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The behavior of nanoparticles released to the soil has been extensively studied in recent years; however, the effects of nanoparticles on the distribution of soil elements and on sowing are still unknown. To this end, to examine the distribution of selected elements in soil, soil samples were treated weekly with 1.0 mg and 20.0 mg of Al 2 O 3 nanoparticles for 3 weeks. Additionally, different types of plants (including taproot, fibrous root and ornamental bulbous plants) were sowed in the soil samples. After each treatment, surface soil samples were collected and digested with acid digestion. The concentrations of selected elements (Ca, Mg, Fe, Al, Cu, Co, Ni) were determined using a microwave plasma atomic emission spectrometer. Al 2 O 3 treatment for 3 weeks, both low and high doses, had no effect on the Al content in soil samples when compared to the controls. Additionally, Al 2 O 3 showed desorption properties on the analyte elements.

The aim of this study was to investigate the effects of balneotherapy on chronic low back pain. This is a minimized, follow-up study evaluated according to the analysis of intention to treat. The subjects included in the study were 105 patients suffering from chronic low back pain. The control group (n = 53) received the traditional musculoskeletal pain killer treatment, while the target group (n = 52) attended thermal mineral water treatment for 3 weeks for 15 occasions on top of the usual musculoskeletal pain killer treatment. The following parameters were measured before, right after, and 9 weeks after the 3-week therapy: the level of low back pain in rest and the level during activity are tested using the Visual Analog Scale (VAS); specific questionnaire on the back pain (Oswestry); and a questionnaire on quality of life (EuroQual-5D). All of the investigated parameters improved significantly (p < 0.001) in the target group by the end of the treatment compared to the base period, and this improvement was persistent during the follow-up period. There were no significant changes in the measured parameters in the control group. Based on our results, balneotherapy might have favorable impact on the clinical parameters and quality of life of patients suffering from chronic low back pain.

Magnesite is the world's most important source material for magnesia refractory production, and Haicheng City in Liaoning Province, China has been called "the magnesium capital of the world." However, magnesite mining in these areas has caused serious environmental problems. Field investigations have shown that the soil profile of many sites in the mining region are contaminated by magnesium, and the magnesium-enriched crusts that have formed on the soil surface have affected ecologically important soil functions, particularly reduced water penetration rate. Laboratory experiment revealed that anionic polyacrylamide and calcium dihydrogen phosphate can be used to improve soil condition, and have positive effects on soil function. The findings of this study are of significance in the magnetite mining areas, providing clear options for the remediation of soils that should be carried out immediately.

Many butterflies acquire nutrients from non-nectar sources such as puddles. To better understand how male Papilio butterflies identify suitable sites for puddling, we used behavioral and electrophysiological methods to examine the responses of Japanese Papilio butterflies to Na(+), K(+), Ca(2+), and Mg(2+). Based on behavioral analyses, these butterflies preferred a 10-mM Na(+) solution to K(+), Ca(2+), and Mg(2+) solutions of the same concentration and among a tested range of 1 mM to 1 M NaCl. We also measured the ion concentrations of solutions sampled from puddling sites in the field. Na(+) concentrations of the samples were up to 6 mM, slightly lower than that preferred by butterflies in the behavioral experiments. Butterflies that sipped the 10 mM Na(+) solution from the experimental trays did not continue to puddle on the ground. Additionally, butterflies puddled at sites where the concentrations of K(+), Ca(2+), and/or Mg(2+) were higher than that of Na(+). This suggests that K(+), Ca(2+), and Mg(2+) do not interfere with the detection of Na(+) by the Papilio butterfly. Using an electrophysiological method, tip recordings, receptor neurons in contact chemosensilla inside the proboscis evoked regularly firing impulses to 1, 10, and 100 mM NaCl solutions but not to CaCl(2) or MgCl(2). The dose-response patterns to the NaCl solutions were different among the neurons, which were classified into three types. These results showed that Japanese Papilio butterflies puddle using Na(+) detected by the contact chemosensilla in the proboscis, which measure its concentration.

