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At least 235 records · Page 13Linked to original sources
PubMed1991

The role of gallium-67 imaging in the detection of foci in recent cases of fever of unknown origin.

We have assembled data from patients with fever of unknown origin who underwent gallium scintigraphy during the past 5 years in order to obtain a more current sampling of patients, and evaluated the role of gallium scintigraphy retrospectively. Of the 36 patients studied, gallium scintigraphy was positive and contributed to the detection of the foci or fever origins in 17 (47.2%). The ratio of neoplastic diseases with myeloproliferative and with lymphoproliferative disorders was relatively high compared with previous reports. However, gallium scintigraphy did not contribute to the diagnosis of collagen disease. With the ability to detect both inflammatory and neoplastic lesions, gallium scintigraphy was useful in detecting the foci of fevers of unknown origin.

Adolescent↗
PubMed1980

Gallium-67 citrate scanning for noninvasive detection of inflammation in pericardial diseases.

The treatment of acute nonspecific pericarditis is controversial. No study is available that confirms the efficacy of the administration of corticosteroids or nonsteroid anti-inflammatory agents in this condition. There is no reliable invasive marker for pericardial inflammation, because echocardigraphy demonstrates only the presence of fluid. In four patients with pericarditis, gallium-67 citrate scanning was performed, and the isotope was localized to the cardiac silhouette in all. In one patient with effusion the gallium scan was positive and then reverted to negative with corticosteroid therapy. In another, the gallium scan remained positive despite resolution of the pericardial effusion with corticosteroid therapy. This patient eventually required pericardial stripping. Pericardial localization of gallium was useful in detecting the cause of fever in a patient after aortocoronary bypass grafting and in detecting pericardial involvement in a patient with multisystem viral disease. Pericardial localization of gallium-67 may be diagnostically useful and may provide a proper control for the study of the efficacy of corticosteroids versus nonsteroid anti-inflammatory agents in pericarditis.

Adolescent↗
PubMed1980

Gallium-67 scanning: limited usefulness in staging patients with non-Hodgkin's lymphoma.

The records of 122 patients with non-Hodgkin's lymphoma were reviewed, and the findings of the gallium scan analyzed. The scans of 93 patients were reread without knowledge of the previous readings. Two nuclear medicine physicians agreed with the original readings in 70 per cent of the cases and with each other in 89 per cent of the cases. When the data are analyzed case by case, 52 per cent true positive, 13 per cent false positive and 34 per cent false negative scans were found with only 17 per cent of the scans locating disease not found by routine physical examination and roentgenograms. Looking at individual sites of disease, the gallium scan yields an over-all detection of diseased sites of 18.5 per cent, with 72 per cent of all sites being correctly classified as positive or negative. The diffuse histiocytic, mixed and undifferentiated histologies were detected more accurately than all others, with mediastinal and extranodal sites being identified more frequently than any nodal site. The gallium scan revealed a site of disease which advanced the clinical stage in only one of 122 patients (upstaged). Only one of 122 patients was upstaged as a result of gallium scanning. These data suggest that gallium scanning may not be cost effective in the routine staging of patients with non-Hodgkin's lymphoma.

Cost-Benefit Analysis↗
PubMed1984

In vitro solubility and in vivo toxicity of gallium arsenide.

