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 631 records · Page 35Linked to original sources
PubMed2006

Ferredoxin/ferredoxin-thioredoxin reductase complex: Complete NMR mapping of the interaction site on ferredoxin by gallium substitution.

The reduction of ferredoxin-thioredoxin reductase (FTR) by plant-type ferredoxin plays an important role in redox regulation in plants and cyanobacteria. Nuclear magnetic resonance (NMR) was used to map the binding sites on Synechocystis ferredoxin for FTR. A gallium-substituted structural analog of this [2Fe-2S] ferredoxin was obtained by reconstituting the apoprotein in a refolding buffer containing gallium. For the first time, the complete interaction interface of a [2Fe-2S] ferredoxin with a target enzyme has been mapped by NMR chemical shift perturbation with this diamagnetic structural analog.

Amino Acid Sequence↗
PubMed2005

Synthesis and characterization of dual function vanadyl, gallium and indium curcumin complexes for medicinal applications.

Novel bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione (curcumin) complexes with the formula, ML(3), where M is Ga(III) or In(III), or of the formula, ML(2) where M is [VO](2+), have been synthesized and characterized by mass spectrometry, infrared and absorption spectroscopies, and elemental analysis. A new ligand, bis[4-acetyl-3-hydroxyphenyl]-1,6-heptadiene-3,5-dione (diacetylbisdemethoxycurcumin, DABC) was similarly characterized; an X-ray structure analysis was performed. Vanadyl complexes tested in an acute i.p. testing protocol in STZ-diabetic rats showed a lack of insulin enhancing potential. Vanadyl complexes were, however, more cytotoxic than were the ligands alone in standard MTT (3-[4,5-dimethylthiazole-2-yl]ate, -2,5-diphenyl-tetrazolium bromide) cytotoxicity testing, using mouse lymphoma cells. With the exception of DABC, that was not different from VO(DABC)(2), the complexes were not significantly different from one another, with IC(50) values in the 5-10 microM range. Gallium and indium curcumin complexes had IC(50) values in the same 5-10 microM range; whereas Ga(DAC)(3) and In(DAC)(3) (where DAC=diacetylcurcumin) were much less cytotoxic (IC(50)=20-30 microM). Antioxidant capacity was decreased in VO(DAC)(2), Ga(DAC)(3), and In(DAC)(3), compared to vanadyl, gallium and indium curcumin, corroborating the importance of curcumin's free phenolic OH groups for scavenging oxidants, and correlated with reduced cytotoxic potential.

Animals↗
PubMed2003

The metabolism of inorganic arsenic oxides, gallium arsenide, and arsine: a toxicochemical review.

The aim of this review is to compare the metabolism, chemistry, and biological effects to determine if either of the industrial arsenicals (arsine and gallium arsenide) act like the environmental arsenic oxides (arsenite and arsenate). The metabolism of the arsenic oxides has been extensively investigated in the past 4 years and the differences between the arsenic metabolites in the oxidation states +III versus +V and with one or two methyl groups added have shown increased importance. The arsenic oxide metabolism has been compared with arsine (oxidation state -III) and arsenide (oxidation state between 0 to -III). The different metabolites appear to have different strengths of reaction for binding arsenic (III) to thiol groups, their oxidation-reduction reactions and their forming an arsenic-carbon bond. It is unclear if the differences in parameters such as the presence or absence of methyl metabolites, the rates of AsV reduction compared to the rates of AsIII oxidation, or the competition of phosphate and arsenate for cellular uptake are large enough to change biological effects. The arsine rate of decomposition, products of metabolism, target organ of toxic action, and protein binding appeared to support an oxidized arsenic metabolite. This arsine metabolite was very different from anything made by the arsenic oxides. The gallium arsenide had a lower solubility than any other arsenic compound and it had a disproportionate intensity of lung damage to suggest that the GaAs had a site of contact interaction and that oxidation reactions were important in its toxicity. The urinary metabolites after GaAs exposure were the same as excreted by arsenic oxides but the chemical compounds responsible for the toxic effects of GaAs are different from the arsenic oxides. The review concludes that there is insufficient evidence to equate the different arsenic compounds. There are several differences in the toxicity of the arsenic compounds that will require substantial research.

