Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Gallium”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,315 records · Page 73Linked to original sources
PubMed2006

Influence of an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser on the reestablishment of the biocompatibility of contaminated titanium implant surfaces.

BACKGROUND: The aim of the present study was to evaluate the influence of an erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG laser [ERCL]) on 1) the surface structure and biocompatibility of titanium implants and 2) the removal of plaque biofilms and reestablishment of the biocompatibility of contaminated titanium surfaces. METHODS: Intraoral splints were used to collect an in vivo supragingival biofilm on sand-blasted and acid-etched titanium disks for 24 hours. ERCL was used at an energy output of 0.5, 1.0, 1.5, 2.0, and 2.5 W for the irradiation of 1) non-contaminated (20 and 25 Hz) and 2) plaque-contaminated (25 Hz) titanium disks. Unworn and untreated non-irradiated, sterile titanium disks served as untreated controls (UC). Specimens were incubated with SaOs-2 osteoblasts for 6 days. Treatment time, residual plaque biofilm (RPB) areas (%), mitochondrial cell activity (MA) (counts per second), and cell morphology/surface changes (scanning electron microscopy [SEM]) were assessed. RESULTS: 1) ERCL using either 0.5, 1.0, 1.5, 2.0, or 2.5 W at both 20 and 25 Hz resulted in comparable mean MA values as measured in the UC group. A monolayer of flattened SaOs-2 cells showing complete cytoplasmatic extensions and lamellopodia was observed in both ERCL and UC groups. 2) Mean RPB areas decreased significantly with increasing energy settings (53.8 +/- 2.2 at 0.5 W to 9.8 +/- 6.2 at 2.5 W). However, mean MA values were significantly higher in the UC group. CONCLUSION: Within the limits of the present study, it was concluded that even though ERCL exhibited a high efficiency to remove plaque biofilms in an energy-dependent manner, it failed to reestablish the biocompatibility of contaminated titanium surfaces.

Adult↗
PubMed2007

Etching enamel for orthodontics with an erbium, chromium:yttrium-scandium-gallium-garnet laser system.

OBJECTIVE: To test the shear bond strength, surface characteristics, and fracture mode of brackets that are bonded to enamel etched with an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser operated at different power outputs: 0.5 W, 1 W, and 2 W. MATERIALS AND METHODS: Human premolars that had been extracted for orthodontic purposes were used. Enamel was etched with an Er,Cr:YSGG laser system operated at one of three power outputs or with orthophosphoric acid. RESULTS: The shear bond strength associated with the 0.5-W laser irradiation was significantly less than the strengths obtained with the other irradiations. Both the 1-W and 2-W laser irradiations were capable of etching enamel in the same manner. This finding was confirmed by scanning electron microscopy examination. The evaluation of adhesive-remnant-index scores demonstrated no statistically significant difference in bond failure site among the groups, except for the 0.5-W laser-etched group. Generally, more adhesive was left on the enamel surface with laser irradiation than with acid etching. CONCLUSION: The mean shear bond strength and enamel surface etching obtained with an Er,Cr: YSGG laser (operated at 1 W or 2 W for 15 seconds) is comparable to that obtained with acid etching.

Analysis of Variance↗
PubMed1999

Bactericidal effect of 0.95-mW helium-neon and 5-mW indium-gallium-aluminum-phosphate laser irradiation at exposure times of 30, 60, and 120 seconds on photosensitized Staphylococcus aureus and Pseudomonas aeruginosa in vitro.

