Some compounds showed interesting vasorelaxant activity.

Animals↗
PubMed1994

Diphenylene iodonium blocks K+ and Ca2+ currents in type I cells isolated from the neonatal rat carotid body.

Diphenylene iodonium (DPI), an inhibitor of NAD(P)H oxidase, blocks hypoxic excitation of the carotid body. We used the whole-cell patch-clamp technique to investigate the actions of DPI on ionic currents in isolated type I carotid body cells. DPI (10 microM) caused reversible blockade of K+ and Ca2+ currents in these cells, indicating that DPI is a non-selective ion channel blocker. Since hypoxic excitation of the carotid body is dependent on Ca2+ influx into type I cells, our observation that DPI blocks Ca2+ currents in type I cells can account for the ability of this compound to inhibit hypoxic excitation of the intact organ.

Animals↗
PubMed2005

Formation of hydroxyapatite onto glasses of the CaO-MgO-SiO2 system with B2O3, Na2O, CaF2 and P2O5 additives.

New bioactive glasses with compositions based on the CaO-MgO-SiO(2) system and additives of B(2)O(3), P(2)O(5), Na(2)O, and CaF(2) were prepared. The in vitro mineralization behaviour was tested by immersion of powders or bulk glasses in simulated body fluid (SBF). Monitoring of ionic concentrations in SBF and scanning electron microscopy (SEM) observations at the surface of the glasses were conducted over immersion time. Raman and infrared (IR) spectroscopy shed light on the structural evolution occurring at the surface of the glasses that leads to formation of hydroxyapatite.

Biocompatible Materials↗
PubMed2005

Alginate microparticles prepared by spray-coagulation method: preparation, drug loading and release characterization.

A spray-coagulation method was developed for the preparation of large scale of porous alginate microparticles. The effect of three variables on porosity was evaluated: (1) alginate solution concentration (2) the concentration of CaCl2 in the coagulation medium and (3) the ratio of guluronic acid to manuronic acid of the alginate. Methylene blue (MB), a highly water-soluble compound and a practically water-insoluble compound, 4-phenylazoaniline (PAA) were used as the model drugs to study drug loading and release characteristics from alginate microparticles. The release of the model compounds from the microparticles was found to depend upon the release medium. Incomplete in vitro release of both model drugs in deionized (DI) water was observed. The release of MB in simulated gastrointestinal fluid (0.1N HCl) was fast and complete, while the release of PAA was slow in 0.1N HCl and fast in phosphate buffer solution (pH 6.8). Interactions between the model drugs and alginate microparticles were identified from scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) analysis. The results indicated that (1) porous alginate microparticles can be produced by the spray-coagulation method; (2) drugs can be loaded by the adsorption method; (3) and the obtained microparticles may be used for delaying the release of drugs of low water solubility in acidic conditions.

Adsorption↗
PubMed2003

The effect of various intracanal oxidizing agents on the push-out strength of various perforation repair materials.

OBJECTIVE: The purpose of this study was to determine the effect of intracanal oxidizing agents on the strength of materials used to repair root perforations. STUDY DESIGN: Standardized perforations in bovine root samples were repaired with mineral trioxide aggregate (MTA), Super-EBA cement (S-EBA), or intermediate restorative material (IRM). After 7 days, 10 samples from each group were tested for push-out strength with an Instron machine (controls). The remaining samples were immersed in NaOCl, sodium perborate mixed with saline (SPB+S), Superoxol (SO), sodium perborate mixed with Superoxol (SPB+SO), or saline for 7 days to investigate the effect of irrigating and walking bleach compounds on the perforation repair materials. Push-out strength values were compared with those of the dry materials to determine whether any loss of integrity had occurred. RESULTS: MTA was statistically significantly less resistant across conditions to displacement than S-EBA or IRM. IRM was consistent across treatment conditions, whereas S-EBA lost strength when exposed to NaOCl, SPB+S, or SPB+SO. Exposure to SPB+S had the greatest effect on all 3 materials. CONCLUSIONS: IRM performed consistently as a perforation repair material despite exposure to oxidizing agents, whereas MTA was less resistant to dislodgement than either IRM or S-EBA and was more affected than IRM by sodium perborate-containing bleaching solutions.

Aluminum Compounds↗
PubMed1997

Rehydration of desiccated Baralyme prevents carbon monoxide formation from desflurane in an anesthesia machine.