Animals↗
PubMed1976

Gallium-67 tumor scanning.

Since its introduction in 1969, 67Ga has become the most widely employed tumor-scanning agent in nuclear medicine. While 67Ga is far from being the ideal tumor-scanning agent, it remains the best available isotope for this purpose. Gallium-67-citrate has been found to be of value in the staging and reevaluation of lymphomas as well as in detecting the extent and recurrence of lung tumors, breast tumors, malignant melanomas, testicular tumors, brain tumors, and malignant lesions involving the liver. In order to obtain maximum diagnostic value from gallium scanning, several technical factors have to be taken into consideration as well as an understanding of the nature of "false-positive" scans.

Acute Disease↗
PubMed1978

Gallium-67 imaging in the management of Hodgkin's disease and other malignant lymphomas.

Gallium-67 imaging is useful in the management of patients with malignant lymphoma, despite its obvious limitations. Data currently in the literature regarding the detectability of sites of lymphoma by 67Ga imaging should be regarded as representing the minimum that can be expected from the method, since all reported series are based on outmoded imaging techniques. The detectability of disease sites appears to vary with tumor histology and anatomic location. Gallium-67 imaging is most useful in following patients after treatment. However, it may justifiably play an important role in the initial staging of lymphoma if the prior probability of disease in the abdomen is low. Lymphoma in abdominal lymph node sites is at least as detectable by 67Ga imaging as by lymphangiography.

Abdominal Neoplasms↗
PubMed1978

Gallium-67 imaging in abdominal disease.

Gallium-67 imaging is useful for detecting sites of intra-abdominal inflammation, including subphrenic abscesses, postoperative infection, pyelonephritis or perinephric abscesses, and peritonitis. Positive images may be obtained within several hours of injection, but are more reliable at 24 hr. The results may be used to guide ultrasound or computed tomography studies, which give a detailed anatomic picture of the abscess. Gallium-67 imaging has also been used to detect abdominal neoplasms, but results are less impressive. Abdominal lymphoma is detected in just over 50% of sites. Gastrointestinal, renal, and gynecologic neoplasms are detected even less frequently. However, 67Ga is useful for detecting recurrence of 67Ga-avid neoplasms, and has been reliable in detecting hepatomas and nodal spread of seminoma. When used selectively in patients with neoplastic disease and suspected abscesses, 67Ga is an effective method for diagnosing abdominal disease.

Abdomen↗
PubMed1984

The role of gallium-67 in the clinical evaluation of cancer.

This review is based primarily on historic data, and it examines the indications for and limitations of gallium-67 scanning in the evaluation of patients with neoplasms. The use of gallium-67 scans is discussed according to tumor type, and data from the most representative and comprehensive studies are included. The results described, some of which were obtained primarily with older imaging techniques, should be regarded as representing the minimum that can be expected from application of this imaging procedure.

Adult↗
PubMed1989

Bronchoalveolar lavage analysis, gallium-67 lung scanning and soluble interleukin-2 receptor levels in asbestos exposure.

This study examined different markers of lung immunologic and inflammatory responses to previous asbestos exposure. We performed bronchoalveolar lavage (BAL) and gallium-67 (67Ga) lung scans and measured serum and BAL soluble interleukin-2 receptor (IL-2R) and angiotensin-converting enzyme (SACE) levels in 32 subjects with a history of significant asbestos exposure, 14 without (EXP) and 18 with (ASB) radiographic evidence of asbestosis. BAL analysis revealed increases in neutrophils in both ASB and EXP when compared to controls (P less than 0.01), which persisted after adjustment for smoking category. Although significant abnormalities of macrophage and total lymphocyte profiles were not found in the study population, lymphocyte subpopulation analysis revealed elevation of BAL T4/T8 ratios in the entire study group (ASB + EXP) when compared to controls (P less than 0.05), independent of smoking category. 67Ga lung scan activity was increased in 56% of ASB and in 36% of EXP: no correlations between positive scans and different radiological and functional parameters could be found. There was no significant elevation of mean SACE, serum, or BAL IL-2R levels in any of the study categories. These data suggest that asbestos exposure may be associated with parenchymal inflammation, even in the absence of clinical criteria for asbestosis. Abnormalities of gallium uptake and of BAL analysis reflect the clinically inapparent inflammation. The increased BAL T4/T8 ratios observed suggest that abnormal local pulmonary immunoregulation may play a role in the pathogenesis of asbestos-related lung diseases.

