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Strontium(II) sensor based on a modified calix[6]arene in PVC matrix.

5,11,17,23,29,35-Hexakis(1,1,3,3-tetramethylbutyl)-37,38,39,40,41,42-hexakis(carboxy methoxy)calix[6]arene (I) has been evaluated as an ionophore for the analysis of Sr2+. The influences of the nature of the plasticizers (DBA, CN, DOP, NPOE) and of the anion excluder (NaTPB) on the characteristics of the electrode were discussed. The best electrode was fabricated with a membrane having composition 6:150:170:3 (I:PVC:DBA:NaTPB). The response to Sr2+ was Nernstian in the range 1.9 x 10(-5) to 1.0 x 10(-1) M of Sr2+. The influence of pH has also been studied. The electrode exhibited better potential stability and had an operational lifetime of 4 months. The K(A,B)(Pot) values showed that other alkaline earth metal ions are well discriminated. The sensor has also been used as an indicator electrode in the potentiometric titration of sodium carbonate with strontium(II) ions.

Calixarenes↗

Tree-ring strontium-90 and cesium-137 as potential indicators of radioactive pollution.

To examine whether tree rings can be used to detect or assess local historical 90Sr or 137Cs fallout, such as that resulting from the Hiroshima atomic bomb, radial distribution of 90Sr and 137Cs in trees was examined. We studied a gymnosperm [Japanese cedar, Cryptomeria japonica (L. f.) D. Don] and an angiosperm (Japanese persimmon, Diospyros kaki Thunb.) tree species from the vicinity of the atomic bomb hypocenter, and from other locations in Japan. A significant amount of 137Cs was detected in tree rings formed before 1945, indicating lateral migration of Cs. In contrast, the specific activity of 90Sr in the Hiroshima Japanese cedar showed the highest level in 1945, due to relatively immobile characteristics of Sr compared with Cs. Strontium-90 and Sr analyses in tree rings helped identify and distinguish between residual 90Sr activity from the Hiroshima atomic bomb and the atmospheric nuclear testing. This indicates the possibility of detecting or assessing previous local 90Sr pollution through with treering analysis.

Cesium Radioisotopes↗

Strontium-90 in deciduous teeth as a factor in early childhood cancer.

Strontium-90 concentrations in deciduous (baby) teeth of 515 children born mainly after the end of worldwide atmospheric nuclear bomb tests in 1980 are found to equal the concentrations in children born during atmospheric tests in the late 1950s. Recent Sr-90 concentrations in the New York-New Jersey-Long Island metropolitan area have exceeded the expected downward trend seen in both baby teeth and adult bone after the 1963 ban on atmospheric testing. Sharp rises and declines are also seen in Miami, Florida. In Suffolk County, Long Island, Sr-90 concentrations in baby teeth were significantly correlated with cancer incidence for children 0 to 4 years of age. A similar correlation of childhood malignancies with the rise and decline of Sr-90 in deciduous teeth occurred during the peak years of fallout in the 1950s and 1960s. Independent support for the relation between nuclear releases and childhood cancer is provided by a significant correlation with total alpha and beta activities in local surface water in Suffolk County. These results strongly support a major role of nuclear reactor releases in the increase of cancer and other immune-system-related disorders in young American children since the early 1980s.

Child, Preschool↗

Strontium-85 uptake in knee joints with osteochondritis dissecans.

The uptake of Strontium-85 in the distal end of the femur and in the immediate vicinity of the lesion was measured in 12 young ment with ostoechondritis dissecans. The uptake was significantly but only slightly increased. It was confined to the area of the lesion, was less than observed in early cases of gonarthrosis and an order of magnitude less than in cases of osteonecrosis. It is concluded that the repair process of osteochondritis dissecans is very slow and involves only minor part of the bone tissue surrounding the lesion.

Adolescent↗

Radiopharmaceuticals (Strontium 89) and radiosensitizers (idoxuridine).