BACKGROUND: Desiccated carbon dioxide absorbents degrade desflurane, enflurane, and isoflurane to carbon monoxide (CO) in vitro and in anesthesia machines, which can result in significant clinical CO exposure. Carbon monoxide formation is highest from desflurane, and greater with Baralyme than with soda lime. Degradation is inversely related to absorbent water content, and thus the greatest CO concentrations occur with desflurane and fully desiccated Baralyme. This investigation tested the hypothesis that rehydrating desiccated absorbent can diminish CO formation. METHODS: Baralyme was dried to constant weight. Carbon monoxide formation from desflurane and desiccated Baralyme was determined in sealed 20.7-ml vials without adding water, after adding 10% of the normal water content (1.3% water), and after adding 100% of the normal water content (13% water) to the dry absorbent. Similar measurements were made using an anesthesia machine and circle system. Carbon monoxide was measured by gas chromatography-mass spectrometry. RESULTS: Carbon monoxide formation from desflurane in vitro was decreased from 10,700 ppm with desiccated Baralyme to 715 ppm and less than 100 ppm, respectively, when 1.3% and 13% water were added. Complete rehydration also decreased CO formation from enflurane and isoflurane to undetectable concentrations. Desflurane degradation in an anesthesia machine produced 2,500 ppm CO in the circuit, which was reduced to less than 180 ppm when the full complement of water (13%) was added to the dried absorbent. CONCLUSIONS: Desflurane is degraded by desiccated Baralyme in an anesthesia machine, resulting in CO formation. Adding water to dried Baralyme is an effective means of reducing CO formation and the risk of intraoperative CO poisoning. Although demonstrated specifically for desflurane and Baralyme, rehydration is also applicable to enflurane and isoflurane, and to soda lime.

Anesthesia, Inhalation↗
PubMed2003

The effect of irrigation with doxycycline or citric acid on leakage and osseous wound healing.

This study investigated the effect of doxycycline irrigation on wound healing and the apical seal of three filling materials. Part 1: 220 extracted teeth received root canal therapy followed by root resection (2 mm) and ultrasonic root end preparations (3 mm). Groups of 20 were irrigated with saline, citric acid, or doxycycline and filled with amalgam, Super EBA, or MTA. Leakage was measured (mm) after decalcification and clearing. Part 2: two defects were made on each side of the mandible of 10 New Zealand rabbits. On each side, one defect was irrigated with saline and one with either citric acid or doxycycline. The animals were killed in groups of five at 9 and 18 days. Sections of each defect were stained with hematoxylin and eosin for evaluation of healing and bone fill. Super EBA and MTA leaked significantly less than amalgam, regardless of irrigant. Leakage after irrigation with doxycycline compared to citric acid or saline was not significantly different for Super EBA or MTA but was lower for amalgam. There was no significant difference in healing or bone fill among irrigants at 9 or 18 days.

Aluminum Compounds↗
PubMed2004

Hard-tissue healing after application of fresh or set MTA as root-end-filling material.

The purpose of this study was to compare the effect of fresh mineral trioxide aggregate (MTA) with set MTA on hard-tissue healing after periradicular surgery. The root canals of 24 mandibular premolars in four 2-yr-old beagle dogs were filled with MTA. Two weeks later the root ends of half of the samples were surgically exposed and resected to the set MTA within the canals. After exposing and resecting the other 12 root ends, they were prepared with ultrasonic instrumentation and preparations were filled with fresh MTA. After 4 months, the animals were killed. Hard-tissue healing was analyzed histomorphometrically. The results indicated that although freshly placed MTA resulted in a significantly higher incidence of cementum formation (12 of 12 versus 8 of 12, p = 0.028), there is no significant difference in the quantity of cementum or osseous healing associated with freshly placed or set MTA when used as root-end-filling material.

Aluminum Compounds↗
PubMed2001

One-visit apexification: technique for inducing root-end barrier formation in apical closures.

Numerous procedures and materials have been utilized to induce root-end barrier formation. Mineral trioxide aggregate (MTA) was introduced to dentistry as a root-end filling material. It has been advocated for filling root canals, repairing perforations, pulp capping, and root-end induction. Mineral trioxide aggregate reacts with tissue fluids to form a hard tissue apical barrier. As a result, MTA shows promise as a valuable material for use in one-visit apexification treatment, primarily for treating immature teeth with necrotic pulps.

Aluminum Compounds↗