Adult↗
PubMed1999

Gallium nitrate suppresses the production of nitric oxide and liver damage in a murine model of LPS-induced septic shock.

The efficacy of gallium (Ga) nitrate was examined in a murine model of sepsis. Male Balb/c mice (6-8 weeks) were randomized into 3 groups: 1) vehicle-treated controls 2) mice with sepsis induced by treatment with 0.3 mg i.v. of Propionibacterium acnes followed one week later by 0.01 microg lipopolysaccharide (LPS) and 10 mg of D-galactosamine (GalN) 3) mice with sepsis injected with 45 mg/kg s.c. of gallium nitrate (calculated as elemental Ga) 24 hours prior to LPS/GalN. Two hours after LPS/GalN or vehicle, plasma concentrations of tumor necrosis factor (TNF-alpha) in groups 1, 2 and 3 were 54+/-31 (n=6), 21,390+/-5139 (n=4), and 21,909+/-943 (n=5) pg/ml, respectively. After 6 hours, plasma concentrations of gamma interferon (IFN-gamma) were <10 (n=8), 4771+/-1078 (n=6), and 1622+/-531 (n=15) pg/ml, respectively, and of nitrate/nitrite (products of nitric oxide) were 64+/-8 (n=7), 146+/-18 (n=8), and 57+/-8 (n=15) microM. At 18 hours, serum chemistries were; SGOT 171+/-46 (n=13), 10,986+/-3062 (n=7), and 1078+/-549 (n=8) IU/L; SGPT 165+/-59, 17,214+/-4340, and 2088+/-1097 IU/L; and total bilirubin 0.2+/-0.0, 0.9+/-0.4, and 0.2+/-0.0 mg/dl for groups 1, 2, and 3 respectively. Blinded histologic evaluation of livers at 18 hours revealed inflammatory infiltrate scores (x [range], 0=none, 1=minimal, 2=mild, 3=moderate, and 4=severe) of 0.1 [0-1] (n=8), 3.0 [2-4] (n=15), and 2.0 [0-3] (n=10), and necrosis scores of 0.0, 2.8 [0-4], and 0.9 [0-4]. Although Ga did not affect production of TNF-alpha, it ameliorated hepatocellular injury and protected against necrosis. Based on this model of sepsis, Ga may have a role in treating the human disease.

Animals↗
PubMed2001

Diagnosis and treatment of pyogenic psoas abscess in diabetic patients: usefulness of computed tomography and gallium-67 scanning.

OBJECTIVES: To examine retrospectively the clinical presentations, microbiologic characteristics, and treatment outcomes of psoas abscess in patients with diabetes mellitus (DM) and to assess the usefulness of computed tomography and gallium-67 scanning in its early diagnosis. METHODS: During a 9-year period, psoas abscesses in patients with DM were collected at a medical center. The clinical history and associated etiologic factors, microbiologic results, clinical outcomes, and hospitalization days were recorded. The use of imaging in the diagnosis of psoas abscess and other concomitant infectious lesions was also studied. RESULTS: Fifteen patients with DM and psoas abscess (13 women and 2 men; mean age 58.7 +/- 9.0 years) were found. The most frequent symptom was fever (12 of 15). Of the six different microorganisms that grew in the blood and/or abscess cultures, Staphylococcus aureus was the most frequent (7 of 15). The most commonly associated pathologic finding was vertebral osteomyelitis (5 of 15). Computed tomography and/or magnetic resonance imaging confirmed the diagnosis of psoas abscesses in all 15 patients. The gallium-67 scan especially aided in the diagnosis of the patients who had initially been diagnosed as having fever of unknown origin (4 of 5) and in the diagnosis of concomitant lesions (9 of 12). Debridement or surgical drainage of the abscess was done in 12 patients. All the patients received adequate antibiotic treatment. However, the mortality rate was 20%. The average hospitalization stay was 42.7 +/- 20.7 days. CONCLUSIONS: Psoas abscess in patients with DM is a disease with both diagnostic and therapeutic challenges. We found the infecting microorganisms to be variable and the mortality rate high.

