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PubMed1997

[Spectrophotometric determination of scandium,gallium and vanadium in white cabbage leaves].

Scandium, gallium and vanadium contents in plants is on the ppm level, although plants from industrial areas can show higher concentrations of these elements. In Department of Analytical Chemistry of Silesian University there have been elaborated new, sensitive, spectrophotometric methods of determination of scandium, gallium and vanadium using Chrome Azurol S (CAS) and Sterinol (ST). The aim of this study was the application of these methods in analysis of cultivated plants from polluted regions. White cabbage from Upper Silesia was chosen. Because the spectrophotometric methods are not selective, scandium, gallium and vanadium should be preliminary separated from interfering elements. The solvent reaction was applied for the isolation from main and trace components of investigated material. Tienoiltrifluoracetone solution in xylene was used for the extraction of scandium, mesithyloxide for vanadium and n-butyl acetate--for gallium. Interfering and not separated Fe(III) was isolated using the extraction with acetylacetone solution in CHCl3 in the case of scandium and the reduction to Fe(II) by ascorbic acid in the case of gallium and vanadium. Due to influence of Fe(II) on the vanadium determination, KCN was used as a masking agent directly after the reduction. Scandium, gallium and vanadium were determined in 6 independent samples of white cabbage after dry or wet mineralization and contents of these leemnets were found from calibration graphs. Obtain results were checked by the internal standard addition method and Atomic Emission Spectrometry Method (ICP AES). The amounts of gallium and vanadium in white cabbage from Upper Silesia District determined by elaborated methods are in good correlation with a literature data, although the contents of vanadium are on the toxic level. The scandium concentration is higher than in plants from not industrial areas. The standard recovery is satisfactory. The Atomic Emission Spectrometry Method gave comparable results. The proposed the spectrophotometric methods are sensitive, precise and economical too, because they require only small amounts of reagents and simple not expensive apparatus. The methods can be recommended for many laboratories to the analytical control of white cabbage and after adaptation to the other plant material analysis.

Brassica↗
PubMed1988

Gallium-transferrin as a macromolecular tracer of vascular permeability.

Labeling of plasma transferrin with gallium was investigated to determine whether the gallium-transferrin complex could be effectively used as a macromolecular tracer in studies of capillary permeability using Positron Emission Tomography (PET). Three gallium-plasma preparations were tested and 2 h biodistribution studies were performed in rats. The three preparations gave similar blood clearance and tissue distribution data, but the methods used for evaluating gallium-transferrin binding were found to be suboptimal. Gallium clearance from blood was biexpoential with both components faster than that of 125I-albumin. Gallium distribution spaces in all tissues including intracerebral Walker-256 tumors were larger than those of albumin. These results indicate a relative instability of the gallium-transferrin complex in vivo, which appears to preclude its use as an acceptable radiolabeled protein for vascular permeability studies using PET.

Animals↗
PubMed2005

Hydrogen chemisorption on gallium oxide polymorphs.

The chemisorption of H(2) over a set of gallia polymorphs (alpha-, beta-, and gamma-Ga(2)O(3)) has been studied by temperature-programmed adsorption equilibrium and desorption (TPA and TPD, respectively) experiments, using in situ transmission infrared spectroscopy. Upon heating the gallium oxides above 500 K in 101.3 kPa of H(2), two overlapped infrared signals developed. The 2003- and 1980-cm(-1) bands were assigned to the stretching frequencies of H bonded to coordinatively unsaturated (cus) gallium cations in tetrahedral and octahedral positions [nu(Ga(t)-H) and nu(Ga(o)-H), respectively]. Irrespective to the gallium cation geometrical environment, (i) a linear relationship between the integrated intensity of the whole nu(Ga-H) infrared band versus the Brunauer-Emmett-Teller surface area of the gallia was found and (ii) TPA and TPD results revealed that molecular hydrogen is dissociatively chemisorbed on any bulk gallium oxide polymorph following two reaction pathways. An endothermal, homolytic dissociation occurs over surface cus-gallium sites at T > 450 K, giving rise to Ga-H(I) bonds. The heat and entropy of this type I hydrogen adsorption were determined by the Langmuir's adsorption model as Deltah(I) = 155 +/- 25 kJ mol(-1) and Deltas(I) = 0.27 +/- 0.11 kJ mol(-1) K(-1). In addition, another exothermic, heterolytic adsorption sets in already in the low-temperature region. This type of hydrogen chemisorption involves surface Ga-O-Ga species, originating GaO-H and Ga-H(II) bonds which can only be removed from the gallia surface after heating under evacuation at T > 650 K. The measured desorption energy of this last, second-order process was equal to 77 +/- 10 kJ mol(-1). The potential of the H(2) chemisorption as a tool to measure or estimate the specific surface area of gallia and to discern the nature and proportion of gallium cation coordination sites on the surface of bulk gallium oxides is also analyzed.