The in vitro solubilities of gallium arsenide (GaAs) and its metal oxides were arsenic(III) oxide greater than GaAs much greater than gallium(III) oxide. GaAs dissolution was also dependent upon the type and concentration of buffer anion. The amount of arsenic dissolved in 12 hr by various aqueous media was 0.2 M phosphate buffer greater than or equal to 0.1 M phosphate buffer greater than Krebs-Hensleit buffer greater than distilled H2O greater than HCl-KCl buffer. GaAs was apparently soluble under in vivo conditions. Blood arsenic concentrations in rats 14 days after intratracheal instillation of 10, 30, or 100 mg/kg GaAs were 5.5, 14.3, and 53.6 micrograms/ml, respectively; gallium was not detected at any doses. An increase in lung wet weight at 14 days was dose dependent with these organs retaining 17 to 42% of the dose as gallium or arsenic. Excretion of gallium and arsenic was limited to the feces. Urinary porphyrin concentrations and body weight, monitored as indices of toxicity, were significantly altered over the 14-day study. The analysis of porphyrins revealed that uroporphyrin replaced coproporphyrin as the primary urinary metabolite. Rats receiving 10, 100, or 1000 mg/kg GaAs po exhibited similar signs of toxicity. Blood arsenic concentrations at 14 days were 3.5, 6.8, and 17.6 micrograms/ml, respectively. Porphyria was increased, and body weight was decreased at 1000 mg/kg GaAs. These values were equivalent to those obtained with an intratracheal dose of 10 to 30 mg/kg GaAs. Our results showed that pulmonary and po exposure to GaAs resulted in systemic arsenic intoxication. The finding that urinary uroporphyrin concentrations were greater than coproporphyrin concentrations may serve as a sensitive indicator for GaAs exposure.

Animals↗
PubMed1983

Localization of gallium in tumor cells. Electron microscopy, electron probe microanalysis and analytical ion microscopy.

The incorporation of gallium in tumor cells in vitro and in solid tumors was studied with electron microscopy and two microanalytical techniques. It was thus possible (1) to directly prove that gallium is concentrated in lysosomes of tumor cells; (2) to demonstrate that in these lysosomes, gallium is precipitated with phosphorus; and (3) to propose a mechanism of gallium concentration in tumor cells; in this mechanism, the accumulation of gallium as phosphate salts in lysosomes is directly related to the acid phosphatase activity of these organelles.

Animals↗
PubMed1991

Bone particles from gallium-treated rats are resistant to resorption in vivo.

Gallium nitrate is a clinically effective agent for the treatment of cancer related hypercalcemia. The mechanism of action of this agent was investigated following development of a quantitative in vivo bone resorption assay modified from the method of Glowacki. In a preliminary study, the time course of resorption of 50 mg subcutaneous implants of bone powder in growing rats was followed by chemical analysis of mineral (ash and Ca) contents, enzymatic and histochemical assay of tartrate resistant acid phosphatase (TRAP) activity, and image analysis of changes in particle size using von Kossa stained sections. Day 21 was chosen as a single time point for the comparison of the extent of resorption of gallium-containing and control bone particles. Resorption of bone particles containing 0.39 micrograms Ga/mg bone was significantly inhibited relative to control particles. Mineral content (6.7 vs. 3.6 mg), Ca content (1.72 vs. 1.37 mg), and the percentage of the field covered by bone particles (12 vs. 9%) were greater in the animals which received gallium-containing bone particles. Similarly, the number of osteoclast-like cells and the TRAP activity in the gallium-containing bone particle implants at 21 days were increased relative to controls. These data indicate that gallium incorporation into bone matrix confers resistance to resorption.

Acid Phosphatase↗
PubMed2006

The influence of gallium and other metal ions on the uptake of non-transferrin-bound iron by rat hepatocytes.

BACKGROUND: Under conditions of iron overload non-transferrin-bound iron (NTBI) occurs in the circulation and is mainly cleared by the liver. Beside iron, gallium and aluminum enhance accumulation of NTBI. We try to characterize the mechanism and metal-mediated regulation of NTBI uptake using cultivated primary rat hepatocytes. METHODS: Hepatocytes from rat liver were incubated with 0.1 mg/ml transferrin (as control), with ferric ammonium citrate or other di- and trivalent metal salts and the uptake of (55)Fe-labeled Fe-diethylene triammine pentaacetate was measured. RESULTS: Uptake rates for iron increased from 0.3 to 2.1 pmol/mg protein per min in cells preincubated for 5 hours with 300 microM ferric ammonium citrate, to 1.7 pmol/mg protein per min with gallium and to 1.2 pmol/mg protein per min with aluminum. Maximal stimulation was obtained with 300 microM iron and 600 microM gallium. Preincubation with divalent metals was ineffective. NTBI uptake was specific for iron, partly inhibited by gallium citrate, diferric transferrin and completely inhibited by apotransferrin in control and gallium-treated cells. In iron-loaded cells, inhibition of NTBI uptake by diferric transferrin completely disappeared within 2 hours. CONCLUSIONS: These experiments show that hepatocytes do respond to the presence of trivalent metals by an increased transport capacity to sequester these ions. The metals seem to have at least partly different mechanisms of transport stimulation.

