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PubMed2005

The long-term environmental behaviour of strontium and barium released from former mine workings in the granites of the Sunart region of Scotland, UK.

The concentrations of strontium and barium have been measured in water, sediment and the shells of mussels (Mytilus edulis) from a river system in the Sunart region of Scotland, UK. The aim was to establish the fate and mobility of these elements, which are slowly being released from old mine workings on the Strontian granites. Enhanced strontium (1500-2000 microg l(-1) and 250-290 microg l(-1)) and barium concentrations (316 microg l(-1) and 83 microg l(-1)) were found in the waters originating from the two mine drains studied. Both element were also found at significant levels in the river sediments taken from the vicinity of each drainage site (Sr: 225 microg g(-1) and 120-125 microg g(-1); Ba: 1380 microg g(-1) and 126-170 microg g(-1)). The data suggests that the sediments are acting as a reservoir for these group II cations from where they become distributed throughout the river system. Strontium is found to be incorporated into the shells (3.16-3.46 microg g(-1)) and pearls (3.57 microg g(-1)) of the blue mussel, located at the estuarine margin some 10 km downstream, at values close to the maximum expected (3.3% by weight of the calcium content). The study presents a view of the fate of barium and strontium in a river system over a prolonged period of time. As such it provides valuable information for studies that seek to model the impact of the accidental release of barium and strontium (including the important radionuclide 90Sr) into the environment.

Animals↗
PubMed2000

Strontium nitrate suppresses chemically-induced sensory irritation in humans.

Skin care products are complex formulations that may cause sensory irritation symptoms, characterized by stinging, burning, and itching. Substances capable of counteracting sensory irritation are of great practical interest. Strontium salts have been demonstrated to inhibit sensory irritation and inflammation when applied topically. In this double-blind study, we evaluated the efficacy of strontium nitrate in reducing chemically-induced skin sensory irritation in 8 subjects. In a random order, 20% strontium nitrate in 70% glycolic acid (pH=0.6) (mixture) was applied to the volar aspect of the forearm and a positive control (70% glycolic acid, pH=0.6) to the contralateral forearm. The irritation sensation was evaluated each min for the first 20 min after topical application using a scale from 0-4. The duration of the irritation sensation in min was also recorded. Strontium nitrate mixed with glycolic acid, in comparison with glycolic acid alone, markedly (p<0.01) shortened the duration of the irritation sensation from 24.4+/-4.1 (mean+/-SEM) min to 8.9+/-3.7 (mean+/-SEM) min, and significantly (p<0.05) reduced the mean magnitude of the irritation sensation at all time points (overall). The study demonstrated that strontium nitrate potently suppresses the sensation of chemically-induced irritation.

Adult↗
PubMed1982

The in situ measurement of strontium content in bone using x-ray fluorescence analysis.

A technique is described which uses x-ray fluorescence to determine in situ the strontium content of bone. Measurements were made of the skulls of seven rabbits both before and after a single bolus injection of strontium was administered intravenously. The retention of strontium was followed for up to eight months and could be represented either by a three-exponential model or, for data obtained between 12 and 252 d following injection, the power function At-b, where t is the time in days following injection. The three-exponential terms had linear coefficients of similar magnitude and half lives of 3-4 h, 10-40 d and 200-300 d. The exponent of the power function was 0.25-0.57. Measurements were also made of the skull and medial surface of the tibial crest of an adult dog for four months following subcutaneous administration of strontium. The results obtained using x-ray fluorescence are found to be similar to those reported by others for radiostrontium studies. The precision and errors associated with the fluorescence technique are discussed. Estimates of radiation dose are given. It is concluded that the technique may serve to determine in situ the strontium content of bone near the surface of the body.

Animals↗
PubMed2002

Absorption of strontium from the gastrointestinal tract into plasma in healthy human adults.