Fungal activity is thought to play a direct and effective role in the breakdown and dissolution of primary minerals and in the synthesis of clay minerals in soil environments, with important consequences for plant growth and ecosystem functioning. We have studied primary mineral weathering in volcanic soils developed on trachydacite in southern Tuscany using a combination of qualitative and quantitative mineralogical and microbiological techniques. Specifically, we characterized the weathering and microbiological colonization of the magnetically separated ferromagnesian minerals (biotite and orthopyroxene) and non-ferromagnesian constituents (K-feldspar and volcanic glass) of the coarse sand fraction (250-1,000 microm). Our results show that in the basal horizons of the soils, the ferromagnesian minerals are much more intensively colonized by microorganisms than K-feldspar and glass, but that the composition of the microbial communities living on the two mineral fractions is similar. Moreover, X-ray diffraction, optical and scanning electron microscope observations show that although the ferromagnesian minerals are preferentially associated with an embryonic form of the clay mineral halloysite, they are still relatively fresh. We interpret our results as indicating that in this instance microbial activity, and particularly fungal activity, has not been an effective agent of mineral weathering, that the association with clay minerals is indirect, and that fungal weathering of primary minerals may not be as important a source of plant nutrients as previously claimed.

Commercial forestry plantations as a postmining land use in the Upper Hunter Valley of New South Wales, Australia are restricted by both the poor nutrient availability of mining substrates and low regional rainfall. An experiment was conducted to investigate whether municipal waste products and saline groundwater from coal mining operations could improve early tree growth without impacting on the environment through salt accumulation and/or nutrient enrichment and changes in groundwater quality. Potential impacts were investigated by quantifying the nutrient cycling dynamics within the plantation using an input-output mass balance approach for exchangeable calcium (Ca(2+)), exchangeable magnesium (Mg(2+)), exchangeable potassium (K(+)), exchangeable sodium (Na(+)), nitrogen (N), and phosphorus (P). Measured inputs to and outputs from the available nutrient pool in the 0-30 cm of the overburden subsystem were used to estimate the net effect of unmeasured inputs and outputs (termed "residuals"). Residual values in the mass balance of the irrigated treatments demonstrated large leaching losses of exchangeable Ca, Mg, K, and Na. Between 96% and 103% of Na applied in saline mine-water irrigation was leached below the 0-30-cm soil profile zone. The fate of these salts beyond 30 cm is unknown, but results suggest that irrigation with saline mine water had minimal impact on the substrate to 30 cm over the first 2 years since plantation establishment. Accumulations of N and P were detected for the substrate amendments, suggesting that organic amendments (particularly compost) retained the applied nutrients with very little associated losses, particularly through leaching.

The present study was designed to characterize dentin formed in transplanted rat molars by investigating calcium (Ca), phosphorus (P), and magnesium (Mg) concentrations using electron probe microanalysis (EPMA) as well as examining the rate of dentin matrix formation by vital staining. The unerupted immature lower right second molar in 2-week-old rats was transplanted into the upper right first molar socket. Rats were injected with oxytetracycline, calcein, and alizarin intraperitoneally at 1 day before and 1 and 2 weeks after transplantation, respectively, for vital staining. The maxillae and mandibles were fixed 3 weeks after transplantation, resected, and embedded in resin. Undemineralized sections were cut and examined by fluorescent microscopy and EPMA. The thickness of dentin formed in the first week after transplantation was significantly less than that of dentin formed in any other 1-week period in the transplanted tooth and was about one-fifth the thickness of dentin formed in control teeth. Formation of dentin recovered in the third week after transplantation. In the first week after transplantation, EPMA demonstrated a sharp increase in Mg concentration with a slight decrease in Ca concentration. Thereafter, no significant difference was identified among Ca, P, or Mg concentrations or the Ca/P ratio between transplanted and control teeth. These results suggest that disruption of the circulation and innervation by transplantation cause a temporary change in the matrix formation rate and elemental distribution of dentin, which is subsequently restored within 2 weeks after transplantation.