Adult↗
PubMed1994

The effects of gallium nitrate on osteopenia induced by ovariectomy and a low-calcium diet in rats.

The effects of gallium nitrate (GN) were evaluated on osteopenia induced by ovariectomy (OVX) and a low-calcium diet (LCD) in Sprague-Dawley rats. Twenty-five rats (300-400 g) were randomized into four groups of 5-7 animals: (I) OVX LCD treated with GN for 22 weeks; (II) OVX LCD treated with GN for 10 weeks; (III) OVX LCD treated with saline; and (IV) sham-operated (SO), normal diet, treated with saline. GN-treated rats received a 30-mg/kg subcutaneous single dose of elemental gallium, followed by 10 mg/kg per week, whereas control animals received an equal volume of saline. All animals were euthanized at 22 weeks. Measurements of bone density and histomorphometry, performed on the proximal portion of the tibia, indicated significant bone loss in all OVX LCD animals. GN-treated rats in group I gained significantly less weight than those in the other groups, and their blood urea nitrogen increased, suggesting a nephrotoxic effect. After discontinuation of GN, rats in group II gained weight at the same rate as those which had received only saline. Bone formation rates in the GN-treated rats were double those of the saline-treated OVX animals and more than 10 times those of SO controls. Although the bone formation rate in GN-treated rats increased, GN had no effect in preventing the loss of bone surface, density and volume induced by OVX LCD. These findings suggest that although GN may enhance osteoblastic activity, this agent alone does not appear effective in the prevention of bone loss induced by OVX LCD.

Analysis of Variance↗
PubMed2002

Meso 2,3-dimercaptosuccinic acid (DMSA) and monoisoamyl DMSA effect on gallium arsenide induced pathological liver injury in rats.

The effect of meso 2,3-dimercaptosuccinic acid (DMSA) and monoisoamyl DMSA (MiADMSA) on gallium arsenide (GaAs) induced liver damage was studied. The oral feeding rat model was used in this study. The animals were exposed to 10 mg/kg GaAs, orally, once daily, 5 days a week for 24 weeks and treated thereafter with single oral daily dose of either 0.3 mmol/kg DMSA or MiADMSA for two course of 5 days treatment. The animals were sacrificed thereafter. Lipid peroxidation was assessed by measuring liver thiobarbituric acid reactive substance (TBARS). Liver damage was assessed by number of biochemical variables and by light microscopy. The activity of superoxide dismutase (SOD) and delta-aminolevulinic acid dehydratase (ALAD) beside reduced glutathione (GSH) concentration was measured in blood. Exposure to GaAs produced a significant reduction in GSH while, increased the oxidized glutathione (GSSG) concentration. Hepatic glutathione peroxidase (GPx) and catalase activity increased significantly while level of serum transaminase increased moderately. Gallium arsenide exposure also produced marked hepatic histopathological lesions. Overall, treatment with MiADMSA proved to be better than DMSA in the mobilization of arsenic and in the turnover of some of the above mentioned GaAs sensitive biochemical alterations. Histopathological lesions also, responded more favorably to chelation treatment with MiADMSA than DMSA.

Alanine Transaminase↗
PubMed1998

Acute oral gallium arsenide exposure and changes in certain hematological, hepatic, renal and immunological indices at different time intervals in male Wistar rats.