The radioactive isotopes of strontium have always been a major concern in radiation protection. Currently, radiostrontium is of interest for evaluation of the health effects of the Chernobyl accident and for epidemiological studies in populations exposed to releases from the Mayak nuclear facilities in Russia. Ingestion is one of the most important exposure pathways involving radioactive strontium. The main sources of published data on the fraction of the ingested strontium that is transferred to plasma (f1) are summarized. For some of these studies, the original data had to be reanalyzed and a new iterative method to account for the elimination in feces of strontium of endogenous origin (i.e., that was absorbed to blood and has already been returned into feces) was employed. Data indicate no significant dependence of the absorbed fraction on sex or age at exposure within the adult group, but absorption of strontium is reduced if the intake of stable calcium is very high and is enhanced if the intake of calcium is very low. The probability distribution function of f1 values is well represented by a lognormal curve with a geometric mean of 22.3% and a geometric standard deviation of 1.44 (95% confidence interval 10.9% to 45.6%, or about a factor of 2 around the geometric mean). This distribution can be considered representative for the variability of the f1 values in a population of healthy adults.

Administration, Oral↗
PubMed1991

Activation and binding volumes of the sarcoplasmic reticulum transport enzyme activated by calcium or strontium.

The effect of pressure on the hydrolysis of dinitrophenyl phosphate (DnpP) and p-nitrophenyl phosphate (NpP) by the sarcoplasmatic reticulum transport enzyme in permeabilized and native closed vesicles activated by calcium or strontium, respectively, in aqueous and Me2SO-containing media has been studied. At atmospheric pressure, the enzyme in permeabilized vesicles, saturated with respect to substrates and activating ions, hydrolyzes DnpP ten times faster than NpP; for both substrates, calcium activation exceeds that by strontium only a little (20%). In aqueous media the enzyme displays, under all activating conditions, an almost identical curvilinear relationship between the logarithm of enzyme activity and pressure. The data were analysed on the basis of a simplified reaction scheme, in which two unidirectionally proceeding substrate-driven pressure-dependent reactions (k2, k4) cyclically transfer high-affinity into low-affinity binding sites which are assumed to be in equilibrium with either calcium or strontium. The fitting procedure yielded two sets of positive activation volumes delta V2* = 90-110 ml/mol and delta V4* = 15-25 ml/mol. Substrate specificity, as well as the effect of temperature, are exclusively localized in the pressure-independent rate constants k'2 and k'4. Considerable different pressure/activity relations characterized by a single activation volume of 20 ml/mol were obtained for the strongly suppressed substrate hydrolysis of native closed vesicles. At atmospheric pressure DnpP hydrolysis of open vesicles is inhibited by Me2SO, while NpP hydrolysis is considerably activated, irrespective of its activation by calcium or strontium. In the presence of 22.5% Me2SO, the activation volumes are reduced by 50-70 ml/mol. The rate constants of DnpP and NpP hydrolysis are either augmented or reduced by rising Me2SO concentrations, depending on the corresponding supporting substrate. Me2SO has only a slight effect on the pressure dependence of substrate hydrolysis by native vesicles. The small activation volume observed for the activity of native vesicles could be assigned on account of the simplified reaction scheme of the slow reaction step k4, by which the enzyme is transferred from its low-affinity into its high-affinity binding state. Volume changes connected with the binding of calcium or strontium to the luminal binding site of the enzyme were deduced from the observed activation volume and the computed volume change of the slow reaction step (delta V4*).

Animals↗
PubMed2006

Massive strontium ferrite ingestion without acute toxicity.

Ingestion of strontium ferrite is previously unreported. We document absorption of strontium without acute toxicity. A 22 year-old schizophrenic man was brought to hospital after he was witnessed to pulverize and ingest flexible adhesive magnets, which later were identified as strontium ferrite. Other than auditory hallucinations his vital signs, physical examination, ECG and routine laboratories were unremarkable. Abdominal radiographs revealed diffuse radiopaque material. He was treated with whole bowel irrigation with polyethylene glycol electrolyte lavage solution (PEG-ELS) until radiographically cleared. His initial blood and urine strontium levels were 2900 microg/l and 15,000 microg/l, respectively (reference range for urine: <240 microg/l, occupational threshold 800 microg/l). A repeat urine level one week later was 370 microg/l. His hospital course was complicated by bacteraemia secondary to a thrombophlebitis at the site of the intravenous catheter, and the patient was treated with intravenous and oral antibiotics. He remained otherwise asymptomatic and was discharged to a psychiatric unit approximately 3 weeks later. Although clearly absorbed, strontium ferrite does not appear to produce acute toxicity. Delayed, and or chronic toxicity cannot be excluded based on this report.