A case-control study was undertaken to understand the etiopathology of the bone deformities among young children in a fluoride-affected village of the Bihar State. Two villages were selected: one village with high fluoride in drinking water (7.9 +/- 4.15 ppm), and the other village with normal levels of fluoride (0.6 +/- 0.31 ppm) as the control village. The source of drinking water was bore wells in both the villages. Two hundred and forty subjects from 54 households (HHs) of the high-fluoride village (HFV) and 1443 subjects from 197 HHs of the control village were selected for the study. Dental mottling (DM) was observed in 50% and skeletal deformities of various forms were observed in 20% of the total population of HFV, whereas, in the control village, DM was 6% and skeletal deformities were absent. The prevalence of both, DM and skeletal deformities was high in the younger age group of 1.5 to 14 years. Genu valgum, genu varum, bowing of tibia, saber shin, and widening of the lower ends of long bones at the wrist were the typical skeletal deformities observed among affected children in the HFV. X-rays of the children with deformities revealed varying degrees of bending of bones and enlargement of epiphyseal ends of metaphyses with fraying of bone and ligamental calcification. A survey indicated significantly low calcium and high phosphorus intake among the population of the HFV as compared to that of the control village, possibly resulting from low intake of milk and high intake of potatoes, respectively. The mean urinary fluoride level was significantly higher in the children of the HPV, both with and without deformities, as compared to that of the control village. The mean serum 25 OHD3 (25 Hydroxy Vitamin D) and calcium levels were significantly lower and alkaline phosphatase activity was significantly higher among the children with deformities as compared to those without deformities from the HFV and the control village. Serum intact parathyroid hormone (IPTH) levels were high in children both with and without deformities in the HFV as compared to those in the control village. No significant differences were observed in the concentration of serum and urinary creatinine, and Cu, and Mg levels between the HFV and the control village. It can be concluded that some of the children from the HFV manifested severe bone deformities (rickets), which were confirmed by the existence of low serum calcium and vitamin D levels.

Objective: To evaluate the effect of changing the amount of pre-dilution replacement fluid on the sieving coefficient (SC) and mass transfer of small solutes during isovolaemic high-volume haemofiltration (HVHF)., Design and Setting: Prospective interventional study in the intensive care unit of a tertiary university hospital., Patients: Eight patients with septic shock., Interventions: Isovolaemic HVHF (6 l/h of replacement fluid) was performed. The proportion of replacement fluid delivered in pre-filter was altered to progressively decrease it from 6 to 0 l/h. Samples were simultaneously taken from the "pre-filter", "post-filter" and ultrafiltrate (UF) sampling ports., Measurements and Results: Sodium, potassium, chloride, total calcium, total magnesium, phosphate, total CO(2), urea, creatinine and glucose concentrations were measured in each sample. The sieving coefficients of chloride, total CO(2), phosphate, urea and glucose were higher than 1 in most pre-dilution states. The sieving coefficients of sodium, potassium, calcium, magnesium, total CO(2) and urea decreased significantly with decreasing pre-dilution fluid rate. The sieving coefficients of chloride and glucose increased with decreasing pre-dilution fluid rate. There was a significant mass gain of sodium and glucose under all pre-dilution conditions. Mass chloride gains decreased with decreasing pre-dilution rates and changed into chloride loss during 6 l/h of post-dilution. Decreasing pre-dilution improved urea and creatinine mass removal., Conclusions: Small solute SC and mass transfer during isovolaemic HVHF are significantly affected by the proportion of replacement fluid administered pre-filter. Isovolaemic HVHF is neither isonatraemic nor isochloraemic.

Bisphosphonates have been widely used in the treatment of human bone pathologies including osteoporosis. In this case, bisphosphonates have been shown to reduce bone resorption, thereby increasing the mass and mechanical resistance of bone. Determining the effects of these molecules on the properties of the bone apatite crystals could provide a better insight into the mechanism of bisphosphonate/bone interaction. The aim of this study was to determine the ultrastructural effects of a third generation bisphosphonate (tiludronate) on the morphology, size, distribution, chemical composition, and structure of apatite crystals in bone (trabecular) in a rat osteoporotic model. Four groups of rats were studied: (1) sham operated, (2) untreated ovariectomized (OVX), (3) OVX rats which received 35 mg/kg of tiludronate, (4) OVX rats which received 160 mg/kg of tiludronate. The rats of groups 3 and 4 received tiludronate orally in 2 consecutive days every week for 1 year. Scanning electron microscopy (SEM), high and low resolution transmission electron microscopy (TEM), and electron microprobe analysis (EDX) were used for the ultrastructural characterization of the bone mineral. This study demonstrated that tiludronate slightly increased the width of bone apatite crystals without changing any other crystal characteristics.

Magnesium is an important intracellular cation which is known to participate in over 300 biochemical reactions of the cell. Most of the cell's Mg2+ is bound to intracellular structures, and only 5% of the total Mg2+ are unbound and thus biologically active. Clinical data concerning the therapeutic value of Mg2+ in various conditions like myocardial infarction are conflicting, experimental support for a specific therapy is still lacking, because values of free intracellular myocardial Mg2+ as well as behaviour of (Mg2+)i during ischemia or changes of extracellular ion-concentrations have not been elucidated as yet. Various techniques like Mg2+ sensitive dyes, nuclear magnetic resonance spectroscopy or Mg2+ selective microelectrodes have been employed, each of these techniques, however, harbours serious limitations.