Animals↗
PubMed1978

The use of gallium-67 in pulmonary disorders.

Imaging of the chest cage with gallium-67 (67Ga) citrate is relatively easier to perform and interpret than imaging of the abdomen, because normally pulmonary concentration is low after 48 hr and physiologic accumulation in bones and breast can be recognized by its distribution. Modern scintillation detectors, particularly large field cameras with multiple pulse-height analyzers, give substantially better gallium images than those available in the past. Because of the nonspecific affinity of gallium through neoplastic and inflammatory processes, its value in the differential diagnosis of pulmonary diseases is limited. However, based on the literature and our own observations in over 1100 patients with established diagnosis of a variety of pulmonary diseases, we feel that the judicious use of 67Ga in selected patients is helpful in answering specific questions. These include preoperative evaluation of hilar and mediastinal involvement in pulmonary neoplasms, differential diagnosis of pulmonary infarctions and bacterial pneumonias, evaluation of pulmonary infiltrates regarding infectious etiology, follow-up of sarcoidosis on corticosteroid treatment, assessment of inflammatory activity in interstitial fibrosis and, in selected cases, early detection of neoplastic and inflammatory diseases before radiography becomes abnormal, such as diffuse carcinomatosis and Pneumocystis carinii infection. Potential large-scale application of pulmonary gallium imaging could be found in the screening of subjects exposed occupationally to noxious dust and in long-term serial follow-up of pulmonary tuberculosis patients for treatment response and reactivation. However, it remains to be seen whether gallium imaging statistically provides essential additional information in these indications when compared to cheaper conventional techniques.

Diagnosis, Differential↗
PubMed1984

Scintigraphic evaluation of the painful prosthetic joint: a comparison of gallium-67 citrate and indium-111 labelled leucocyte imaging.

The radiopharmaceuticals gallium-67 and indium-111 labelled leucocytes have been compared in 15 patients with a painful joint prosthesis in an attempt to identify those patients with periprosthetic infection. Gallium-67 images were abnormal in five out of six patients with periprosthetic infection and normal in seven out of nine without evidence of infection. Indium-111 leucocyte images were abnormal in three out of six patients with infection and normal in all nine patients without infection. Indium-111 labelled leucocyte imaging is technically more difficult to perform than gallium-67 imaging. This, combined with the higher sensitivity of gallium-67 imaging for infection around a prosthetic joint, leads us to conclude that gallium-67 imaging is superior to indium-111 leucocyte imaging in identifying infection as a cause of a painful prosthetic joint.

Adult↗
PubMed2003

Effects of gallium on common carp (Cyprinus carpio): acute test, serum biochemistry, and erythrocyte morphology.

Gallium (Ga) is one of the intermetallic elements that are increasingly being used in making high-speed semiconductors such as gallium arsenide. The purposes of this study were to investigate the effects of gallium on acute toxicity, on serum biochemical variables as well as on erythrocyte morphological changes in the blood stream of common carp (Cyprinus carpio). Median lethal concentrations were determined in acute tests. The 96-h LC50 value was 19.78 (18.49-21.16) mgl(-1). Common carp were exposed to different gallium concentrations (2.0, 4.0, and 8.0 mgl(-1)) for 28 days in laboratory toxicity tests. Means of the measured serum biochemistry parameters (including glucose, blood urea nitrogen, creatinine, cholesterol, and triglyceride) of these exposed groups significantly differed from those of the untreated group. Deformation of erythrocytes suggest disturbance of respiration as an additional indicator of Ga exposure. Our results suggest that 2.0 mgl(-1) is proposed as a biologically safe concentration which can be used for establishing tentative water quality criteria concerning of same size common carp. In addition, serum biochemical parameters as well as erythrocyte morphological changes are promising clinical diagnostic tools for assessing the effects of gallium compounds on common carp.