Journal Article↗
PubMed2004

Preconcentration of gallium by coprecipitation with synthetic zeolites prior to determination by electrothermal atomic absorption spectrometry.

Synthetic zeolites were dissolved in nitric acid, and the resulting solution used as a coprecipitant for the preconcentration of trace amounts of gallium in water samples prior to determination by electrothermal atomic absorption spectrometry (ETAAS). The gallium preconcentration conditions and the ETAAS measurement conditions were optimized. Gallium was quantitatively concentrated with the zeolites coprecipitate from pH 6.0 to 8.0. The coprecipitate was easily dissolved in nitric acid, and an aliquot of the resulting solution was introduced directly into a tungsten metal furnace. The atomic absorbance of gallium in the resulting solution was measured by ETAAS. An ashing temperature of 400 degrees C and an atomizing temperature of 2600 degrees C were selected. The calibration curve was linear up to 3.0 microg of gallium and passed through the origin. The detection limit (S/N > or = 3) for gallium was 0.08 microg/100 cm3. The relative standard deviation at 1.0 microg/100 cm3 was 3.0% (n = 5). The proposed method has been successfully applied to trace gallium analysis in environmental water samples.

Journal Article↗
PubMed1988

Gallium-67 scanning in the staging of cryptogenetic fibrosing alveolitis and hypersensitivity pneumonitis.

Gallium-67 citrate is known to localize within inflammatory sites. Gallium-67 scanning is used for the evaluation of lung inflammation (i.e. alveolitis) during interstitial lung diseases. We investigated 27 patients with cryptogenetic fibrosing alveolitis (n = 17) and hypersensitivity pneumonitis (n = 10) using gallium-67 lung scanning and lung function tests (forced vital capacity, diffusing capacity, resting and exercise blood gases). Investigations were performed before and after one year of methylprednisolone treatment. None of eight healthy volunteers had any abnormal gallium-67 uptake. In all patients with cryptogenetic fibrosing alveolitis an initial abnormal gallium-67 uptake was observed (mean fixation index: 163 +/- 18). In addition, analysis of lung function tests a year after initial evaluation showed that unchanged or improving patients presented initially with a lower gallium-67 index than patients with evidence of deterioration (153.9 +/- 23.7 vs 251.0 +/- 23.3.; p less than 0.01). Similarly, among patients with hypersensitivity pneumonitis the index was lower in unchanged or improving patients than in those with deterioration (74.9 +/- 22 vs 226.7 +/- 4.9; p less than 0.05). Thus gallium-67 scanning is useful in the management of cryptogenetic fibrosing alveolitis and hypersensitivity pneumonitis.

Alveolitis, Extrinsic Allergic↗
PubMed1978

Studies on gallium accumulation in inflammatory lesions: III. roles of polymorphonuclear leukocytes and bacterial.

The role of polymorphonuclear leukocytes (PMN) and bacteria in the accumulation of gallium-67 in inflammatory lesions was studied using an animal model. A plastic practice golf ball was implanted in the subcutaneous tissue of the abdominal wall of rabbits, and sterile or bacterial inflammation was induced inside the ball. Gallium accumulated in the inflammatory exudates induced by either sterile casein or Staphylococcus aureus. Two rabbits were made agranulocytic by prior treatment with myleran before the injection of S. aureus and gallium. These also accumulated gallium, although in one agranulocytic rabbit there were no PMN in the inflammatory exudate. Analysis of the inflammatory exudates showed that most of the gallium was in the noncellular fraction (2,500-g supernatant) in both sterile and bacteria-induced inflammation. The results indicate that gallium accumulates in the inflammatory lesions, even in the absence of either PMN or bacteria.

Animals↗
PubMed1980

Pharmacokinetics of gallium nitrate in man.