Strontium 89, a radiopharmaceutical, has proved effective in treating pain associated with multiple osteoblastic bony metastasis from prostate or breast cancer. The drug is given intravenously in an outpatient setting. Pain relief may be noted within 1 to 2 weeks and may last for several weeks or months. Radiosensitizers such as idoxuridine incorporate into the DNA and increase the susceptibility of the cancer cell to radiation damage. Hypoxic cell sensitizers (such as metronidazole, misonidazole, SR 2508, and Ro-038799) increase oxygen to the cancer hypoxic cells and promote damage of the DNA, thus preventing cell repair.

Bone Neoplasms↗

[Treatment of malignant tumors of the conjunctiva with strontium-90 (author's transl)].

Although there are relatively few cases in our series of tumor of the conjunctiva, they represent most frequent histopathologic varieties for this localization. It is difficult to treat these patients in such a way as to cure the tumor while preserving intact the eye and vision. Surgery is recommended only in well differentiated cases that are diagnosed early. The excellent physical properties of strontium-90 make it particularly useful for this type of localization. High doses of radiation can be applied to the tumors with little danger to the deep and sensitive structures of the eye. With fractional doses we have been able to control conjunctival tumors of considerable size and thickness which would not normally have been considered tributary to this type of therapy.

Conjunctiva↗

Local or nonlocal? A research of strontium isotope ratios of teeth and bones on skeletal remains with artificial deformed skulls.

The analysis of strontium isotopic composition of teeth and bone served as an approach to determine nonlocal individuals with artificially deformed skulls in Teuton and Gepid sites. A differing Sr-isotopic composition between tooth and bone from the same skeleton reveals a residence change between early childhood and the last ten years before death. The results show that most Teuton and Gepid individuals investigated are local habitants.

Bone and Bones↗

[Influence of the radioactive strontium (89Sr) using for nuclear medical radiation therapy upon radioactive draining-water system].

PURPOSE: Strontium-89 chloride (89Sr) is a new radiopharmaceutical that provides effective pain relief for metastatic bone lesions, and is expected to be available soon in the palliative management for metastatic bone pain in Japan. Because of relatively long physical half life (50.5 days), 89Sr may affect to the radioactive draining-water system by exceeding the limits of activity concentration for radioactive drain. In this article, the influence of 89Sr use on the radioactive drainage system was simulated. METHODS: The standard tank capacity of drainage and draining frequency was determined from the results of questionnaire carried out for the nationwide medical and research institutes where radioisotope treatment are performed. On the assumption that 89Sr of 148 MBq for one therapy was used twice a week and several common radionuclides were used as the same activity as used at Chiba Cancer Center, the influence of 89Sr was estimated. The calculation was performed using the activity contamination ration into the draining-water system of each radionuclide of 0.01, which was legally determined. RESULTS: The simulation revealed that the sum of the contamination ratios of individual radionuclides exceeded a legal value of 1.0 in standard drainage with the capacity of 5 m3 and 10 m3 and draining frequency of 7 times per year. The actual contamination ratios of common radiopharmaceuticals measured at Chiba Cancer Center ranged from 1/100 to 1/1000 of the legal values. CONCLUSION: It is necessary that the legal value of activity contamination ratios into the draining-water system should be reassessed before starting 89Sr therapy.

Bone Neoplasms↗

Kinetics of the metal cations magnesium, calcium, copper, zinc, strontium, barium, and lead in chronic hemodialysis patients.

