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PubMed2003

Improvements in the biokinetic model for strontium with allowance for age and gender differences in bone mineral metabolism.

An age- and gender-dependent biokinetic model for strontium was developed based on the study of a population living along the Techa River exposed to effluents from the Mayak Production Association (MPA). To estimate the parameters of a new model (Techa biokinetic model, TBM) many data sets have been assembled: our whole-body counter data on long-term retention of 90Sr in humans, data from studies during the period of global fallout, data resulting from deliberate injection of strontium radionuclides and non-radiological data regarding bone formation and resorption, mineral content of the body, etc. The model was developed using the basic structure of the ICRP biokinetic model for strontium, but new age- and gender-specific parameters were derived. This paper discusses the approaches applied to develop the new model.

Adolescent↗
PubMed1999

Disseminated intravascular coagulation in a patient treated with strontium-89 for metastatic carcinoma of the prostate.

Strontium-89 is effective in the palliation of bone pain caused by skeletal metastases. Its primary side effect is mild thrombocytopenia that typically recovers in 3 or 4 months. Subclinical disseminated intravascular coagulation is reported to be present in approximately 10% to 20% of patients with advanced prostate cancer. These patients may be at increased risk for severe marrow depression after radionuclide therapy for bone pain palliation. This report describes a patient with painful bony metastases resulting from prostate carcinoma. He had a normal platelet count and no clinical evidence of a coagulation disorder at the time of strontium-89 therapy, and a severe disseminated intravascular coagulation developed and lead to death after treatment. A normal platelet count before strontium-89 therapy does not preclude subsequent disseminated intravascular coagulation, and we support the Society of Nuclear Medicine's bone pain treatment procedure guideline that patients referred for bone palliation should be screened for disseminated intravascular coagulation before therapy.

Adenocarcinoma↗
PubMed2001

Estimation of dietary 232Th, 238U, cesium, and strontium intakes in Vietnamese people from different geographical regions.

Diet samples were collected to estimate dietary intakes of 232Th, 238U, cesium, and strontium for Vietnamese adults using duplicate portion studies and market basket studies. Average concentrations of 232Th, 238U, cesium, and strontium in diet samples were 4.0 ng/g-dry, 2.5 ng/g-dry, 41 ng/g-dry, and 4.5 ng/g-dry, respectively. Daily intakes per person for 232Th, 238U, cesium, and strontium were estimated to be 0.99 microg, 0.66 microg, 10 microg, and 1.2 mg, respectively. Daily intakes of 232Th, 238U, and cesium differed statistically between northern and southern of Vietnam, depending on geological conditions and food habits. However, intakes of the four nuclides were similar to the global averages.

Adult↗
PubMed2004

Contents of cesium, iodine, strontium, thorium, and uranium in selected human organs of adult asian population.

Contents of cesium, iodine, strontium, thorium, and uranium in some selected human organs were estimated for adult Asian population using data obtained in four Asian countries: China, India, Philippines, and Republic of Korea, as part of a Coordinated Research Program of the International Atomic Energy Agency on "Ingestion and Organ contents of elements of importance in radiation protection." These countries together represent more than 40% of the world population. Highly sensitive analytical techniques were employed to measure cesium in skeletal muscle, iodine in thyroid, strontium in skeleton, thorium and uranium in skeleton, liver, kidneys, and lungs where, in comparison to other organs, these elements are present in higher concentrations. The organ contents for adult Asian population, when compared with the corresponding data proposed for Reference Man by International Commission on Radiological Protection (ICRP), showed about 40 times lower kidneys content and about 10 times lower skeleton content of uranium. The content of thorium in skeleton for Asian population was also half of the ICRP Reference Man value. Interestingly, organ contents for the other elements such as iodine in thyroid, cesium in skeletal muscle, and strontium in skeleton were comparable for Asian and the Caucasian population (represented by ICRP Reference Man). Organ contents for these elements were also calculated by applying the new ICRP models of these elements to their daily intakes. The comparison of the calculated and measured organ contents showed that despite uncertainties in the organ content values arising due to the inter-country variations in daily dietary intakes, the contents were within a factor of two to three. This observation is significant since human data both on organ contents and ingestion were obtained at environmental level of intakes. The study suggests that currently available ICRP models for these elements are quite realistic.

Adult↗
PubMed1987

Strontium kinetics in metastasized prostatic carcinoma: a comparison with the predictions of impulse response function analysis.

Amongst patients referred for 89Sr palliation of disseminated prostatic carcinoma, we have found wide variations in extent of skeletal metastatic disease and in strontium renal plasma clearance. A numerical technique using impulse response function analysis is reviewed which enables the effect of such variations on the total body, plasma and metastatic strontium retention functions to be calculated. The prediction of the model are compared with kinetic data from patients presenting for radiostrontium therapy, and correlations that have important implications for 89Sr dosimetric studies are confirmed. The simplest kinetic data required to allow for these effects in studies of dose-response and haematological toxicity following radio-strontium treatment are discussed and attention is drawn to a small group of patients who may form a significant exception to the general model.