Adult↗
PubMed1973

The interaction of calcium and strontium with phosphatidyl serine in the anaphylactic secretion of histamine.

1. Spontaneous histamine release from isolated mast cells was found to be independent of calcium in the concentration range up to 1 m-mole/l. Phosphatidyl serine did not change the effect of calcium on spontaneous release.2. Spontaneous histamine release was found to vary with the strontium ion concentration. Graded increase in the release occurred as the concentration of strontium was raised from 1 to 10 m-mole/l. Phosphatidyl serine potentiated this action of strontium; the potentiation showed a graded increase as the phosphatidyl serine concentration was raised from 1 to 100 mug/ml.3. The activation of anaphylactic histamine release by calcium was potentiated by phosphatidyl serine; the degree of potentiation showed a graded increase as the calcium concentration was raised from 0.1 to 1.0 m-mole/l.4. The activation of anaphylactic histamine release by strontium showed little, if any, potentiation by phosphatidyl serine.5. The response of the mast cells, in terms of anaphylactic histamine release, to calcium, in the presence of optimal concentrations of phosphatidyl serine, was found to be similar to that observed in the presence of strontium alone.6. These observations are discussed in terms of the concepts of affinity and efficacy of the ions at their receptor sites.

Anaphylaxis↗
PubMed1966

Precipitate formation in the strontium-phosphate system.

Study of the precipitation process in the aqueous Sr(OH)(2)-H(3)PO(4) system, in order to elucidate the phase transformations and the nature of the final solid phases, shows that over much of the range of compositions studied the initial precipitate is poorly crystalline; the x-ray pattern resembles that of strontium hydroxyapatite but has a strontium: phosphorus molar ratio close to 1.3. Within 1 hour the initial precipitate changes to a stable crystalline phase (or phases), with corresponding change, either up or down, in the strontium: phosphorus ratio. At high ratios of Sr(OH)(2) to H(2)PO(4) the initial precipitate is Sr(3)(PO(4))(2)-4H(2)O, which then converts to a phase having the x-ray diffraction pattern of strontium hydroxyapatite, but having a strontium: phosphorus ratio that depends somewhat on the initial ratio of Sr(OH)(2) to H(3)PO(4) used in the precipitation.

Apatites↗
PubMed1972

Further study of strontium selenite and selenite F broths for the isolation of Salmonella typhi.

The efficiency of strontium selenite and selenite F broths in the isolation of S. typhi from 625 clinical stool specimens were compared. A total of 126 strains of S. typhi were detected. Of these, 96 (76%) were isolated with selenite F broth and 118 (94%) were isolated with strontium selenite broth. At the same time, the number of false positive isolates accruing to strontium selenite broth was less than that accruing to selenite F broth. The superiority of strontium selenite broth over selenite F broth was more obvious when relatively few typhoid bacilli were present in faeces, eg, after antibiotic therapy, or when stools had been left for prolonged periods at room termperature. In the isolation of S. typhi with strontium selenite broth, salmonella-shigella agar was found to be a better plating medium than xylose lysine desoxycholate agar.

Agar↗
PubMed1976

Effect of strontium on the epiphyseal cartilage plate of rat tibiae-histological and radiographic studies.

Following dietary administration of strontium carbonate, histological and radiographic changes in the epiphyseal cartilage plate of the rat tibiae were examined in the present study. The weight gain of the rat fed a strontium diet was less than that of the control rats. Longitudinal growth of tibiae and endochondral ossification were inhibited by strontium administration. The widths of both proximal and distal cartilage plates increased enormously as has also been shown by other investigators. Sizes of chondroblasts in columns of proximal cartilage plate in rats fed a strontium diet were smaller than those of the control rats and were not different between upper and lower parts. It is suggested that strontium inhibits bone growth through the inhibitory action on the maturation process of chondroblasts and the succeeding endochondral ossification.

Animals↗
PubMed1987

Strontium-89 radionuclide therapy: a dosimetric study using impulse response function analysis.

