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PubMed1992

[Toxicological characteristics and standardization of various poly-metallic oxides].

Acute toxicity, functional cumulative and local effects of the four ++poly-metallic oxides YBa2Cu3O7, Bi4Sr3O16, Tl2Ca2Cu3O10, Lao,7Sro,3CoO3, were studied in laboratory animals. Parallel experiments on assessment toxicity of the regular oxides of the studied metals in mice were carried out. The major dissolution of metals was shown to occur in acid medium. Thallium-barium-calcium cuprite turned out to be the most toxic and cumulative; it induced the most severe morphologic changes in the liver and kidneys. The least severe disorders caused by this substance were in the rat gastric mucosa and in rabbit eye after a conjunctival injection. Yttrium-barium cuprite induced the most severe changes at the site of injection, lanthanum-strontium cobaltite ranks second here. All copper-containing polymetallic oxides show resorptive toxicity when applied to the skin. Different types of combined toxicity are possible, that is why MACs for the regular oxides can not be used for setting the normal concentrations of ++poly-metallic oxides in air. Estimated toxicometric parameters helped to score the concentrations, which may serve as tentative safe levels of the studies substances.

Acute Disease↗
PubMed2004

Effects of incremental curing on contraction stresses associated with various resin composite buildups.

OBJECTIVE: The purpose of this study was to photoelastically evaluate contraction stresses associated with various resin composite build-up procedures, including incremental curing and the use of flowable composite for pulpless molars. METHOD AND MATERIALS: Life-sized photoelastic models of an endodontically treated molar were fabricated. The cavity represented a conservative access preparation and included four lateral walls. The following materials were used for buildup: dual-cured hybrid composite (Cleafil DC Core [DC], BIS-CORE [BC]); light-cured flowable composite (AELITEFLO LV [ALV]); and chemical-cured flowable composite (CORE-FLO [CF]). The photoelastic models were built up with the following techniques: bulk-cured (BDd [dual-cured DC], BDc [chemically-cured DC], BBd [dual-cured BC], and BC [CF]); and incremental-cured (1 mm gingivally + 3.5 mm occlusally; IAB [ALV + BC], ICB [CF + BC], and IBB [BC + BC]). Isochromatic fringes developed in the models were recorded photographically in the field of a circular polariscope, and maximum fringe order was determined. Five specimens were tested for each condition. RESULTS: Stress intensity of the build-up methods fell into two categories: high (BDd, BBd, BC, and IAB) and low (BDc, ICB, and IBB). The difference between high and low groups was statistically significant, except between BC and ICB. The maximum fringe order was developed around the point angles at the cavity floor for all the conditions tested. CONCLUSIONS: Type and setting mechanism of resin composite build-up technique had considerable influence on contraction stress. Incremental buildup using composites with low elastic modulus did not reduce contraction stress intensity compared with bulk-cured techniques.

Barium Compounds↗
PubMed2004

Microleakage of cervical cavities restored with flowable composites.

PURPOSE: To investigate the microleakage of cervical cavities restored with flowable composites in conjunction with an all-in-one adhesive system (AQ Bond) and an experimental two-step self-etching primer system (ABF) after thermocycling or flexural load cycling. METHODS: 180 wedge-shaped cervical cavities on the labial surfaces of bovine incisors were treated with AQ Bond or ABF according to the manufacturers' instructions. The treated cavities were filled with one of three flowable composites (AElite Flo, Metafil Flo or Protect Liner F). Ten of 30 specimens for each group were immersed in 0.5% basic fuchsin solution immediately after finishing of the restorations. Specimens to be subjected to thermocycling (5-60 degrees C, 15 seconds dwell time, 5000 cycles) or to flexural load cycling (approximately 0.5 mm labio-lingual displacement at the incisal edge, 10,000 cycles, 1 Hz) prior to immersion in the dye were also prepared. After 24-hour storage in the dye solution, the teeth were sectioned longitudinally through the center of the restorations, and the degrees of dye penetration scored. The microleakage scores of a hybrid composite (Clearfil AP-X) obtained from our previous study were used for comparison. The data were analyzed with the Kruskal-Wallis test and the Mann-Whitney U-test (P < 0.05). RESULTS: No significant differences in the microleakage patterns and scores were found among the flowable composites. On the other hand, significant differences in the microleakage patterns and scores were observed between the flowable and the hybrid composites. Thermocycling caused deterioration of marginal integrity, and the flowable composites showed more microleakage than the hybrid composite. In contrast, flexural load cycling did not cause deterioration of the marginal integrity when the cavities were filled with the flowable composites. Statistical analysis also revealed that the adhesive systems played a large role in the microleakage patterns.