This study determines ash, K, Ca, Na, Mg, Fe, Cu, Pb, and Zn content in musts and wines of the DOC Tacoronte-Acentejo (Tenerife, Canary Islands) from two consecutive harvests. Samples were treated with HNO3 and H2O2. Na and K were determined by flame photometry and the remaining metals by air/acetilene flame atomic absorption spectrophotometry. Significant differences were observed in Na, Ca and Mg contents between both harvests, possibly due to climate conditions.

We report a detailed analysis of the content of aluminum, iron, zinc, copper, calcium, and magnesium in the non-vascular and pericapillary mineralizations and the normal capillaries of the globus pallidus and dentate nucleus of the cerebellum in two patients with clinically and neuropathologically confirmed Fahr's disease. The study employed laser microprobe mass analysis, a technique that enables highly sensitive detection of the levels of trace elements. In the globus pallidus, there was a significant increase in aluminum-, iron-, zinc-, and calcium-related peak intensity in the pericapillary and non-vascular mineralizations compared to the normal capillaries. The pericapillary and non-vascular mineralizations had comparable concentrations of these elements. No difference was found in copper levels between the different probe sites. Magnesium was almost absent in pericapillary mineralizations and normal capillaries, while it accumulated within non-vascular mineralizations. In the cerebellar dentate nucleus, non-vascular mineralizations displayed higher concentrations of all of these elements than normal capillaries, while pericapillary mineralizations had a higher aluminum and lower iron, copper, and calcium content than did non-vascular mineralizations. Zinc and magnesium were selectively deposited within the non-vascular mineralizations in this nucleus. Furthermore, the element composition of non-vascular mineralizations differed between the globus pallidus and dentate nucleus. These findings indicate that the formation of pericapillary and non-vascular mineralizations may be two independent phenomena which coexist in the course of Fahr's disease. The marked qualitative and quantitative differences in trace element content in non-vascular mineralizations between the globus pallidus and cerebellar dentate nucleus suggest that the involvement of trace elements in the pathogenesis of Fahr's disease is probably indirect.

Cerium, a lanthanide, is the most abundant rare earth element present in monazite and is biologically active. It has been postulated that cerium toxicity in conjunction with magnesium deficiency causes tropical endomyocardial fibrosis, a restrictive human cardiomyopathy (Valiathan et al. 1989; Valiathan and Kartha 1990). Generally, lanthanides are known to be poorly absorbed (Durbin et al. 1956; Evans 1990). The present study was carried out to ascertain whether magnesium deficiency promotes accumulation of cerium in various organs of rats.

The combined effects of caffeine and alcohol on mineral contents of fetal mandibles and femurs were studied. Pregnant rats were divided into four groups: group 1, control; group 2, caffeine; group 3, alcohol; and group 4, caffeine-plus-alcohol. Alcohol (1.0 g ethanol/kg body weight) was intubated twice daily, beginning at day 9 of gestation. Caffeine (2 mg/100 g body weight) was given as a dietary supplement. Groups 1 and 2 were intubated with isocaloric sucrose solution. At birth, randomly selected pups were killed and the mandible and femur were removed and dried. Ca, P, Mg, Zn and hydroxyproline in these bones were measured. Notwithstanding the dams' intake of caffeine and alcohol administered separately, the present results suggest that the combination of caffeine and alcohol exhibited the most detrimental effects.

The daily dietary calcium and magnesium intakes in Belgium were evaluated by sampling duplicate portions of food, destruction in a microwave oven and their calcium and magnesium contents determined by atomic absorption spectroscopy. The mean intake value for calcium (618 +/- 125 mg/day) was found to be less than those values measured in most other countries and was below the recommended daily allowance (RDA). The mean intake value for magnesium (271 +/- 44 mg/day) was similar to levels found in most other countries, but was below the RDA value for healthy adult men (350 mg/day) whilst being adequate for healthy women (280 mg/day).