In a series of patients receiving 89Sr palliation for metastasised prostatic carcinoma, strontium renal plasma clearance was found to vary from 0.14 to 11.81 day-1, and the extent of skeletal metastatic disease seen on 99Tcm-MDP images varied from a few small metastases to a superscan. Using a numerical technique based on impulse response function (IRF) analysis, we have investigated the effect of such variation between patients on 89Sr dosimetry. The whole-body IRF, HWB(t), is defined by the deconvolution of the whole-body strontium retention function, RWB(t), with the plasma retention function, P(t). For patients with minimal metastatic bone disease we assumed HWB(t) = HO(t), where HO is the IRF derived from the International Commission on Radiological Protection model for normal strontium metabolism. The strontium plasma clearance, k, was allowed to vary, and the resulting variation of RWB(t), P(t) and absorbed dose to bone marrow calculated. By convoluting P(t,k) with the IRF measured for a discrete metastasis, the effect of varying k on tumour dose was investigated. Tumour and bone marrow dose were shown to change by a factor of three as k varied over the range observed in patients. For patients with extensive metastatic bone disease we assumed HWB(t) = (1-beta)HO(t) + beta HS(t), where HS was the IRF measured for a superscan patient and beta was a parameter reflecting the extent of skeletal metastatic disease. The effect of varying beta on tumour and bone marrow dose was investigated, and dose shown to decrease by a factor of five as beta increased from zero to unity. Impulse response function analysis was found to be a powerful and useful aid in clarifying the relationship between strontium kinetics and 89Sr dosimetry.

Bone Marrow↗
PubMed1975

Strontium-85 profile counting in fractures of the tibial shaft.

A total of 203 profile countings were performed on 68 fractures of the tibial shaft, which included 25 normally healing cases, 37 cases of delayed union, and six cases of non-union. The measurements were performed on the 1st and the 7th day after the injection of strontium. In 27 cases the fracture received 2-3 strontium injections with associated profile counting at different stages of the healing process. The cases of normally healing fractures and delayed union showed differences in the average strontium uptake. However, these differences were not distinct enough to enable classification of individual fractures into groups. In cases requiring bone grafting, the transplant was found to accelerate metabolism and increase the accretion of strontium at the site of the fracture. The investigation shows that the real value of strontium profile counting lies in its ability to give information about the osteogenetic activity of the bone, which is a necessary prerequisite for the healing of the fracture.

Bone Transplantation↗
PubMedDate not supplied

Strontium fallout from Chernobyl and perinatal mortality in Ukraine and Belarus.

Perinatal mortality rates in the regions of Ukraine and Belarus surrounding the Chernobyl site increased in 1987, the year following the Chernobyl accident. The same year, increases of perinatal mortality were also observed in Germany and Poland, and the effect can be associated with the caesium burden in pregnant women. After 1989, there is an unexpected second rise of perinatal mortality in Belarus and Ukraine. This increase is shown to correlate with the strontium content in pregnant women. The findings parallel an increase of perinatal mortality in Germany following the atmospheric bomb tests in the 1950's and 1960's. While the effect from caesium is essentially limited to 1987, the effect from strontium persists until the end of the study period in 1998. The cumulative effect from strontium around Chernobyl outweighs the effect from caesium by at least a factor of 10. This is contrary to the assertion that the caesium content in the Chernobyl fallout was more than 10-times greater than the strontium content. Thus, the dose factor presently used seems to severely underestimate the effect of strontium on perinatal mortality.

Fetal Death↗
PubMed1992

Dose estimation in strontium-89 radiotherapy of metastatic prostatic carcinoma.

Strontium-89 radiotherapy is becoming an important treatment in the palliation of bone pain from osteoblastic metastases. The absorbed dose delivered to bone metastases during 89Sr radiotherapy has been estimated in four patients with metastatic prostatic carcinoma. Patients were injected with a tracer dose of 85Sr-chloride. Blood and urine samples were obtained during the week following injection. Strontium-85 scintigrams of metastases and normal bone were obtained up to 8 wk postinjection. Half of the patients showed elevated whole-body retention; plasma-strontium concentrations were decreased from normal values. Uptake of strontium in metastases was 2-25 times that in normal bone but rates of washout of strontium from metastases were similar to those from normal bone. Absorbed doses delivered in infinite time to the metastases by 89Sr ranged from 21 +/- 4 to 231 +/- 56 cGy/MBq with a median value of 68 cGy/MBq. Doses to red marrow were less by a factor of 2 to 50. These absorbed doses are sufficiently large to be expected to produce a therapeutic benefit.