Animals↗
PubMed2004

Evaluation of tocolytic efficacy of selective beta2 adrenoceptor agonists on buffalo uterus.

Present study was conducted on prostaglandin F2alpha (PGF2alpha), oxytocin, (OT), potassium chloride (KCI) and barium chloride (BaCl2) pre-contracted perimetrial uterine strips of dioestrus and pregnant buffaloes to evaluate the tocolytic efficacy of selective beta2 adrenoceptor agonists-albuterol (salbutamol) and terbutaline. Cumulative concentration-response curves of both the beta2 adrenoceptor agonists were constructed and the mean effective concentration (EC50) values determined and compared statistically. Based on the comparative EC50 values in relaxing the pre-contracted uterine strips with different spasmogens, the rank order potency of albuterol was found to be--PGF2alpha > BaCl2 > OT > KCl on uterine strips from dioestrus animals, while OT> BaCl2> PGF2alpha >KCl on the uterine strips of pregnant buffaloes. The rank order potency of terbutaline on uterine strips from dioestrus stage animals was- BaCl2 > OT > KCl > PGF2alpha, while BaCl2 > PGF2alpha > KCl > OT on uterine tissues of pregnant animals. Thus, irrespective of the state of uterus, whether gravid or non-gravid, KCl-depolarized uterine tissues required comparatively higher concentrations of albuterol or terbutaline to produce tocolytic effect. High concentrations of K+ in biophase may have interfered with the beta2 adrenoceptor agonists-induced outward K+ current and hyperpolarization. From the results of present study, it was evident that selective beta2 adrenergic agonists had good tocolytic efficacy on the uterus of buffaloes. Further, indirectly the possibility of existence and activation of K(Ca) channels by selective beta2 adrenoceptor agonists in mediating tocolysis of buffalo myometrium can not be ruled out, however, detailed studies using specific K(Ca) channel blockers are required for characterizing the nature of such channels in buffalo uterus.

Abortifacient Agents, Nonsteroidal↗
PubMed2004

[Anti-arrhythmic effect of starfish sterol].

AIM: To study the effect of modified starfish sterol [C03, succinic acid (5-epiandroene-17-one-3beta-ol) diester] on experimental arrhythmias. METHODS: Arrhythmias were induced by drugs (Aco, Oua, BaCl2 and adrenalin) i.v., ligating the left anterior descending coronary artery and electricity. RESULTS: C03 71.4 mg x kg(-1) (ig) was shown to increase the dose of Oua inducing VP, VT, VF and CA in guinea pigs (P < 0.01); C03 (26.8, 80.4 mg x kg(-1)) was found to increase the dose of Aco inducing VF and CA in rats (P < 0.01); C03 (8.9, 26.8, 80.4 mg x kg(-1)) increase the dose of barium chloride and delay the onset time of ventricular arrhythmias (P < 0.01); C03 (14.1, 42.3 mg x kg(-10) shorten time of recovering induced by adrenalin in rabbits (P < 0.01); C03 (80.4 mg x kg(-1)) was shown to reduce the number of ventricular arrhythmias induced by coronary artery ligation in rats (P < 0.05), C03 increase VFT induced by electricity in rabbits, VFT of C03 14.1 mg x kg(-1) increased from (5.1 +/- 2.5) V to (11.0 +/- 2.7) V (P < 0.01), 42.3 mg x kg(-1) increased from (6.1 +/- 1.7) V to (15 +/- 5) V (P < 0.01). CONCLUSION: Starfish sterol has anti-arrhythmic effect.