BACKGROUND AND PURPOSE: Studies have demonstrated a bactericidal effect of laser irradiation when lasers with power outputs of (6 mW are directed toward pathogenic or opportunistic bacteria previously treated with a photosensitizing agent. The purpose of this study was to determine the bactericidal capabilities of irradiation from lasers with power outputs of less than 6 mW on photosensitized microorganisms. METHODS: Two bacteria that commonly infect skin lesions, Staphylococcus aureus and Pseudomonas aeruginosa, were used. The 2 lasers used, the 0.95-mW helium -neon laser and the 5-mW indium-gallium-aluminum-phosphate laser, emit light at a wavelength close to the absorption maxima of the sensitizing agent chosen, toluidine blue O. This agent was used because of its proven effectiveness in sensitizing bacteria. For each bacterial strain, toluidine blue O was added to a 108 cells/mL solution until a 0.01% weight/volume ratio was obtained. These mixtures were spread on agar-coated petri dishes, which were then exposed to 1 of the 2 lasers for 30, 60, and 120 seconds. The cultures were then grown overnight and examined for one or more visible zones of inhibition. The areas surrounding the irradiated zone provided a control for the effects of toluidine blue O alone. To determine the effects of laser irradiation without prior toluidine blue O sensitization, separate plates were established using unsensitized bacteria. RESULTS: Although inconsistencies between plates were noted, both lasers produced at least one zone of inhibition in both bacterial species at all 3 time periods. The 5-mW laser, however, produced a greater number of these zones. CONCLUSION AND DISCUSSION: Laser-induced microbial killing of photosensitized organisms could have clinical applications in the treatment of infected skin lesions, pending in vivo studies.

Colony Count, Microbial↗
PubMed1976

Thyroid scanning with gallium-67 and cesium-131.

The roles of 131Cs and 67Ga in the evaluation of solitary thyroid nodules were investigated. Radionuclide scans were performed with 67Ga and 131I in 27 patients and with 131Cs and 131I in 43 patients. Gallium-67 detected only two of eight malignant nonfunctioning nodules and 131Cs detected one of three such nodules. The contribution of 131Cs and 67Ga to the preoperative identification of malignant thyroid lesions is of doubtful value.

Adenocarcinoma↗
PubMed1999

[Dimerization of aluminum, zinc, vanadium and gallium phthalocyanine-sulfonates in water, aqueous alcoholic solutions and micelles].

The dimerization of Aluminum (III),Vanadium(lV), Gallium(III) tetrasulfonated phthalocyanine (AlTSPc, VOTSPc, GaTSPc) and Zinc(II) bisulfonated phthalocyanine (ZnBSPc) was studied by spectrophotometic method. The dimerization constants KD were calculated from absorbance measurements. The absorption spectra in water, aqueous alcoholic solutions and micelles of phthalocyanine sulfonates aluminum shows the "slow-forming dimer", and VOTSPc, GaTSPc, ZnBSPc show contact dimer formation.

English Abstract↗
PubMed2006

[Study on the spectral properties of gallium-phthalocyanine-chloride doped composite gel glass].

One of the focal topics in the field of phthalocyanine research is its materialization for practical use. The present paper reports the encapsulation of gallium phthalocyanine chloride (GaPcCl) into silica gel glass to make homogeneously doped composite by sol-gel technique. The spectral properties of the composite gel glass were carried out by IR, UV-Vis and fluorescence measurements. The results show that the introduction of GaPcCl doesn't make noteworthy changes in the IR spectra of silica gel glass matrix. The absorption of GaPcCl dimers increases compared with DMF solution. The fluorescence intensity of GaPcCl is greatly enhanced in the composite gel glass.

English Abstract↗
PubMed2006

[Study on photoluminescence of 8-hydroxyquinaldine gallium acrylate and methyl methacrylate copolymer].

A new copolymer of 8-hydroxyquinaldine gallium acrylate and methyl methacrylate was prepared. The composition and properties of the copolymer were characterized by FTIR, UV-Vis, DSC, TG and fluorescence spectra. A strong blue-green photoluminescence, with the peak at 496 nm, was observed for the copolymer/CHCl3 solution. Effect of monomer ratio and concentration on the photoluminescence property of the copolymer was investigated. The results showed that the maximum fluorescence intensity was attained when Ga(Mq)2A: MMA was 1:20, the maximum excitation wavelength is approximately 263 nm when the concentration of the copolymer is under 2 g x L(-1), but the maximum excitation wavelength exceeds 365 nm when the concentration is above 4 g x L(-1). The copolymer was soluble in chloroform, acetone, and DMF at 25 degrees C, so it could be easier to prepare electroluminescent device by spin-coat technology.

English Abstract↗
PubMed1988

Gallium detection of Salmonella costochondritis.