Bone Neoplasms↗
PubMed1989

Strontium and bromide as tracers in X-ray microanalysis of biological tissue.

Since energy dispersive X-ray microanalysis cannot distinguish between isotopes of the same element, alternative methods have to be used to get information similar to that obtained in experiments with radioactive tracers. In the present study, strontium was used as a tracer for calcium, and bromide as a tracer for chloride. Rats were injected with strontium chloride in vivo, and the uptake of strontium in the acinar cells of the submandibular gland was studied. Eventually a Sr/Ca ratio of 0.3 was reached. In some animals, secretion of mucus had been elicited by stimulation with isoproterenol 4 h prior to injection of strontium chloride. Exchange of calcium for strontium was enhanced by prior injection with isoproterenol. In a second experiment, rats were injected with sodium bromide, and the uptake of bromide by the submandibular acinar cells was followed in time, both in pilocarpine-stimulated and unstimulated glands. Under the experimental conditions, bromide was rapidly taken up by the cells, and the cellular Br/Cl ratio was close to that found in serum. Submandibular glands take up Br somewhat faster than other tissues (liver, heart muscle, skeletal muscle). The uptake of Br in pancreatic acinar cells was studied in vitro. These experiments showed a 1:1 ratio (molar) exchange of Cl for Br.

Animals↗
PubMedDate not supplied

[Effect of strontium on the anti-rickets activity of vitamin D3 and its hydroxy analogs].

Antirickets activity of vitamin D3 and of its derivatives 1 alpha- and 25-hydroxy vitamin D3 1.25- and 24,25-dihydroxy vitamin D3 and 1,24,25-trihydroxy vitamin D3 was studied in chicken maintained on a diet containing various amount (0.01-2.40 mg) of strontium. Vitamin D3 as well as its 24-hydroxy and 24,25-dihydroxy derivatives lost their antirickets activity in presence of high strontium concentrations. Under the same conditions I alpha-hydroxy, 1,25-dihydroxy and 1,24,25-trihydroxy vitamins D3 retained the ability both to induce calcium-binding protein synthesis in intestinal epithelium and to stimulate bone tissue mineralization, although to a lesser degree as compared with controls, kept on strontium-free diet. These results suggest that presence of I alpha-OH-group in the steroid molecule is necessary for expression of maximal biological activity under conditions of elevated strontium content in diet while the activity of hydroxylase is inhibited in kidney. At the same time, the vitamin D3 derivatives containing the OH-group are responsible for impairments caused by increased accumulation of strontium.

24,25-Dihydroxyvitamin D 3↗
PubMed1979

Surgical and strontium treatment of pterygium: recurrence and lens changes. Age statistics.

The results of a study of 975 pterygia treated surgically and immediately with Strontium 90 are presented. The recurrence rate (quiescent) was 6%. The actual recurrence requiring surgery was 0.82%. Technique of removal involves simple wide excision and immediate treatment with Strontium 90 over the entire area. Three thousand RADS is the maximum dosage. In most instances more than 3000 RADS is cataractogenic. Two methods of Strontium 90 production are discussed. Strontium 90 has a half life of 19.9 plus or minus .3 years. It decomposes to Yttrium 90 which has a half life of 62 hours. Tissue penetration is estimated by the use of polystyrene absorber which is considered to be a tissue equivalent. Age and sex occurrence is given from a survey of 832 patients. Newer developments that might replace Strontium 90 are briefly discussed.

Adult↗
PubMed1984

Elevated granulocyte strontium in inflammatory arthritides is related to the inflammatory activity.

Total cellular strontium and calcium were measured by the nuclear microprobe technique. Increased mass fraction of both elements was found in granulocytes isolated from patients with active rheumatoid arthritis and other kinds of inflammatory arthritides. Increased granulocyte calcium but only marginally elevated granulocyte strontium was demonstrated in patients with scleroderma. The granulocyte accumulation of strontium and calcium seems to be linked to the degree of inflammatory activity, because the granulocyte content of both elements was positively correlated to the plasma concentration of acute-phase proteins. Corticosteroid therapy induced a marked reduction of granulocyte strontium but a more modest decrease of granulocyte calcium. The serum levels of strontium and calcium were within the normal ranges in all patients and were not significantly altered by corticosteroids.

Adolescent↗