Aconitine↗
PubMed2004

Reaction of phosphorylated and O-glycosylated peptides by chemically targeted identification at ambient temperature.

Conditions for carrying out chemically targeted identification of peptides containing phosphorylated or glycosylated serine residues have been investigated. Ba(OH)2 was used at ambient temperature to catalyze the beta-elimination reaction at 25 degrees C. Nucleophilic addition of 2-aminoethanethiol was performed in both parallel and tandem experiments. The method was demonstrated by the reaction of beta-casein tryptic digest phosphopeptides and an O-glycosylated peptide. Contrary to an earlier report by others, the glycopeptide was found to react with essentially the same kinetics as phosphopeptides. Conversion of four phosphoserines in residues 15, 17, 18, and 19 from bovine beta-casein N-terminal tryptic phosphopeptides were followed by monitoring the time course of the addition reaction. The chemistry proceeded rapidly at room temperature with a half-reaction time of 15 min. No side-reaction products were observed; however, care was taken to minimize all counter ions that either precipitate barium or neutralize the base. Digestion of the converted peptides with lysine endopeptidase identified all five phosphoserines in the beta-casein tryptic digest. Alternatively, preincubation with base followed by nucleophilic addition of the thiol was found to work satisfactorily. The use of the water-soluble hydrochloride of 2-aminoethanethiol allowed beta-elimination, nucleophilic addition, and desalting to be carried out on a micro C18 reverse phase pipette tip.

Barium Compounds↗
PubMed1998

[FT-IR study on the solid-state reaction of bilirubin on BaF2].

Bilirubinate complexes are the main component of pigment gallstones and the recent researches suggested that bilirubin free radical plays a role in some biological processes. In this paper the solid-state reaction of bilirubin on BaF2 was examined by FT-IR. The solid-state reaction was produced by grinding the crystalline bilirubin and single crystals BaF2 together in an agate mortar. From the results the free radical mechanism is suggested in the solid-state reaction of bilirubin on BaF2. The replacement of H on NH of pyrrole by Ba2+ was prior to that of H on COOH. The structure of the resultant complex from the solid-state reaction is different compared with that from the liquid-state reaction.

Barium Compounds↗
PubMed1992

Induction of tissue factor activity in endothelial cells and monocytes by a modified form of albumin present in normal human plasma.

Molecules that induce tissue factor expression by responsive cells such as endothelial cells and monocytes may be important in the regulation of hemostasis and, perhaps, in mediating certain hemostatic disorders. A constituent of normal human plasma capable of inducing tissue factor activity in human endothelial cells and monocytes has been isolated and identified as a derivative of, or modification associated with albumin. Procoagulant albumin caused a concentration-dependent induction of tissue factor expression by human endothelial cells, but bovine endothelial cells were unresponsive. The dose-response curve developed a plateau phase, indicating that the capacity of endothelial cells to respond to the stimulus was finite. The maximum response induced by the procoagulant albumin was similar to that observed for maximally effective concentrations of endotoxin, interleukin-1, and tumor necrosis factor. Time-course studies showed that procoagulant albumin produced peak activity in 4 to 6 hours. Identification of a procoagulant form of albumin in normal human plasma suggests a potential role for this constituent in regulation of hemostasis.

Barium↗
PubMed2005

Sodium nitroprusside relaxes goat coronary artery through activation of calcium-dependent K+ channels.