To evaluate the accuracy of bone mineral composition determination by electron microprobe analysis (EDX) the measurements have been compared to instrumental neutron activation analysis (INAA) and chemical analysis (ICPES). Bone specimens from five femoral heads were used. The trabecular content of calcium (Ca) and phosphorus (P) was analyzed by the three different methods. The EDX method allows for a microstructural analysis of intact, methylmetacrylate-embedded, undecalcified bone and the measuring points can thus be distinctly identified centrally in each trabecula. The analysis yielded 25.8 +/- 0.7 wt % Ca and 10.5 +/- 0.1 wt % P, compared with 22.2 +/- 0.5 and 23.0 +/- 1.0 wt % Ca, and 9.83 +/- 0.21 and 10.02 +/- 0.44 wt % P for INAA and ICPES, respectively. The EDX analysis was calibrated by consecutive measurements of a hard, pressed tablet of hydroxyapatit of known content. The mean Ca content deviated with -0.38 wt % from the given content and P with -0.89 wt %. We could not verify any particular interference from the embedding procedure, however, it is possible that the relatively lower P content still may reflect this. The magnesium (Mg) concentration was 0.31 +/- 0.02 wt % by EDX and 0.26 +/- 0.02 wt % by INAA. The EDX analytical method provides a useful tool for simultaneous elemental quantification in bone. It has the advantage of permitting the use of regular bone biopsy material and thus allowing for a unique microstructural evaluation of the degree of mineralization.(ABSTRACT TRUNCATED AT 250 WORDS)

Elevated erythrocyte cytosolic free calcium, and suppressed free magnesium and pH values are associated with the hyperinsulinaemia and insulin resistance of hypertension, obesity, and Type 2 (non-insulin-dependent) diabetes mellitus. To determine the role of insulin in this process, we utilized 19F- and 31P-nuclear magnetic resonance spectroscopy to study the cellular ionic effects of insulin in vitro on normal human erythrocytes. Insulin elevated cytosolic free calcium levels in a dose- and time-dependent manner. The effect began at 10 microU/ml, peaked at 200 microU/ml, and continued at both the 500 microU/ml and 1000 microU/ml doses. At 200 microU/ml, free calcium levels rose from 24.6 +/- 2.5 nmol/l to a peak value at 120 min of 66.4 +/- 11 nmol/l (p < 0.05 vs basal), levels remaining elevated throughout the incubation (45.7 +/- 5.6 nmol/l at 60 min, and 47.9 +/- 9.1 nmol/l at 180 min, p < 0.05 vs basal, respectively). Similarly, insulin also increased intracellular free magnesium at all time points (basal: 177 +/- 11 mumol/l; 60 min: 209 +/- 19 mumol/l; 120 min: 206 +/- 22 mumol/l; and 180 min: 202 +/- 12 mumol/l; p < 0.05 vs basal at all times). No insulin-induced changes in pH were observed. We conclude: (i) that insulin in physiological concentrations may participate in regulating divalent cations in the mature human erythrocyte, (ii) that insulin per se cannot account for the previously described cellular ionic lesions of hypertension and diabetes, and (iii) that future clinical studies of cell ion metabolism should be conducted in the fasting state, be controlled for ambient circulating insulin levels, or both.

The macroelement (sodium, potassium, calcium and magnesium) concentrations have been determined in various tissues of the Common Pacific squid, Loligo opalescens. The method of measurement was flame atomic emission (sodium and potassium) and absorption (calcium and magnesium) spectrometry. Edible tissues such as the tube (mantle), arms and crown, and fin contained: from 3.3 +/- 0.4 to 3.9 +/- 1.5 (1.9-6.8) g/kg wet weight of sodium; from 5.3 +/- 0.6 to 6.3 +/- 2.7 (3.3-14) g/kg of potassium; 38 +/- 7 to 100 +/- 34 (28-200) mg/kg of calcium; and from 510 +/- 100 to 950 +/- 280 (340-1500) mg/kg of magnesium. The other tissues or organs examined frequently contained a higher concentration of macroelements than the edible flesh. Statistically significant correlations between the body weight of squid and macroelement concentrations or between some pairs of metals in whole squid, mantle and hepatopancreas have been observed.