A case of Salmonella costochondritis developed at a traumatic focus in a 37-yr-old Hispanic male without hemoglobinopathy or systemic disease. Bone scans and gallium scans were initially positive and remained abnormal, despite a variable clinical course and repeatedly negative serology and blood cultures. Scintigraphy was valuable for both detection and monitoring of antibiotic treatment, as well as providing localization for subsequent surgical resection.

Adult↗
PubMed1995

Effect of gallium-porphyrin analogue ATX-70 on nitroxide formation from a cyclic secondary amine by ultrasound: on the mechanism of sonodynamic activation.

Sonodynamic therapy is a promising new modality for cancer treatment based on the synergistic effect on tumor cell killing by combination of a drug (typically a photosensitizer) and ultrasound. The mechanism of sonodynamic action was suggested to involve photoexcitation of the sensitizer by sonoluminescent light, with subsequent formation of singlet oxygen. In this work we studied the aqueous sonochemical reactions of the gallium-porphyrin derivative ATX-70, one of the most active sonodynamic agents found, using 50 kHz ultrasound. The experiments were carried out in the presence of 2,2,6,6-tetramethyl-4-piperidone hydrochloride (TMP), which reacts with singlet oxygen or .OH radicals to give the EPR-detectable nitroxide 2,2,6,6-tetramethyl-4-piperidone-N-oxyl (TMP-NO). Recently it has been suggested that the enhancement of TMP-NO yields in the presence of aqueous solutions of ATX-70 exposed to ultrasound was evidence for the formation of singlet oxygen in the system. Our results show that the surfactant cetyltrimethylammonium bromide (CTAB) can mimic the ATX-70-induced increase in the TMP-NO signal, but it fails to reproduce the behavior of ATX-70 in D2O: while the yields of TMP-NO in the presence of ATX-70 increase in D2O, the opposite effect was found with the surfactant CTAB. However, our data show that the increased TMP-NO yields in D2O are paralleled by an increased concentration of ATX-70 dimer, a form that is inactive in the photochemical generation of singlet oxygen. Our finding that the ATX-70-dependent enhancement of the TMP-NO signal was highest at approximately 20% O2, in both N2/O2 and argon/O2 mixtures, and decreased with increasing oxygen concentration is not compatible with the singlet oxygen mechanism. Finally, our results on the temperature dependence of the ATX-70-induced formation of TMP-NO are not consistent with the photochemical excitation of ATX-70 by sonoluminescent light: the ATX-70-dependent enhancement of TMP-NO signal increased with temperature in the range 10-25 degrees C, while the intensity of sonoluminescence of aqueous solutions both in multiple-bubble fields and in single-bubble experiments is known to decrease with increasing temperature.

Antineoplastic Agents↗
PubMed1994

Gallium-67/gallium-68-[DFO]-octreotide--a potential radiopharmaceutical for PET imaging of somatostatin receptor-positive tumors: synthesis and radiolabeling in vitro and preliminary in vivo studies.

UNLABELLED: When labeled with gamma-emitting radionuclides, somatostatin analogs have the potential to localize somatostatin receptor-positive tumors using gamma camera scintigraphy. We present a somatostatin analog, [DFO]-octreotide (SDZ 216-927), that comprises desferrioxamine B coupled to octreotide via a succinyl linker. This conjugate can be labeled with either 67Ga for gamma scintigraphy or 68Ga for PET imaging. The 67Ga-labeled conjugate is stable in vitro to autoradiolysis over a 24-hr period. METHODS: Rats bearing a somatostatin receptor-positive pancreatic islet cell tumor were injected with 20 MBq of 67Ga[DFO]-octreotide (33 GBq 67Ga/mumole). RESULTS: After 1 hr, the accumulation of 67Ga[DFO]-octreotide was 0.38 +/- 0.08 %ID/g and the tumor-to-nontumor ratios for blood, muscle, liver and intestine were 2.5, 7.4, 1.9 and 1.6, respectively. PET studies with 68Ga[DFO]-octreotide recorded a very rapid accumulation at the tumor and a subsequent residence half-life of about 6 hr. CONCLUSION: Gallium-68-[DFO]-octreotide can be used in PET studies to diagnose receptor-positive tumors such as gastroenteropancreatic, small-cell lung and breast tumors.

Animals↗
PubMed1997

Sonodynamic toxicity of gallium-porphyrin analogue ATX-70 in human leukemia cells.