In the present investigation we have examined the hypothesis that calcium-dependent K+ channels (K(Ca)) are involved in the sodium nitroprusside (SNP)-induced vasodilatation of goat coronary artery. SNP (10(-9)-3 x 10(-6) M), added cumulatively, relaxed K+ (30 mM)-contracted coronary artery ring segments in a concentration-dependent manner with an EC50 of 1.32 x 10(-7) M (95% CL, 0.93-1.86 x 10(-7) M; n = 21). K(Ca) blocker, tetraethyl ammonium (1 mM) caused a rightward shift in the concentration-response curve of SNP with a corresponding increase in EC50 (1.62 x 10(-6) M; 95% CL, 0.44-6.02 x 10(-6) M, n = 4) of nitro vasodilator. Lowering of extra cellular Ca2+ in the physiological saline solution to 1/4 of normal selectively attenuated the vasorelaxant response of SNP, thereby causing an increase in its EC50 (2.4 x 10(-6) M; 95% CL, 1.23-4.68 x 10(-6) M, n = 4). Exposure of the tissues to high K+ (80 mM) solution, a protocol adopted to reduce the K+ gradient across the cell membrane, markedly inhibited the coronary artery relaxations induced by SNP (EC50, 2.54 x 10(-6) M; 95% CL, 1.31-4.91 x 10(-6) M, n = 4), when compared with tissues contracted with low K+ (30 mM) solution (EC50 7.9 x 10(-8); 95% CL, 4.4 x 10(-8)-1.44 x 10(-7) M, n = 6). The results suggested that a major component of SNP-induced relaxation of goat coronary artery was mediated by K(Ca) channels.

Animals↗
PubMed2005

Effect of filler loading on resin cement bonding to silanized buildup composites.

PURPOSE: To determine the effects of silanation for core buildup composites on bond strength of resin cement. METHODS: Three core buildup composites including FluoroCore LV, Core Restore, and Clearfil Photo Core, of which filler loadings were 65 wt%, 74 wt%, and 83 wt% respectively, were used. All composite specimens were randomly divided into four surface treatment groups of eight each as following; 1) 600-grit ground only, 2) 600-grit ground plus silanation, 3) 600-grit ground plus air-particle abrasion, 4) air-particle abrasion plus silanation. Following these treatments, 4-META/MMA-TBB resin (C&B Metabond) was bonded to the specimen surfaces. Completed specimens were stored in 37 degree C water for 24 hours, and then thermocycled 20,000 times (4 degree C - 60 degree C) before shear bond strengths were tested. Data were analyzed by two-way ANOVA and Scheffé's test for statistical significance (P < 0.05). RESULTS: Clearfil Photo Core, of which filler loading was the highest among the resin composites tested, treated with air-particle abrasion plus silanation obtained the highest bond strength. However, silanation alone was not effective for improving the bond strength.

Air Abrasion, Dental↗
PubMed2005

[X-ray microanalysis of the activity of immobilized urease on chitosan membrane].

The localization of the activity of immobilized urease on chitosan membrane was studied by X-ray microanalysis. BaCl2 and urea were selected as the capture and substrate respectively. The substrate was hydrolyzed by immobilized urease to produce NH3 and CO2 in Tris-HCl buffer (pH 7.0), and the latter was captured by BaCl2 to form precipitate. The precipite was deposited on the active site of immobilized urease. It is shown that the method is practicable and reliable. The optimum condition for the localization of activity of immobilized urease was studied.

Ammonia↗
PubMed2005

[Luminescence properties and spectral analysis of long phosphorescent phosphors: Ba(1 - x) Ca (x) Al2O4 : Eu2+, RE3+].