This study examined the effects of chronic protein deficiency and fluoride administration (10 mg/kg/day), separately or in combination, on rat tibia properties. Protein deficiency increased the bone fluoride concentration and reduced the bone mineral content (BMC) especially at the proximal or growing end which contains mainly cancellous bone. Fluoride administration also reduced BMC, but to a lesser extent, and it resulted in proximal tibia fluoride concentrations that were nearly twice those of the distal tibia. The interaction between fluoride administration and the protein content of the diet on BMC was nonsignificant, suggesting that the effects were additive, not multiplicative or synergistic. Fluoride administration, but not protein deficiency, increased bone magnesium levels. It is hypothesized that the reduction in BMC in the areas where the fluoride concentrations were the highest was due to a localized toxic effect of fluoride.

To determine whether subchondral bone in osteoarthritis differs from that seen in normal human aging, osteoarthritic femoral heads removed for total hip arthroplasty were compared with normal age-matched and young autopsy controls. Standardized, 1-cm deep, weight-bearing and nonweight-bearing subchondral bone blocks, as well as cancellous core bone, 2-4 cm deep on the articular surface, were examined in each femoral head. Mineralization was assessed using density fractionation and chemical analysis, and compared to histomorphometry. In osteoarthritis, both weight-bearing and nonweight-bearing surface subchondral bone showed a lower degree of mineralization than age-matched and young controls. Histomorphometric analysis showed that subchondral bone thickness, as well as all osteoid parameters and eroded surfaces, were increased in osteoarthritic samples versus controls. Mineralization in the deep cancellous core bone increased with normal aging but underwent less change with osteoarthritis. Histomorphometry of the cancellous core showed that osteoid parameters, but not bone volume, were increased in osteoarthritis versus controls. In conclusion, osteoarthritis is associated with a thickening of the subchondral bone with an abnormally low mineralization pattern.

A flame atomic absorption spectroscopic (FAAS) method is described for the determination of calcium and magnesium in a wide variety of foods and biological substrates. Results for reference materials (n = 9) are presented that demonstrate the validity of the procedure. Samples are digested with nitric acid at 150 degrees C in a pressure decomposition vessel, diluted and adjusted to pH 2 with ammonia. Lanthanum chloride solution is added to suppress phosphate interferences and the ionization of calcium and magnesium in the AAS flame. Additional dilutions are made as appropriate, whereupon the atomic absorption of calcium and magnesium is measured in an oxidizing air-acetylene flame. The wavelength settings for calcium is 422.7 nm and for magnesium 285.2 nm. The method was tested in a collaborative trial involving a milk powder practice sample and four test samples, all of which were reference materials. Participants were requested to carry out duplicate determinations exclusively. Results were obtained from 12 laboratories. However, the results of 3 laboratories had to be rejected for various reasons. The remaining set of data was statistically evaluated according to ISO 5725; the method of analysis proved to be precise and accurate. Coefficients of variation values for calcium ranged from 1.19% to 4.44% within laboratories (CVr) and from 5.30% to 15.9% between laboratories (CVR). For magnesium, the corresponding values were CVr, 1.07% to 3.52% and CVR, 3.07% to 5.99%. The method is recommended for the determination of calcium and magnesium at the levels considered in foods and biological substrates.

For the simultaneous analysis of the cations Li, Na, K, Ca, and Mg as well as Mn and the anions hydrogen carbonate, chloride, sulfate and nitrate, silica gel- and polymer-based ion exchange materials with conductivity and spectrophotometric detection combined with a post-column derivatization system (PAR-Zn-EDTA for Ca, Mg, Mn) and also an ion-pair system with RP-18 phase were compared with a view to their application to mineral water samples. It is possible to determine Li, Na, and K in such samples with or without the suppressor technique using polymer columns. A polybutadiene maleic acid silica gel cation exchanger material makes feasible simultaneous analysis of alkaline and earth alkaline metals. Ca, Mg, and hydrogen carbonate, chloride, sulfate and nitrate are analyzed in less than 16 min using a silica gel anion exchanger with EDTA as the eluent. To stay within the linear range of the calibration function it is necessary to perform two injections in different dilutions (between 1:4 and 1:500) due to the different concentration ratios. For the analysis of manganese above 100 micrograms/L a system with the cation exchanger Partisil SCX and the eluent ethylenediamine/oxalate with post-column derivatization is used. The sample pretreatment is done by reduction with thiosulfate. A total of 15 different mineral waters were analyzed with all the systems and the results were compared with those of reference methods (AAS, potentiometry), showing good conformity.