Animals↗
PubMed2001

Shear strengths of a gallium alloy bonded to human enamel following nine different surface treatments.

OBJECTIVE: Gallium and indium-containing alloys have demonstrated an ability to wet and bond to many types of materials including enamel. The purpose of this study was to evaluate and compare the bond strengths of a gallium-and-indium-containing alloy and a dental amalgam to human enamel surfaces. METHOD: A flat enamel bonding surface was created by slicing recently extracted human molars with a 180-grit diamond wheel. Cylinders of amalgam or a gallium-indium alloy were bonded to the as-cut surfaces or to as-cut surfaces that had been pumiced, air-abraded or acid-etched for various times. Before testing, samples were stored under different conditions (100% humidity, immersed in water, thermocycled). The shear-bond strength was determined using a crosshead speed of 0.1 mm x min(-1). Sample size was 10. Data was subjected to ANOVA and a post-hoc Tukey's test. RESULTS: The bond strength of amalgam to enamel was zero. The bond strength of the gallium-indium alloy ranged between 6.5 MPa (10s etch with 10% phosphoric acid) and 4.2 MPa (pumiced enamel). Acid-etching significantly increased the bond strength (P>0.0001) The bond strength was not significantly affected by the type of mechanical surface preparation, storage conditions, thermocycling, etching times or acid concentrations. SIGNIFICANCE: Bonding, particularly chemical bonding, suggests a greater potential for better wetting and therefore better sealing of a cavity. Since microleakage of restorations is one of the principal causes of restoration failure, materials that can bond may in turn posses enhanced resistance to microleakage and ultimately, resistance to restoration failure. The gallium-indium alloy evaluated in this study may be such an alloy.

Acid Etching, Dental↗
PubMed2001

A comparison of the mechanical properties of a gallium-based alloy with a spherical high-copper amalgam.

OBJECTIVES: The aim of the present study was to investigate how the mechanical properties of a palladium free gallium-based alloy (Galloy) compare with a leading spherical high-copper amalgam (Tytin). METHODS: Cylindrical specimens were mechanically condensed, according to the ISO 1559:1986 standard, to measure compressive strength, Vickers hardness, static creep and dimensional change on setting. Disc and beam shaped specimens were manually prepared to assess the diametral tensile and flexural strengths of the investigated alloys. RESULTS: The mean hardness, 1h compressive fracture strength, 24 h diametral tensile and 24h flexural strengths of Galloy were significantly lower (P<0.001) than Tytin. No significant differences in modulus of elasticity, creep, dimensional change on setting, 24 and 168 h compressive fracture strength for the two alloys were identified. SIGNIFICANCE: The significant reduction in the 1 h mean compressive fracture strength and hardness identified for Galloy compared with Tytin possibly indicate a slower setting reaction in the gallium-based alloy. Manual condensation of the gallium-based alloy produced specimens with inferior mechanical properties possibly due to the increased likelihood of introducing voids within the test specimens. Previous reports indicating poor corrosion resistance and moisture sensitivity of gallium-based alloys highlight the need for further research to investigate the effect of the oral environment on the gallium-based alloy.

Compressive Strength↗
PubMed1988

Gallium 67 scintigraphy in glomerular disease.