Gallium nitrate is a new antineoplastic agent that has shown activity in a number of in vitro tumor systems. During a Phase I clinical trial, the pharmacokinetics of two methods of administration of gallium nitrate were studied: a seven-day continuous intravenous infusion, and a weekly rapid intravenous infusion. During the continuous infusion of 200 mg/M2 of gallium nitrate, plasma gallium concentrations of 0.9 +/- 0.2 microgram/ml in one patient, and 1.9 +/- 0.4 microgram/ml in a second were noted. Urine excretion of gallium approximated the daily administered dose by day 2-3. Overall, 68-107% of the total administered dose was recovered in the urine. Following a rapid intravenous infusion, a biphasic curve was generated. The T1/2 alpha ranged from 8.3-26 minutes; the T1/2 beta from 6.3-196 hours. From 69-91% of the administered dose was recovered in the urine. The effects of gallium nitrate on tissue localization and body retention of 67Ga are also presented.

Adolescent↗
PubMed1989

Efficacy of computed tomography of the thorax and upper abdomen and whole-body gallium scintigraphy for staging of lung cancer.

To assess the efficacy of performing both computed tomography (CT) of the thorax and upper abdomen and whole-body gallium scintigraphy for staging lung cancer, the results of each test were compared with those obtained by chest radiography and clinical examination in 100 patients. Clinical efficacy was defined in terms of accuracy in staging the tumor based either on surgery, biopsy, or clinical and radiologic follow-up. The CT provided significantly superior accuracy in 27 patients and minor additional staging information in 17 patients compared with the gallium scan. Whole-body gallium scintigraphy provided important additional information in nine patients and minor additional information in a further eight. The diagnostic yield of CT and gallium scanning was considered equivalent in 39 cases. Of the nine cases in which gallium was significantly superior to CT, clinical findings which suggested the presence of metastases had been noted before the scan in four cases. The authors' results confirm the utility of CT for staging lung cancer and indicate that the additional yield from gallium scintigraphy is relatively low provided a thorough history and physical examination have been performed.

Adult↗
PubMed1990

Role of the gallium scan in Hodgkin's disease.

The reports of 240 gallium scans on 165 patients with Hodgkin's disease were reviewed to compare results with higher doses with those in earlier studies that employed lower doses. Tracer concentrations in specific sites were correlated with radiologic and pathologic reports and with the clinical courses of the patients studied. There were no significant differences in overall results between newer and older gallium scanning techniques. For untreated patients, the overall sensitivity was only 64%, but the overall specificity was 98%. For untreated patients and for patients with relapsing disease, the presence of gallium concentration in a specific site was highly predictive of active Hodgkin's disease at that site. However, for routine follow-up of treated patients, 95% of unsuspected relapses were missed by the scan, indicating the limited usefulness of negative scan results in this setting. For patients with residual abnormalities after therapy, demonstrated by other radiographic means, increased uptake of gallium in abdominal or peripheral lymph nodes also indicated active disease, although lack of uptake was reliable only in the mediastinum. Based on these results, it appears that the higher doses used in this study have not substantially improved the role of gallium scanning in this disease. Although it is potentially useful in providing confirmatory data at diagnosis or in patients with new or residual objective abnormalities after treatment, routine use of gallium scanning in Hodgkin's disease is not recommended.

Gallium Radioisotopes↗
PubMed1993

Quantitative bone gallium scintigraphy in osteomyelitis.

Gallium imaging offers many practical advantages over indium-111-labeled leukocyte imaging, and calculating quantitative ratios in addition to performing the routine bone-gallium images allows accurate and easy evaluation of patients with suspected osteomyelitis. To add objectivity and improve the accuracy and confidence in diagnosis of osteomyelitis, quantitative comparison of abnormalities seen on bone scans and gallium scans was performed. One hundred and ten adult patients with 126 sites of suspected osteomyelitis were evaluated and categorized by gallium-to-bone ratios, gallium-to-background ratios, and spatial incongruency of gallium and bone activity. Combined evaluation using these criteria gave a 70% sensitivity and 93% specificity for the diagnosis of osteomyelitis.

Adult↗
PubMed1986

Effects of iron-limitation of Escherichia coli on growth, the respiratory chains and gallium uptake.