BACKGROUND: Dialysis patients are at risk of developing trace element imbalances. To further elucidate the origin of these potential trace element imbalances, plasma and dialysis fluids concentrations of the elements barium (Ba), calcium (Ca), copper (Cu), lead (Pb), magnesium (Mg), strontium (Sr) and zinc (Zn) of seven maintenance dialysis patients were investigated. PATIENTS AND METHODS: In each hemodialysis session 10 to 15 samples of each, whole blood and dialysis liquid before and after passing the artificial kidney were collected. Concentrations of elements were determined by inductively coupled plasma mass spectrometry following strict quality control schemes to guarantee the accuracy and precision of the results. RESULTS: Plasma concentrations of Cu and Zn continuously increased during hemodialysis. Plasma Cu remained within the reference range for healthy adults, whereas plasma Zn was always at or below the reference range in our patients. The behavior of Ca and Sr exhibited extraordinarily strong similarities both in plasma and dialysis liquids, although concentrations of Sr are approximately 2000 times lower. Plasma Ca and Sr were at or above the upper level of the reference range. Plasma Mg concentrations decreased during clinical treatment, but were at the end of dialysis still more than 50% higher than the high end of the reference range. Although concentrations of Ba in dialysis fluids were approximately 10 times lower than in plasma, plasma Ba concentrations (approximately 23 microg/l) were significantly elevated compared to plasma Ba of healthy adults. Initial concentrations of Pb in plasma (0.74 microg/l) were increased by approximately 15% during the clinical treatment and were always higher than the high limit of the reference range. Dialysis liquids had approximately the same Pb concentrations (0.5 to 1.3 microg/l) as found in the plasma of our patients but with higher concentrations at the inlet of the dialyzer. CONCLUSION: This study could give an insight into the kinetics of trace element concentrations during dialysis, the clinical relevance of which needs to be further elucidated.

Adult↗

[Comparison of rhenium-188, rhenium-186-HEDP and strontium-89 in palliation of painful bone metastases].

AIM: Several radiopharmaceuticals were compared previously with regard to the efficiency in pain palliation of bone metastases. Furthermore, first results were reported on the suitability for such kind of therapy of the generator produced radionuclide rhenium-188. METHOD: Influence of Rhenium-188-HEDP (Re-188), Rhenium-186-HEDP (Re-186) and Strontium-89 (Sr-89) on pain symptoms and bone marrow function were obtained in 44 patients (pts). These were 16 pts. with Re-188 (2943 +/- 609 MBq), 13 pts. with Re-186 (1341 +/- 161 MBq) and 15 pts. with Sr-89 (152 +/- 18 MBq) (6 woman with breast cancer and 38 men with prostata cancer). RESULTS: 81 of pts. after Re-188, 77% after Re-186 and 80% after Sr-89 reported relief of pain. The Karnofsky-Index established by pts. increased from 74 +/- 9% to 85 +/- 11% after Re-188, from 70 +/- 11% to 76 +/- 11% after Re-186 and from 62 +/- 10% to 69 +/- 10% after Sr-89. However, the difference between the pre- and the post-therapeutic value is only statistically significant in the case of Re-188 therapy (p = 0.001). A decrease of platelets of 30 +/- 14% after 2.8 +/- 0.7 for pts. treated with Re-188, of 39 +/- 20% after 3.7 +/- 1.0 weeks for pts. treated with Re-186 and of 34 +/- 26% after 4.4 +/- 1.0 weeks for pts. treated with Sr-89 compared to the value before therapy was observed. The difference was not significant between the 3 groups of pts. (p = 0.125 to 0.862). CONCLUSION: All tried radiopharmaceuticals were effective in pain palliation. The various radionuclides had no significant difference in the pain relief or the bone marrow impairment. If only the Karnofsky-Index after Re-188 HEDP seems to be a little more increase.

Bone Neoplasms↗

Bone pain palliation with strontium-89 in cancer patients with bone metastases.

Strontium-89 is a pure beta-emitting radioisotope, a chemical analogue of calcium, and it is therefore avidly concentrated by areas of high osteoblastic activity. Selective uptake and prolonged retention at sites of increased bone mineral turnover provide precise bone lesions targeting. 89Sr chloride (commercialised as Metastron) is typically administered in a single 150 MBq parenteral dose. Its radioactive emission poses very little radioprotection concerns. Overall, studies show pain relief in up to 80% of patients, of which 10 to 40% became effectively pain free. The mean duration of palliation was 3-4 months. The mechanism of pain relief is controversial ; it is probably, but not only, related to the absorbed dose in the tumour and bone. There is no clear dose-response relationship. The only reported toxicity is temporary myelosuppression. WBC and platelets should be monitored at least on a weekly basis until they return to baseline. It seems that only patients with a reasonably good general condition stand to benefit from this treatment. In conclusion, systemic radionuclide therapy using 89Sr represents a feasible, safe, effective, well tolerated and cost-effective palliative treatment in patients with refractory bone pain.