To evaluate the diagnostic usefulness of gallium 67 scintigraphy in glomerular disease, 45 patients with various glomerulopathies, excluding lupus nephritis and renal vasculitis, were studied. Persistent renal visualization 48 hours after the gallium injection, a positive scintigram, was graded as + (less than), ++ (equal to), and +++ (greater than) the hepatic uptake. Positive scintigrams were seen in ten of 16 cases of focal segmental glomerulosclerosis, six of 11 cases of proliferative glomerulonephritis, and one case of minimal change, and one of two cases of membranous nephropathy; also in three of six cases of sickle glomerulopathy, two cases of diabetic neuropathy, one of two cases of amyloidosis, and one case of mild chronic allograft rejection. The 25 patients with positive scans were younger than the 20 with negative scans (31 +/- 12 v 42 +/- 17 years; P less than 0.01), and exhibited greater proteinuria (8.19 +/- 7.96 v 2.9 +/- 2.3 S/d; P less than 0.01) and lower serum creatinine values (2 +/- 2 v 4.1 +/- 2.8 mg/dL; P less than 0.01). The amount of proteinuria correlated directly with the intensity grade of the gallium image (P less than 0.02), but there was no correlation between the biopsy diagnosis and the outcome of the gallium scan. It was concluded that gallium scintigraphy is not useful in the differential diagnosis of the glomerular diseases under discussion. Younger patients with good renal function and heavy proteinuria are likely to have a positive renal scintigram regardless of the underlying glomerulopathy.

Adult↗
PubMed1999

A receptor-based bioassay for quantitative detection of gallium.

The detection of gallium in biological samples is required due to its role in the diagnosis of tumor and for possible treatment of malignancies. However, the use of purely instrumental techniques is unsuitable for detection of low levels of gallium in biological matrixes. We have synthesized new protein conjugates based on 4-(2-pyridylazo) ligands. The conjugates were successfully employed for the detection of gallium in biological matrixes using a nonantibody-based sandwich assay format. The recovery level obtained was between 97 and 101.3 with a relative standard deviation of less than 5%. The assay resulted in a detection limit of 5 x 10(-8) M and a remarkable selectivity for gallium(III) relative to other metals investigated. The new method provided adequate accuracy for gallium applicable for animal physiology and clinical toxicology.

Biological Assay↗
PubMed2004

FDG-PET is superior to gallium scintigraphy in staging and more sensitive in the follow-up of patients with de novo Hodgkin lymphoma: a blinded comparison.

Accurate staging of Hodgkin lymphoma (HD) allows for minimization of therapy and reduction of long-term toxicities. The present study prospectively compares FDG-PET with gallium/SPECT scintigraphy at time of diagnosis and in follow-up of 36 patients with HD. Prior to therapy, whole body FDG-PET and gallium/SPECT were performed. Follow-up scans were obtained after 3 cycles of chemotherapy (n = 22), and at the end of chemotherapy (n = 32). Two nuclear medicine physicians independently interpreted scans in blinded and random order and a consensus was obtained. Baseline scans revealed a greater number of supradiaphragmatic disease sites detected by PET, and 5 patients had splenic involvement on PET not noted by gallium (P = 0.05); 3 patients were upstaged on PET. Midway through therapy, 5 patients had positive PET (4 of whom relapsed), and 3 had positive gallium (1 relapsed). At conclusion of chemotherapy, 8 patients had a positive PET (4 relapsed) and 3 had a positive gallium (2 relapsed). In conclusion, diagnostic PET and gallium are largely concordant, with the exception of unique detection of splenic disease by PET. However, more patients have persistently positive PET at the end of chemotherapy compared with gallium (P = 0.04), although only half of these patients have relapsed.

Adolescent↗
PubMed2005

Separation of gallium and arsenic in wafer grinding extraction solution using a supported liquid membrane that contains PC88A as a carrier.