Male albino rats were given a single oral dose of gallium arsenide (GaAs) (100, 200 or 500 mg/kg). Erythrocyte delta-aminolevulinic acid dehydratase (ALAD) activity was inhibited in all the three GaAs-exposed groups accompanied by elevated urinary excretion of ALA. A significant increase in serum aspartate aminotransferase (AST) activity, and gamma-glutamyltranspeptidase (gamma-GT) was observed. A significant increase in hepatic malondialdehyde (MDA) and a decrease in hepatic glutathione contents were also noted. Renal alkaline phosphatase activity, urinary ALA and protein excretion increased significantly on GaAs exposure. These changes were accompanied by significant alterations in almost all the immunological variables, with an increase in gallium and arsenic concentration in blood and soft tissues. While most of the above biochemical alterations were prominent at day 7 following single exposure to 200 and 500 mg/kg GaAs, most of the immunological indices altered with all the three doses and remained high even at day 21. The results suggest only a moderate effect of GaAs on renal and hepatic tissues. By contrast, immunological and haematological systems are the most vulnerable to the toxic effects of GaAs.

Administration, Oral↗
PubMed2001

Iron and gallium increase iron uptake from transferrin by human melanoma cells: further examination of the ferric ammonium citrate-activated iron uptake process.

Previously we showed that preincubation of cells with ferric ammonium citrate (FAC) resulted in a marked increase in Fe uptake from both (59)Fe-transferrin (Tf) and (59)Fe-citrate (D.R. Richardson, E. Baker, J. Biol. Chem. 267 (1992) 13972-13979; D.R. Richardson, P. Ponka, Biochim. Biophys. Acta 1269 (1995) 105-114). This Fe uptake process was independent of the transferrin receptor and appeared to be activated by free radicals generated via the iron-catalysed Haber-Weiss reaction. To further understand this process, the present investigation was performed. In these experiments, cells were preincubated for 3 h at 37 degrees C with FAC or metal ion solutions and then labelled for 3 h at 37 degrees C with (59)Fe-Tf. Exposure of cells to FAC resulted in Fe uptake from (59)Fe-citrate that became saturated at an Fe concentration of 2.5 microM, while FAC-activated Fe uptake from Tf was not saturable up to 25 microM. In addition, the extent of FAC-activated Fe uptake from citrate was far greater than that from Tf. These results suggest a mechanism where FAC-activated Fe uptake from citrate may result from direct interaction with the transporter, while Fe uptake from Tf appears indirect and less efficient. Preincubation of cells with FAC at 4 degrees C instead of 37 degrees C prevented its effect at stimulating (59)Fe uptake from (59)Fe-Tf, suggesting that an active process was involved. Previous studies by others have shown that FAC can increase ferrireductase activity that may enhance (59)Fe uptake from (59)Fe-Tf. However, there was no difference in the ability of FAC-treated cells compared to controls to reduce ferricyanide to ferrocyanide, suggesting no change in oxidoreductase activity. To examine if activation of this Fe uptake mechanism could occur by incubation with a range of metal ions, cells were preincubated with either FAC, ferric chloride, ferrous sulphate, ferrous ammonium sulphate, gallium nitrate, copper chloride, zinc chloride, or cobalt chloride. Stimulation of (59)Fe uptake from Tf was shown (in order of potency) with ferric chloride, ferrous sulphate, ferrous ammonium sulphate, and gallium nitrate. The other metal ions examined decreased (59)Fe uptake from Tf. The fact that redox-active Cu(II) ion did not stimulate Fe uptake while redox-inactive Ga(III) did, suggests a mechanism of transporter activation not solely dependent on free radical generation. Indeed, the activation of Fe uptake appears dependent on the presence of the Fe atom itself or a metal ion with atomic similarities to Fe (e.g. Ga).

Biological Transport↗
PubMed1999

From crystalline to glassy gallium fluoride materials: an NMR study of 69Ga and 71Ga quadrupolar nuclei.

Owing to the implementation of acquisition techniques specific for nuclei with very large quadrupolar interaction (full shifted echo and variable offset cumulative spectra (VOCS)), NMR spectra of 69Ga and 71Ga are obtained in crystallised (PbGaF5, Pb3Ga2F12, Pb9Ga2F24 and CsZnGaF6) and glassy (PbF2-ZnF2-GaF3) gallium fluorides. Simulations of both static (full echo or VOCS) and 15 kHz MAS spectra allow to obtain consistent determinations of isotropic chemical shifts and very large quadrupolar parameters (nu(Q) up to 14 MHz). In the crystalline compounds whose structures are unknown, the number and the local symmetry of the different gallium sites are tentatively worked out. For the glassy systems, a continuous Czjzek's distribution of the NMR quadrupolar parameters accounts for the particular shape of the NMR spectrum.