Bone Neoplasms↗

Sulfate-selective PVC membrane electrode based on a strontium Schiff's base complex.

A strontium Schiff's base complex (SS) can be used as a suitable ionophore to prepare a sulfate-selective PVC-based membrane electrode. The use of oleic acid (OA) and hexadecyltrimethylammonium bromide (HTAB), as additives, and nitrobenzen (NB), dibutyl phthalate (DBP) and benzyl acetate (BA) as solvent mediators, were investigated. The best performance was observed with a membrane composition PVC: NB: SS: HTAB of 30%: 62%: 5%: 3% ratio. The resulting sensor works well over a wide concentration range (1.0 x 10(-2)-1.0 x 10(-6) M) with a Nernstian slope of -29.2 mV per decade of sulfate activity over a pH range 4.0-7.0. The limit of detection of the electrode is 5 x 10(-7) M. The proposed sensor shows excellent discriminating ability toward SO4(2-) ions with regard to many anions. It has a fast response time of about 15 s. The membrane electrode was used to the determination of zinc in zinc sulfate tablets. The sensor was also used as an indicator electrode in the potentiometric titration of SO4(2-) against barium ion.

Ion-Selective Electrodes↗

Histologic studies of splenic megakaryocytes after bone marrow ablation with strontium 90.

We previously showed that purified strontium 90 produced sustained bone marrow ablation in mice, lowering platelet levels to less than 10% of normal 11 days after administration. Platelet levels later rose exclusively from splenic production and were maintained at a stable level (58% of normal) from 20 to 115 days after injection. However, there was no change in the total number or ploidy distribution of splenic megakaryocytes, as immunologically detected by flow cytometry. To further study the characteristics of splenic thrombopoiesis after bone marrow ablation by 90Sr, we measured the frequency, cross-sectional area, and endomitotic figures of histologically recognizable megakaryocytes (as well as bare megakaryocyte nuclei) in mouse spleen sections. During the hematopoietic nadir 9 days after injection of yttrium 90-free 90Sr, the size (area) of megakaryocyte cross-sections (mean +/- SD, 1079.3 +/- 661.6 microns 2; normal, 398.7 +/- 192.8 microns 2) was greater than for any other time studied, but megakaryocyte frequency (corrected for size) did not increase until day 16. Overall, splenic megakaryocytes in marrow-ablated mice 16 or more days after 90Sr injection showed substantial increases (p = 0.001 for both comparisons) in mean area (707.5 +/- 386.2 microns 2) and sectional frequency (mean +/- SEM, 4.52 +/- 0.20 per 1.83 mm2; normal, 0.78 +/- 0.06 per 1.83 mm2). Megakaryocyte bare nuclei and endomitotic figures were also more numerous after 90Sr, injection, suggesting acceleration of megakaryocyte maturation and platelet production. The induction of splenic platelet production after bone marrow ablation is associated with increased size of recognizable megakaryocytes, despite lack of change in overall splenic megakaryocyte ploidy.

Animals↗

[Treatment of symptomatic bone metastases of prostatic carcinoma with strontium (Sr-89) chloride: initial experience].

Until now, patients with a progressive prostatic cancer, in whom all therapies failed and the disease spread locally and distally, was considered "a lost patient"; because it did not exist an effective therapy easily to be used. The skeletal pain control is a serious problem and it is a great responsibility also for the Urologists especially if the patient has not a short survival time and the quality of life very poor. Physicians feel the need for a systemic, well tolerated and effective therapy also for a long time, uniform and repeatable, able to be efficient for these patients. Strontium 89 chloride seems to offer all those possibilities and to be the best procedure for Urologist, Radiotherapists and Nuclear Specialists in order to satisfy the patients requirements. International research has shown Sr-89 Chloride is a powerful new therapy. Sr-90 Chloride is a radiopharmaceutical product for the treatment of painful metastases from prostatic cancer. It is a new treatment but its effectiveness is well documented and results are reported in the most important international literature. In our Department a clinical research has started and our purpose is to produce more data for a clinical and biological evaluation of the results hoping that a similar research will extend as a multicenter study.