Calcium-deficient carbonate apatites in urinary calculi from 17 patients have been studied. Magnesium ions in each case were detected as a component of apatite. In most of the cases, CO23- ions were included in the apatitic lattice. Using a calcination procedure, we have determined the most probable average value for the CO23- content, degree of deficiency, x, and the Mg/Ca ratio in each sample.

A solid-state chemical model is derived to estimate the solubility of dolomites having different degrees of cation ordering. It is shown that the solubility of dolomites formed by precipitation at ordinary temperatures is such that it allows for the formation of dolomite in tooth enamel during in vivo mineralization.

The calcium phosphate remaining after hydrazine deproteination of casein micelles isolated from bulk skim milk exhibits under the electron microscope a very fine and uniform granularity being formed by small subunits with a true diameter of approximately 2.5 nm. This material, which is about 10 percent by weight citrate, termed calcium phosphate citrate (CPC) complex, also contains Mg and Zn at molar ratios of 0.03 and 0.003 respectively. Radial distribution function (RDF) and infrared analyses show that CPC is a Mg-containing amorphous calcium phosphate (ACP) similar to synthetic and cytoplasmic ACP. presence of CPC in casein micelles as an amorphous colloid bonded with phosphoproteins provides the means for storing in milk large amounts of Ca (16 mM) and Pi (10 mM) in a readily utilizable form but at a higher ion concentration than found in biological solutions.

From fracture callus in different stages of mineralization the contents of Mg, CO2, Ca and P were determined and compared with those found in predentine. It was found that the Mg- and CO2-contents are high in relation to Ca and P values during the prestages and early stages of mineralization. These relatively high Mg- and CO2-values are connected with high Mg/Ca, Mg/P, CO2/Ca and CO2/P ratios which strongly decrease with the increasing degree of mineralization. These results seem to be part of a general controlling mechanism of the calcification.

The presence of lipids in urinary stones was determined by histochemical and biochemical methods. When crystals of calcium oxalate, made by mixing calcium chloride and potassium oxalate solutions and sections of human calcium oxalate urinary stones, were exposed to osmium vapors, there was no staining of the pure crystals whereas the stone sections were stained. De-paraffinized sections of demineralized calcium oxalate stones showed positive sudanophilia on staining with Sudan black B. Both these experiments indicate the presence of lipids in calcium oxalate stones. Lipids were extracted from uric acid, struvite, and calcium oxalate stones using standard techniques. Phospholipids were separated by one-dimensional thin layer chromatography. All the stones studied contained lipids. In calcium oxalate stones they accounted for 10.15% of the matrix. Calcium oxalate and struvite stones contained more phospholipids than uric acid stones. Cardiolipin, sphingomyelin, phosphatidyl choline, phosphatidyl inositol, phosphatidyl ethanolamine, phosphatidyl serine, and phosphatidyl glycerol were identified in lipid extracts. Demineralization by ethylenediaminetetra-acetate (EDTA) treatment increased lipid output from calcium oxalate stones by 15.5%.

The literature on how Mg is present in tooth enamel and on the incorporation of Mg in synthetic apatites is reviewed. Then a theoretical consideration is given on the basis of ionic radii about the incorporation of Mg in F-, Cl- and OH-apatite. Finally, the results are given of experiments on the incorporation of Mg in fluor, chlor, hydroxy, and carbonate apatite. It appears that the extent of incorporation of Mg in the apatite lattice, if at all, is very limited and that Mg in tooth enamel is to a very limited extent incorporated in the apatite lattice, the main portion being surface bound or present in a separate phase.

Urolithiasis is seen in our region throughout the year as a periodic appearing disease with peaks not only in summer, but also--somewhat lower--in January, April and October. This appearance is especially caused by the calcium oxalate stones. Uric acid calculi show a rise between May and October. The magnesium ammonium phosphate stones appear almost completely irregular.

The effect of magnesium deficiency on bone cell differentiation and bone formation was investigated using in vivo matrix-induced endochondral ossification as a test system. Demineralized bone matrix was implanted subcutaneously in young (35-day-old) male Long-Evans rats that had been fed a semisynthetic Mg-deficient diet (50 ppm Mg) for 7 days. Plasma Mg levels were reduced to 25-30% of control values at that time. Control rats were paired the same diet, supplemented to contain 1000 ppm Mg. The implants were harvested 7, 9, 11, 15, and 20 days after implantation and analyzed for Mg and Ca content, 45Ca incorporation, and alkaline phosphatase levels. At each stage, plaques (implants) removed from Mg-deficient rats showed retardation in cartilage and bone differentiation and matrix calcification. Magnesium content was markedly reduced when compared to the control plaques. Histological appearance of the matrix-induced plaques confirmed the retardation in bone development and mineralization suggested by the chemical indicators. Most marked was the virtual absence of bone marrow in 20-day-old plaques in Mg-depleted rats. These data show that bone cell differentiation can occur in a severely Mg-depleted environment, although the onset of mineralization and bone remodeling was delayed and bone marrow differentiation was impaired.