The effects of iron limitation on growth, the composition and function of the respiratory chains, and gallium uptake in Escherichia coli have been studied. Decreasing the iron concentration in a defined medium using Chelex resin gave lower growth yields in both continuous culture and prolonged batch culture. In the former, iron-limited (entering [Fe] less than or equal to 2.0 microM) cells exhibited diminished respiration rates, respiration-driven proton translocation quotients, and levels of non-haem iron and cytochromes. The cellular concentration of haemoprotein b-590 (a cytochrome alpha 1-like hydroperoxidase) decreased 20-fold on iron limitation, whilst a CO-binding pigment with an absorption maximum in the dithionite-treated form near 500 nm appeared. Gallium(III) (9 microM) added to iron-limited, but not iron-sufficient, cultures diminished growth yields further; cells grown with low entering concentrations of iron took up less gallium than iron-sufficient cells. These results are attributed to the interference by gallium(III) with siderophore-mediated metal uptake. Gallium also stimulated iron uptake and was itself accumulated by iron-sufficient cells, suggesting that gallium(III) also affects the iron transport system(s) of low affinity.

Escherichia coli↗
PubMed1987

Predictive value of gallium scan, angiotensin-converting enzyme level, and bronchoalveolar lavage in two-year follow-up of pulmonary sarcoidosis.

Evaluation of patients with pulmonary sarcoidosis with serum angiotensin-converting enzyme (ACE), gallium scan, and bronchoalveolar lavage (BAL) has proved useful in demonstrating active disease, especially in the lungs. Long-term prognosis based on the results of pretreatment ACE, gallium scan, and BAL has not been previously clarified. We studied 44 patients with initially symptomatic pulmonary sarcoidosis who were begun on steroid therapy after initial evaluation. At 2 years, 21 of 44 (48%) patients still had worsening disease. Of 31 patients who had positive gallium scan pretreatment, 21 (68%) still had worsening disease at 2 years. None of the 13 patients with a negative gallium scan had worsening disease at 2 years (Chi square = 14.2, P less than 0.01). Similar analysis of the pretreatment serum ACE level, percentage of lymphocytes in the BAL fluid, and ratio of T-helper/inducer to T-suppressor/cytotoxic (T4/T8) in the BAL fluid also had some predictive value for worsening disease at 2 years; however, these tests were less sensitive than the gallium scan. In patients with pulmonary sarcoidosis, the finding of a negative gallium scan suggests a small likelihood that disease activity will worsen after 2 years.

Adult↗
PubMed2000

Flame atomic absorption spectrometric determination of lead in waste water and effluent after preconcentration using a rapid coprecipitation technique with gallium phosphate.

A determination method for lead in waste water and effluent was studied using flame atomic absorption spectrometry after preconcentration of lead by the rapid coprecipitation technique with gallium phosphate. Lead ranging from 0.5 to 50 microg was quantitatively coprecipitated with gallium phosphate from 100-150 mL sample solution (pH approximately 5). The presence of gallium phosphate did not affect the atomic absorbance of lead. Since the concentration of gallium in the final sample solution is also measurable by flame atomic absorption spectrometry at 250.0 nm without further dilution, the rapid coprecipitation technique, which does not require complete collection of the precipitate, becomes possible using a known amount of gallium and measuring the concentrations of both lead and gallium in the final sample solution by flame atomic absorption spectrometry. The 32 diverse ions tested gave no significant interferences in the lead determination. The method proposed here is rapid and has good reproducibility.

Calibration↗
PubMed2002

Clinical features and gallium scan in the detection of post-surgical infection in the elderly.

Common signs of infection, such as an elevated level of C-reactive protein (CRP), raised white blood cell (WBC) count and increased temperature, may not be present in elderly patients when infection occurs. In addition, these typical signs may be normal events during the postoperative period. Therefore, early detection of post-surgical infection may be difficult in the elderly population. In this study, we evaluated the usefulness of gallium scan in the detection of infection in elderly patients after colorectal surgery and compared it with CRP, WBC count and ear temperature (ET) examinations. Thirty-three patients undergoing colorectal surgery and aged over 60 years were enrolled in the study. All patients underwent a gallium scan and CRP, WBC and ET examinations. Of the 33 patients, 18 (54.5%) were diagnosed with infection. The diagnostic sensitivity was 100% for both gallium scan and the CRP test, but only 44.4% and 61.1% for the WBC count and ET, respectively. The diagnostic specificity of the gallium scan, WBC count and ET was 80% or more, whereas that of the CRP test was only 53.3%. The diagnostic accuracy of gallium scan, CRP test, WBC count and ET was 90.9%, 78.8%, 60.6% and 72.7%, respectively. In conclusion, both WBC and ET examinations show low sensitivity in the detection of infection in the elderly population after colorectal surgery. The CRP test has good sensitivity but low specificity. Of the four diagnostic modalities, gallium scan had the highest overall diagnostic accuracy (90.9%) while the WBC test had the lowest (60.6%).