Chemical Phenomena↗
PubMed2002

Production and purification of gallium-66 for preparation of tumor-targeting radiopharmaceuticals.

Gallium-66 (T(1/2) = 9.49 h) is an intermediate-lived radionuclide that has potential for positron emission tomography (PET) imaging of biological processes with intermediate to slow target tissue uptake. We have produced (66)Ga by the (66)Zn(p,n) (66)Ga nuclear reaction using a small biomedical cyclotron and have investigated methods for purifying (66)Ga that could be applied to the development of an automated processing system. Measured yields of (66)Ga were very high with a production yield of nearly 14 mCi/microA-h at 14.5 MeV bombardment energy, a value in excellent agreement with theoretical predictions based on literature cross sections for the (66)Zn(p,n) (66)Ga reaction. Gallium-66 has been purified from irradiated zinc targets two ways, by cation-exchange chromatography and diisopropyl ether extraction. The concentrations of stable contaminants in (66)Ga following the two processing methods were determined, and it was found that iron and zinc were present at levels up to an order of magnitude higher after cation-exchange chromatography. The bioconjugates DOTA-Tyr(3)-octreotide and DOTA-biotin were labeled with (66)Ga purified by both methods. Following purification of (66)Ga by solvent extraction, radiochemical yields in excess of 85% were obtained for both compounds, in contrast to much lower labeling yields (less than 20%) obtained after the cation-exchange separation. Higher concentrations of stable contaminants likely contributed to the poor radiochemical yields for labeling DOTA-Tyr(3)-octreotide and DOTA-biotin with cation-exchanged (66)Ga. The lower purity and radiolabeling yields obtained using cation-exchange do not warrant the development of an automated processing system based on this method. Therefore, work is in progress to automate the diisopropyl ether extraction method for routine processing of (66)Ga.

Biotin↗
PubMed2003

Value of gallium-67 scanning in differentiation of malignant tumors from benign tumors or inflammatory disease in the oral and maxillofacial region.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of gallium-67 ((67)Ga) scanning in the differentiation of malignant tumors from benign tumors or inflammatory disease in the oral and maxillofacial region. Study design Fifty-two patients with tumors or inflammation in the oral and maxillofacial region underwent (67)Ga scanning. The results were compared with the final pathologic diagnosis. RESULTS: The gallium-67 scanning images for 20 of 21 patients who had malignant tumors were positive (95.23%); images for 3 out of 20 patients who had benign tumors also were positive (15%). There was a significant difference between malignant and benign tumors (P <.001). Images for 2 of 11 patients with chronic inflammatory lesions were positive (18.2%), but, unlike the images of malignant tumors, the image outlines of the inflammatory lesions were indistinct and larger than the actual lesions. CONCLUSION: (67)Ga scanning is a useful adjunct tool for differentiation of malignant tumors from benign tumors or inflammatory disease in the oral and maxillofacial region.

Adenolymphoma↗
PubMed2005

Diffuse abdominal uptake mimicking peritonitis in gallium inflammatory scan: an unusual feature of acute Q fever.

The clinical features in patients with acute Q fever are variable. We present a patient with fever, abdominal distension, pericardial effusion, and diffuse gallium uptake in the abdominal cavity, mimicking peritonitis or peritoneum carcinomatosis. Serologic surveys revealed acute infection by Coxiella burnetii. The patient responded poorly to doxycycline and improved with oral levofloxacin. During the afebrile period, gallium inflammatory scan showed resolution of previous diffuse uptake in the abdomen, and cardiac echo resolution of pericardial effusion, which was suggestive of peritoneal inflammation related to acute C. burnetii infection. Therefore, clinicians in Taiwan should be alert to the possibility of acute Q fever in patients with fever of unknown cause, especially with clinical evidence of peritoneal and/or pericardial inflammation.

Abdominal Cavity↗