Low concentrations (> or = 1 microM) of the gallium-porphyrin analogue ATX-70 significantly enhanced cellular toxicity in human leukemia HL-525 cells exposed to 50 kHz ultrasound. The mechanism of this ATX-70-dependent sonosensitization is unknown, but we have established the requirement of extracellular localization of ATX-70 molecules for sonosensitization. Short-lived toxic intermediates produced from ATX-70 by ultrasound are implicated in the mechanism, since no cytotoxicity was found when medium containing ATX-70 was sonicated and subsequently added to the cells. However, we were unable to demonstrate the existence of radical intermediates by EPR spin trapping with the nitroso spin trap, DBNBS, and ATX-70-dependent sonotoxicity could not be ameliorated by the addition of up to 70 mM POBN and DMPO spin traps during ultrasound exposure.

Cell Death↗
PubMedDate not supplied

Effects of lining materials on shear bond strength of amalgam and gallium alloy restorations.

In this in vitro study, where alloys were condensed into unset paste lining materials, shear bond strengths were significantly greater than with the unlined controls. The use of varnish or Paama 2 linings did not significantly increase the shear bond strength of amalgam or gallium alloy restorations. The use of Vitrabond, Vitremer, or Resinomer liners significantly increased the shear bond strength compared to unlined restorations. Permite C restorations lined with Resinomer all showed cohesive failure within the mixed alloy/ liner. Of the unlined restorations, Permite C had significantly higher shear bond strength than Lojic Plus. The experimental method used in the present study proved to be suitable for quantitative comparison of the shear bond strength of different dental materials.

Analysis of Variance↗
PubMedDate not supplied

Bonding of amalgam and a gallium alloy to bovine dentin.

The shear bond strengths of an amalgam (Permite C) and a gallium alloy (Galloy) to dentin, mediated by four dentin adhesives (Super-Bond D-Liner, Super-Bond D-Liner II, Paama 2, and Panavia 21), were investigated. Flat labial dentin surfaces were prepared from bovine lower incisor teeth. A 3 mm-in-diameter area of dentin was bonded according to each manufacturer's directions before placement of Permite C or Galloy. The bonds were stressed in shear at a crosshead speed of 1 mm/min. The mean shear bond strengths were analyzed using one-way ANOVA and Student's t-test, and fracture modes were assessed under X20 magnification and analyzed using Kruskal-Wallis and Mann-Whitney U tests. Scanning electron micrographs were taken of the bond interface of separate samples. The results showed no significant difference among the bond strengths of Super-Bond D-Liner (2.79 MPa, 2.69 MPa), Super-Bond D-Liner II (3.41 MPa, 2.65 MPa), and Paama 2 (0.70 MPa, 0.50 MPa) bonded to Permite C and Galloy (respective values in parentheses); however, Panavia gave a significantly better bond with Permite C (0.42 MPa) than with Galloy (0 MPa). Super-Bond D-Liner and Super-Bond D-Liner II gave stronger bonds than Paama 2 and Panavia with both Permite C and Galloy. For each dentin adhesive, there was no difference in fracture mode between Permite C and Galloy. It was concluded that, since all bond strengths were very low, none of the dentin adhesives tested would enhance the clinical retention of Permite C or Galloy. However, although the use of Paama 2 with Galloy was originally recommended by the manufacturer for dentin sealing purposes, no adhesion was claimed.

Animals↗
PubMedDate not supplied

Effects of sealers and liners on marginal leakage of amalgam and gallium alloy restorations.

In an in vitro study, the use of sealers and liners (Fuji varnish, Vitrabond, Vitremer, Paama 2, All-Bond 2, or Resinomer) significantly reduced the amount of marginal leakage around amalgam (Permite C or Lojic Plus) and gallium (Galloy) alloy restorations. This reduction in marginal leakage was produced by all sealers and liners tested, and there were no statistically significant differences between these materials. Unlined restorations of Permite C had significantly less marginal leakage than Galloy or Lojic Plus. Unlined Lojic Plus restorations had the greatest amount of marginal leakage. The experimental method used in the present study proved to be suitable for quantitative comparison of marginal leakage of different dental materials.

Analysis of Variance↗