Abdominal Abscess↗
PubMed1982

Tumor cell toxicity of stable gallium nitrate: enhancement by transferrin and protection by iron.

The cytotoxicity of citrated gallium nitrate (NSC 15200) to EMT-6/UW mouse sarcoma cells growing in vitro was assayed as growth inhibition in treated cultures as well as cell survival (colony-forming ability) after acute or chronic exposure to graded doses. Gallium nitrate is both cytostatic and lethal to cells, with some growth inhibition occurring after chronic exposure to low doses (10 micrograms/ml) which kill essentially no cells. Cell kill and growth inhibition were both observed if cells were exposed for 24 hr or more to doses greater than 50 micrograms/ml. The growth inhibitory and lethal effects of gallium nitrate were enhanced by the addition of human transferrin to the medium. This enhanced toxicity was consistent with, and proportional to, the increased gallium uptake in the presence of transferrin rather than a direct effect of this iron transport protein. The addition of ferric citrate greatly reduced the toxic effect of the gallium salt. Cells in stationary plateau phase cultures appear to be as sensitive to gallium nitrate as exponentially growing cells. Ga3+ may mimic Fe3+ in some aspects of cellular metabolism, and competition between the two metals occurs at the initial uptake step, binding to transferrin, and possibly at other points in cell metabolism.

Animals↗
PubMed1993

Evaluation of the reproductive toxicity of gallium nitrate in mice.

Reproduction studies were performed with gallium nitrate, an antihypercalcaemic drug that is also used as a chemotherapeutic agent for the treatment of certain malignancies. Male mice were injected subcutaneously with gallium nitrate at doses of 0 (controls), 24, 48 and 96 mg/kg/day every other day for 14 days before mating with untreated females. Fertility and reproductive performance in the gallium nitrate-treated groups did not differ significantly from controls. No significant changes were observed in the relative testes and epididymis weights. Sperm counts in the gallium nitrate-dosed groups were comparable with those in the control group, whereas the percentage of motile cells was similar between treated and untreated animals. Histopathological examination of the testes and epididymis did not reveal any changes at any dose of gallium nitrate. The no-observed-adverse effect level was 96 mg/kg body weight. This dose is about 30 times higher than the current doses of gallium nitrate administered to humans.

Animals↗
PubMed1993

Handling characteristics of gallium alloy for dental restoration.

The handling characteristics of a gallium alloy (Gallium Alloy GF) were compared to those of a spherical high-copper amalgam (Tytin). Ten dentists each restored four identical MO preparations in acrylic typodont teeth (no. 30), two with amalgam and two with gallium alloy. Each restoration was evaluated immediately following completion by the operator for six clinically relevant criteria. Each criterion was scored between 1 and 5, where 1 = very poor, 2 = poor, 3 = fair, 4 = good, and 5 = very good. Three two-sided Mann-Whitney tests were used to compare the median scores for significant differences (P < 0.05). The first test indicated no significant difference between scores for the first- and second-placed restorations, within criteria and within alloy type (n = 10). The second test indicated a significant difference between amalgam and gallium alloy, within criteria and within restoration sequence (n = 10), for each criterion except resistance to fracture during removal of the matrix band. The third test indicated a significant difference between amalgam and gallium alloy, within each criteria, combining scores for first- and second-placed restorations (n = 20). During simulated clinical placement, amalgam was rated significantly higher than gallium alloy in each handling characteristic evaluated.

Dental Alloys↗
PubMedDate not supplied

Differential effects of gallium nitrate on proliferation of brain tumor cells in vitro.

Gallium nitrate possesses antineoplastic activity against certain solid tumors; however, no studies exist regarding the effect of this metal on brain tumor cell proliferation. Several human brain tumor and rhabdomyosarcoma cell lines were incubated with increasing concentrations of gallium nitrate and cell proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The growth of medulloblastoma 324, rhabdomyosarcoma TE671, and RD cells was markedly inhibited by gallium nitrate, while glioblastoma cell growth was only moderately inhibited (U373 cells) or actually stimulated (U87 cells). Gallium inhibited the cellular uptake of 59Fe; however, this block in 59Fe uptake was variable and closely paralleled the inhibitory effects of gallium on cell growth. Intracellularly, gallium may interfere with DNA synthesis by inhibiting ribonucleotide reductase. Such effects may be of relevance in the treatment of brain tumors with this metal.

Antineoplastic Agents↗