Bone Neoplasms↗
PubMedDate not supplied

Combined keratectomy, strontium-90 irradiation and permanent bulbar conjunctival grafts for corneolimbal squamous cell carcinomas in horses (1990-2002): 38 horses.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of postoperative beta-irradiation with strontium-90 as an adjunctive treatment to superficial keratectomy and permanent bulbar conjunctival graft for removal of equine corneolimbal squamous cell carcinoma (SCC), in decreasing recurrence rate. STUDY: The retrospective case study included 38 horses diagnosed and treated for SCC of the eye that involved the limbus and/or cornea. The patients were treated between 1990 and 2002, with strontium-90 irradiation immediately after corneal and conjunctival graft surgery. Recurrence was defined as the postoperative and postirradiation regrowth of SCC in the same site and globe that was previously treated. RESULTS: The Appaloosa was the most commonly represented breed and horses that had more than one base coat color represented the majority of the cases (53%). The coat colors of white, chestnut/sorrel and gray were the most commonly represented colors of the horses treated. Eight horses (21%) could not be assessed for tumor recurrence due to lack of two or more post-treatment examinations, and another horse was enucleated 6 days postoperatively due to progressive corneal ulceration. Twenty-four horses (63% of the entire study population; 83% of the followed cases) had a mean +/- SD of 1754 +/- 1319 days without tumor recurrence, ranging from 14 days to 5110 days. Five horses (13% of the entire study population; 17% of the assessed horses) had tumor recurrence at a mean +/- SD of 449 +/- 339 days with a range of 29 days to 900 days. For the five recurrences, treatment included local excision (n = 1), enucleation (n = 2), and additional strontium-90 therapy (n = 3). CONCLUSIONS: The combination of superficial keratectomy, beta-irradiation and permanent bulbar conjunctival grafts for limbal, corneal or corneolimbal SCC in horses is effective in at least 83% of the horses. Recurrence occurred in about 17% of the horses. Multiple biannual re-examinations are recommended to observe for tumor recurrence.

Animals↗
PubMed2006

Multiple limbal haemangiosarcomas in a border collie dog: management by lamellar keratectomy/sclerectomy and strontium-90 beta plesiotherapy.

An eight-year-old, neutered, male border collie dog was presented with a six-week history of left ocular discomfort and a raised, red mass at the lateral limbus. The right eye had been enucleated approximately 12 months previously following suspected trauma when the eye had become red and painful. The mass was excised using superficial keratectomy/sclerectomy and the surgery site was treated with strontium-90 beta radiation. Histopathological findings were consistent with a diagnosis of haemangiosarcoma. Immunohistochemical staining showed uniform expression of CD31 in neoplastic cells, confirming their endothelial origin. Two further treatments with strontium-90 beta radiation were applied to the surgical site at weekly intervals. Twenty-six weeks after surgery, a second, raised, red limbal mass became apparent at the medial limbus of the left eye. Surgical excision and adjuvant strontium-90 beta plesiotherapy were performed as described for the initial tumour. Routine histopathological analysis confirmed haemangiosarcoma at this site. Eighty-six weeks following the initial presentation, no recurrence of ocular haemangiosarcoma was evident.

Animals↗
PubMed1966

Strontium incorporation into dental enamel.

Rats were raised on diets either rich or poor in strontium. Powder x-ray diffraction patterns suggest that isomorphous substitution of strontium for calcium occurs in the apatite of tooth enamel, and that strontium may form Sr(6)H(3)(PO(4)) * 2H(2)O, a compound hitherto unreported in biologic systems.

Animals↗
PubMed1967

Strontium-90 deposition in New York City.

Measurements of strontium-90 deposited in New York City over the past 12 years make for broader understanding of the fallout phenomenon. The data indicate a stratospheric half-residence time of 8 to 10 months. The seasonal oscillation of strontium-90 fallout is very symmetrical and consistent from year to year and completely independent of the timing and magnitude of nuclear tests. The predicted fallout of strontium-90 in 1970 is less than 1 percent of that during the peak year 1963.

History, 20th Century↗
PubMed1971

Strontium induced rickets: metabolic basis.

Dietary strontium inhibits both the synthesis of 1,25-dihydroxycholecalciferol and intestinal calcium absorption in vitamin D(3)-repleted chicks. 1,25-Dihydroxycholecalciferol restores calcium absorption to normal, while 25-hydroxycholecalciferol is without effect in the strontium-fed chick. It is suggested that strontium induces rickets by blocking the biosynthesis of 1,25-dihydroxycholecalciferol, the metabolically active form of vitamin D in the intestine.