New long phosphorescent phosphors Ba(1 -x),Ca(x)Al2O4 : Eu2+, RE3+ (RE3+ = Dy3+, Nd3+) with tunable color emission have been prepared by solid state reaction. The luminescence properties of the samples are discussed and analyzed. The emission spectra show that the tuning range of the color emission of the phosphors is between 498 and 440 nm, which is determined by x, under the excitation of UV. The wavelength of afterglow increases with increasing x until x equals 0.6, and when x equals 0.6, the luminescence property of Ba(1-x) Ca(x)Al2O4: Eu2+, RE3+ (RE3+ = Dy3+, Nd3+) is similar to that of CaAl2O4 : Eu2+, RE3+. The XRD measurements were performed to investigate the single phase states of the samples, and it was found that the single phase limit in the phosphors is below an x value of 0.4. The thermoluminescence curves imply that the traps in the hosts are different with different x value, which well explains the varying delay time of the samples.

Aluminum Oxide↗
PubMedDate not supplied

[Cases of Crohn's disease involving the small bowel, diagnosed by the barium contrast agent ENTERO-VU].

The paper deals with the capacities of X-ray diagnosis of Cronh's disease involving the small bowel, using the barium contract agent Entero-VU specially designed to examine the bowel. It describes 3 cases of Crohn's disease presented by its different stages and localization in the small bowel. In the author's opinion, the barium contrast agent Entero-VU designed to examine the small bowel has two basic advantages: it is easy-to-use and highly diagnostically effective.

Adult↗
PubMed2006

Delayed hypersensitivity reaction after intravenous glucagon administered for a barium enema: a case report.

INTRODUCTION: Few reports have documented allergic hypersensitivity reactions after barium gastrointestinal studies. Of these, the barium suspension, its additives or intravenous glucagon given for bowel relaxation has been implicated as possible allergens. We report a patient with delayed hypersensitivity reaction after barium enema and discuss the reasons supporting glucagon as the possible allergen. CLINICAL PICTURE: A 74-year-old Chinese woman presented with pruritic rashes, 1 day after a barium enema. Intravenous glucagon (GlucaGen, Novo Nordisk, Denmark) was administered during the barium enema. Physical examination revealed palpable purpuric rashes on the legs with erythematous papules and plaques on the arms and trunk. Skin biopsy demonstrated superficial perivascular infiltrates of lymphocytes and eosinophils, consistent with a drug eruption. TREATMENT AND OUTCOME: The rashes resolved with antihistamines and topical corticosteroids. CONCLUSION: This report highlights the potential of glucagon to cause hypersensitivity reactions. Awareness of this entity is important for the prevention and recognition of complications during barium gastrointestinal studies.

Adrenal Cortex Hormones↗
PubMed1991

Effects of the anticholinergic drug prifinium bromide on urinary bladder contractions in rat in vivo and in guinea-pig in vitro.

The parenteral and enteral effects of prifinium bromide (CAS 4630-95-9; in the following referred to as prifinium), a quaternary ammonium anticholinergic drug, were investigated on contractions of the rat urinary bladder by cystometry and compared with those of atropine, oxybutynin and terodiline. Additionally, in vitro experiments were carried out with the isolated guinea-pig detrusor muscle to clarify the mechanisms of action of these effects. In intravenous doses, all the drugs reduced the amplitude of the contractions in the cystometric studies. The inhibition was dose-dependent, but was not entirely even at the respective largest doses. According to the 40% inhibitory doses, prifinium was as active as atropine, and 10 and 100 times more active than oxybutynin and terodiline, respectively. The potency ratios of the drugs in their in vivo effects were in good agreement with those of their in vitro anticholinergic effects, which were determined with carbachol-induced contractions in the isolated guinea-pig detrusor muscle. On the other hand, in the in vitro studies, prifinium and atropine had little or no effect on contractions induced by electrical stimulation, KCl and BaCl2, whereas oxybutynin and terodiline antagonized all of the stimuli to a similar extent. These findings indicate that the anticholinergic activity of prifinium may be only one factor in the mechanisms of its in vivo inhibition of the rat bladder contractions. Finally, intraduodenal doses of prifinium also inhibited the contractions of the rat bladder, and the effects of the drug by this route were almost the same as those of oxybutynin and terodiline.

Animals↗