Wafer grinding extraction solution was passed through a supported liquid membrane (SLM) that contained PC88A (2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester) as a carrier, to separate gallium from arsenic by selective permeation. The SLM separation process was conducted under various conditions. The kind of membrane supporter, the pH of the feed, the feed concentration, and the HCl content in the strip governed the concentration of gallium and arsenic in the strip phase. The conditions determined as optimal in the laboratory test were used to perform the pilot test. Well separation between gallium and arsenic was performed in both laboratory and pilot tests. Hydrophobic membrane polytetrafluoroethylene (PTFE) with 0.2 microm pores was the best of three membrane supporters. The most efficient separation was obtained using an acidic feed (pH at 1.8) with 1000 ppm gallium. Over a 12-h period of stripping, the striped Ga concentration increased with the HCl concentration from 0.5 to 2.0 M and then leveled off. The recovery rate in the pilot test exceeded that on the laboratory scale because the membrane area was greater. The pilot test yielded a high recovery percentage of gallium (at 91%) and a low recovery of arsenic (merely 1.3 ppm) in the strip over 72 h.

Arsenic↗
PubMed2000

Gallium diffusion in human root dentin: quantitative measurements by pulsed Nd:YAG laser ablation combined with an inductively coupled plasma mass spectrometer.

OBJECTIVE: The purpose of this work was to determine if gallium nitrate placed in human root canals would diffuse across root dentin and reach concentrations high enough to inhibit osteoclasts (approximately 10(-4) M). BACKGROUND DATA: External root resorption by osteoclasts is a common sequela of dental trauma. If not detected and treated, it can lead to the loss of a tooth. Gallium has recently been reported to inhibit osteoclastic resorption in vitro. METHODS: Roots were cleaned and shaped using standard endodontic procedures and the tips sealed with cyanoacrylate cement. The root canal space was filled with an aqueous solution of 1.0 M gallium nitrate chelated with 1.0 M sodium citrate buffer (pH 7.2). The roots were then sectioned longitudinally into two equal halves. Each half was fixed to a translation stage that moved at a constant rate beneath a frequency-quadrupled Nd-YAG laser (266 nm) laser that was used to sample the concentration of 43Ca, 69Ga, and 71Ga by laser ablation across the thickness of root dentin to the periodontal surface. The plume of ablated dentin was swept into an inductively heated plasma chamber by argon gas and hence into a mass spectrometer. RESULTS: Quantitative analyses of the distribution of gallium showed it was highest adjacent to the root canal space and fell as more peripheral sites were sampled but then rose slightly at the external boundary of the root which is covered with a thin layer of atubular cementum. CONCLUSIONS: Even the lowest concentrations of gallium found in peripheral root dentin exceeded the 10(-4) M concentration required to inhibit osteoclastic activity. This simple endodontic treatment should undergo clinical trials to determine its efficacy in vivo. The laser ablation, inductively coupled mass spectrometry method is a powerful analytic tool for measuring spatial distribution of materials in mineralized tissues.

Dental Pulp Cavity↗
PubMed1986

Gallium scintigraphy in a case of septic cavernous sinus thrombosis.

Septic cavernous sinus thrombosis, a relatively uncommon disease entity, frequently can be fatal. Early diagnosis is imperative in order that appropriate treatment be instituted. A 59-year-old woman who was admitted to our institution with complaints of diplopia, blurred vision and fevers that developed following a tooth extraction is presented. Initial CT and lumbar puncture on the day of admission were totally normal. A repeat CT performed 48 hours after admission, on the same day as gallium imaging, demonstrated findings consistent with cavernous sinus thrombosis. Gallium imaging demonstrated intense uptake in the left cavernous sinus and left orbit as well as moderately increased activity in the right cavernous sinus and orbit, confirming infection. The patient was treated with antibiotics, and repeat CT and gallium imaging were performed ten days later, both of which demonstrated near total resolution of the disease process. Conceivably, if gallium imaging had been initiated on the day of admission it may have been the first study to demonstrate an infectious process in the cavernous sinus. Gallium imaging should be considered as a diagnostic tool in the noninvasive workup of this entity.

Bacterial Infections↗