Animals↗
PubMed1974

Calcium absorption and calcium-binding protein synthesis: solanum malacoxylon reverses strontium inhibition.

The ingestion of diets containing high concentrations of stable strontium inhibits calcium absorption and intestinal calcium-binding protein synthesis and, as shown by others, does so by inhibiting the conversion of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol, the active form of vitamin D. The addition of the South American plant Solanum malacoxylon to strontium-containing diets counteracts the inhibitory action of dietary strontium, thereby indicating that the plant contains a factor which can mimic the action of 1,25-dihydroxycholecalciferol and representing the first such factor identified in a botanical source.

Animals↗
PubMed1996

Rickets and soil strontium.

The subjects of this study were children aged 6-60 months living in villages in the Ulas Health Region, Sivas. The villages were divided into two groups according to the amount of strontium in the soil: region 1, > 350 ppm, 650 children; region 2, < 350 ppm, 1596 children. Overall, the prevalence of one or more clinical signs of rickets was 22.9%. The prevalence in region 1 was 31.5% and that in region 2, 19.5%. These values were significantly different (p < 0.001). When other variables which may be relevant to the occurrence of rickets were taken into account, the difference in prevalence persisted. The results suggest that in villages where nutrition is mainly based on grain cereals the presence of strontium in the soil will increase the prevalence of rickets significantly. As a preventive measure, a greater proportion of the foods given to children in these villages should be derived from animal origin, and cereals and drinking water supplies should be obtained from villages with a low soil strontium content, or calcium supplements should be given.

Age Distribution↗
PubMed1991

Effects of fluoride, lithium, and strontium on growth and acid production of mutants streptococci and Actinomyces viscosus.

Eight strains of mutants streptococci and two strains of Actinomyces viscosus were studied to determine (1) their relative sensitivities to fluoride, lithium, and strontium and (2) whether lithium or strontium interact to enhance the known antimicrobial effects of fluoride. Analyses of variance of the data revealed a major inhibition of growth and acid production by fluoride, but not by lithium or strontium. Fluoride (5 mg/l) inhibited cell growth of all strains tested by a mean of 17% and total titratable acid production by a mean of 31%. However, there were marked differences between the strains. Mean total titratable acid was inhibited by fluoride least with the A. viscosus strains (15%) and most with the mutans streptococci (34%). Although interactions among the elements were statistically significant, they were generally slight in magnitude.

Acids↗
PubMed1984

Effects of fluoride, lithium, and strontium on intracellular polysaccharide accumulation in S. mutans and A. viscosus.

Fluoride (5 mg/l) consistently depressed the accumulation of intracellular iodophilic polysaccharides (IPS) in Streptococcus mutans strains BHT, FA-1, and GS-5 by over 90% and in Actinomyces viscosus strain RC-45 by over 50%. There was little further reduction in IPS content when fluoride was increased from 5 to 100 mg/l. Lithium (0 to 1 mg/l) neither enhanced nor inhibited IPS accumulation, nor did it modify the inhibitory effects of fluoride in three of the four strains tested. Strontium (0 to 100 mg/l) did not alter IPS accumulation in S. mutans GS-5 but decreased accumulation (less than 10%) in S. mutans FA-1 and BHT and significantly enhanced IPS accumulation in A. viscosus RC-45. Analysis of variance indicated no statistically significant interactions between fluoride and strontium, fluoride and lithium, or strontium and lithium.

Actinomyces↗
PubMed2006

Effects of strontium on bone strength, density, volume, and microarchitecture in laying hens.

UNLABELLED: Strontium has been reported to have beneficial effects on bone. Treatment of laying hens, which are susceptible to osteoporosis and bone fracture, with strontium increased DXA measurements of BMD and BMC and microCT measurements of bone volume and microarchitecture and improved the mechanical performance of whole bone, but had no effect on the estimated material properties of the bone tissue. INTRODUCTION: Strontium (Sr) has been reported to dissociate bone remodeling and have positive influences on bone formation. We supplemented the diet of laying hens, which are susceptible to osteoporosis and bone fracture, with Sr to study the capacity of the element to improve bone mechanical integrity and resistance to fracture. MATERIALS AND METHODS: Increasing dosages of Sr (0, 3000, 4500, and 6000 ppm) were fed to 196 13-week-old pullets for 11 months. BMD and BMC, as measured by conventional and DXA methods, microarchitectural parameters derived from microCT, and structural and material properties as determined by three-point bending test, were studied. Calcium (Ca), phosphorus (P), and Sr levels in plasma and bone, as well as egg output, shell quality, and composition, were assessed. RESULTS: Sr concentrations in plasma and bone increased in a dose-dependent manner without affecting Ca and P. Treatment with Sr increased BMD and BMC as measured by DXA, increased cortical and medullary bone volume, trabecular thickness, number, and surface, and improved whole bone ultimate load, but had no effect on the estimated material properties of diaphyseal bone. Sr also increased the ash content of eggshells and did not affect egg output and shell quality. CONCLUSIONS: Sr supplementation induced large positive effects on bone density, volume, and microarchitecture as measured by radiographic methods. Sr treatment also improved the structural strength of diaphyseal bone but had no effect on the estimated material properties of the bone tissue.