Bone Neoplasms↗

[A multicenter study to determine the efficacy and safety of strontium (89Sr) chloride for palliation of painful bony metastases in cancer patients].

PURPOSE: A multicenter study was conducted to evaluate the efficacy of strontium chloride (89SrCl2) for palliation of painful bony metastases using the Visual Analogue Scale (VAS), Brief Pain Inventory (BPI) and Functional Assessment for Cancer Therapy-General (FACT-G). METHODS: Ninety patients received a single injection of 2.0 MBq/kg and were classified as responders if VAS scores decreased without increased use of analgesics or if analgesic consumption decreased without an increase in the VAS. RESULTS: In the 69 subjects that could be evaluated, mean VAS values decreased significantly from 48.0 +/- 20.8 mm at baseline to 24.1 +/- 22.3 mm at last visit(Week 12) (p < 0.0001). VAS decreased more than 10 mm in 58.0% of these subjects, and analgesic consumption was reduced more than 10% in 39.1% of subjects. The response rates were 46.4% (95% confidence interval (CI) 34.3-58.8%) in the 69 subjects that could be evaluated and 43.3% (95% CI 32.9-54.2%) in all subjects. The scoring in BPI for interference in daily life improved together with improvement in its pain scores. Total FACT-G score showed significant improvement, as did its score in the subsection of physical well-being. Both platelets and leucocytes decreased by 22% at nadir (week 8), and such profiles of myelosuppression by 89SrCl2 were similar to those in the previous clinical studies. CONCLUSION: These results suggest the clinical utility of 89SrCl2 for pain palliation, which leads to QOL improvement in patients with painful generalized bone metastases.

Adult↗

Strontium-89 and low-dose infusion cisplatin for patients with hormone refractory prostate carcinoma metastatic to bone: a preliminary report.

Strontium-89 has been used for the treatment of painful bony metastases in patients suffering from disseminated adenocarcinoma of the prostate, with a variable proportion of patients obtaining clinically significant reductions in analgesic requirements. Based on data revealing enhancement of continuous low-dose rate irradiation by low-dose cisplatin in murine models, a protocol using 148 MBq (4 mCi) of 89Sr and 35 mg/m2 of cisplatin infused over 2 days, 1 and 4 wk after administration of the radioisotope was undertaken. Preliminary data suggest good pain relief with 55% of 18 patients entered thus far obtaining at least a 50% reduction in analgesic requirements. Improvements in total alkaline phosphatase and serum lactate dehydrogenase have consistently been seen, with some patients exhibiting improvements in hemoglobin, tumor markers and bone scans. Toxicity appears to be mild, with no life-threatening complications. In particular, myelosuppression after one course of treatment was modest, but retreatments in two patients has resulted in grade 3 hematologic toxicity. Two patients developed a "pain flare" after administration of cisplatin. Further accrual to this study will allow more accurate determination of pain response rate, and improved evaluation of parameters of objective response.

Adenocarcinoma↗

The mechanical properties and solubility of strontium-substituted hydroxyapatite.

The mechanical properties and solubility of sintered Sr-substituted hydroxyapatites were examined in order to investigate the influences of Sr incorporation into hydroxyapatite in bones and teeth on them. Hydroxyapatite (HAp), Sr-substituted hydroxyapatite (Ca.SrAp), and strontium-hydroxyapatite (SrAp) were synthesized and sintered. The bending strength and Young's modulus were measured. Also, solubility in isotonic NaCl solution was examined. The Young's modulus of Sr-substituted hydroxyapatite (Sr wt% = 1.0) and hydroxyapatite surface treated with Sr ion were greater than that of hydroxyapatite. The bending strengths of Sr-substituted hydroxyapatites (Sr/Ca = 4/6 and less) were reduced slightly compared to that of hydroxyapatite. The bending strength of hydroxyapatite surface treated with Sr ion was increased compared to that of hydroxyapatite. The solubility in isotonic NaCl solution at 37 degrees C was increased with an increase in Sr content. The effects of Sr on the mechanical properties and solubility of bones and/or teeth are discussed.

Biomechanical Phenomena↗