Animals↗
PubMed1991

Rapid effects of parathyroid hormone(1-34) and prostaglandin E2 on bone blood flow and strontium clearance in the rat in vivo.

The vascular effects of noradrenaline, ATP, parathyroid hormone (PTH) and prostaglandin E2 (PGE2) were investigated in the rat. Additionally, the exchange of mineral ions between bone and blood was assessed by measuring strontium clearance, with the aim of investigating whether the vascular effects of these agents altered uptake of mineral ions or if this exchange could be changed independently of blood flow. Radioactive microspheres and 85Sr were used to establish bone blood flow and mineral clearance. Measurements of bone blood flow and arterial pressure were made in each animal and used to calculate vascular resistance. A measurement of 85Sr clearance was also obtained. Arterial blood pressure was significantly affected by noradrenaline (P less than or equal to 0.003) and ATP (P less than or equal to 0.015). Additionally, noradrenaline significantly (P less than or equal to 0.03) reduced bone blood flow. This decrease was related to a significant increase in vascular resistance. Arterial blood pressure and bone blood flow were significantly reduced by both bovine PTH(1-34) (P less than or equal to 0.001, P less than or equal to 0.02) and PGE2 (P less than or equal to 0.005, P less than or equal to 0.001). Vascular resistance to bone was increased by both agents but this was only statistically significant in the case of PGE2 (P less than or equal to 0.01). A significant (P less than or equal to 0.001) reduction in strontium was also produced by PGE2. In each group the relationship between bone blood flow and strontium clearance was then analysed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1987

Efficacy of strontium chloride in dental hypersensitivity.

Controlled stimuli were used to evaluate a commercially available dentifrice containing 10% strontium chloride hexahydrate for efficacy in alleviating the symptoms of uncomplicated dentinal hypersensitivity. Sixty-one subjects with hypersensitivity were included in the 12-week, double-blind, parallel, comparative (placebo) study. Levels of hypersensitivity in affected teeth were assessed by three methods: thermally controlled cold air stimulus, tactile stimulus with an electronic pressure sensitive probe, and subjective response. The results from all three methods of assessment indicated that the strontium chloride dentifrice, in comparison with a placebo, reduced dentinal hypersensitivity to a significantly greater degree. This therapeutic response to the active agent was apparent within 2 weeks and increased continuously thereafter for the length of the study. One can conclude that the regular at-home use of a dentifrice containing 10% strontium chloride hexahydrate is an effective means for reducing the discomfort and pain engendered by thermal and tactile stimuli in patients with dentinal hypersensitivity.

Adolescent↗
PubMed1994

Dentine hypersensitivity: a clinical trial to compare 2 strontium densensitizing toothpastes with a conventional fluoride toothpaste.

A considerable number of varied agents are apparently effective in the treatment of dentine hypersensitivity. In particular, the literature supports the efficacy of fluoride and strontium containing formulations. Despite this, comparisons between strontium products are relatively few in number and surprisingly there are almost no evaluations of these products against "bench mark," conventional commercial fluoride toothpastes. This study was a double-blind parallel group comparison of two strontium-based desensitizing toothpaste products and a conventional fluoride product in the treatment of dentine hypersensitivity. A total of 119 patients completed the 12-week study and from them, sensitivity gradings were obtained at baseline, 1, 4, 8, and 12 weeks. Sensitivity was scored in response to cold air, a thermal probe at 0 degree C, and scratching with a dental probe. Patients also graded their overall sensitivity at each visit, using a visual analogue scale and the effects of treatment on completion. Plaque and gingivitis indices were recorded at each visit. There was an overall and progressive reduction in all sensitivity parameters in the 3 groups with no significant differences between the treatments. Plaque and gingivitis scores were already relatively low in this patient group at baseline but improved further as the study continued. The improvements, however, were comparable in the 3 groups. Under the conditions of this clinical trial the 2 desensitizing toothpastes showed similar reductions, but no greater than that observed in the conventional fluoride toothpaste. There is perhaps the need for further evaluations of desensitizing formulations using conventional fluoride products as controls rather than minus active or placebo formulations.

Adult↗