Aortas with isthmus stenosis (coarctation) can be regarded as a model for those changes of the vessel wall, that depend on blood pressure, as one can compare the proximal region (high pressure) with the distal one (low pressure). The Na, Mg, P, S, Cl, K, and Ca content of the vessel walls of 5 patients (age: 2 months to 34 years) were determined by electron probe microanalysis. We have used cryostat sections and measured the element concentrations from the lumen to the outer media. In this paper we discuss especially the measurements of Ca and P, as the mineral being deposited in the vessel wall, e.g. in arteriosclerosis, contains Ca and P. Up to 18 years Ca and P enrichments are found only in a subintimal band parallel to the lumen. The proximal region of the aorta of a 34 years old patient, however, demonstrated Ca and P enrichments in the whole media with a high peak in the subintimal band. The enrichments are proximally always higher than distally. Only in the distal region of the 2 months old infant no Ca or P enrichments were found, but they appeared proximally. Thus high blood pressure causes an enrichment of Ca and P in a subintimal band very rapidly and promotes the mineralization of the vessel wall. The quantitative electron probe microanalysis demonstrated these pathological alterations.

Bone specimens from the anterior iliac crest were collected post-mortem from 128 subjects whose death had been primarily caused by acute coronary disease or accidents. The cortical bone was separated and used for the following determinations: citrate by an enzymatic method, carbon dioxide by microdiffusion, chloride and phosphorus by spectrophotometry, fluoride by the ion-selective electrode technique, and Ca, Mg, Zn by atomic absorption spectrophotometry. The citrate concentration (+/- SD) was 10.9 +/- 3.1 mg/g (dry weight) and was not age-dependent. A statistically significant negative correlation was obtained between citrate and carbon dioxide, however, which was confirmed by regression analysis. The only statistically significant differences in carbon dioxide and fluoride concentrations between three citrate groups were obtained between the lowest group (3.2-8.7 mg/g) and the highest (13.1-16.8 mg/g). In conclusion an inverse relationship may suggest either an effect of citrate on the binding of carbonate to apatite structures, or that the carbonate concentration is dependent to a slight degree on citrate metabolism.

The free Mg++ concentration in endolymph was measured with Mg++-selective microelectrodes based on the neutral ligand ETH 1117. The property of Mg++ microelectrodes was obtained from calibration solutions, containing various Mg++ concentrations with the background electrolytes resembling endolymph. The range between 10 and 0.1 mM Mg++ concentrations changed the potentials of Mg++ microelectrodes by 14.4 +/- 3.0 mV. The endocochlear potential and the Mg++ concentration in the endolymph were 82.0 +/- 5.0 mV and 0.77 +/- 0.29 mM in the guinea pig, and 84.4 +/- 4.9 mV and 1.12 +/- 0.24 mM in the chinchilla, respectively. These results are discussed in the light of the dependence of Na+, K+-ATPase and its interaction with Ca++.

The viscosity of gastric juice and the concentrations of sodium, potassium, calcium, magnesium and chloride ions were measured before and after stimulation with pentagastrin in 10 children with cystic fibrosis and compared to those in 10 healthy children of corresponding ages. The viscosity values followed the same patterns as those for the sodium and calcium ion concentrations and were higher in the cystic fibrosis group. The electrolyte concentrations in the basal and different post-stimulation fractions of the gastric juice were higher in the cystic fibrosis group. Significant differences between both groups could only be found in the electrolyte concentrations. The total secretion of each of the electrolytes was the same in both groups because along with the increased electrolyte concentration in the cystic fibrosis group there was a reduced volume of gastric juice. The dependence of viscosity on the individual electrolyte concentration is discussed. The differences in the viscosity and the electrolyte concentrations in gastric juice from the cystic fibrosis children seems to be due to changes in the process of gastric secretion and not due to the influence of swallowed saliva.

The content of calcium, magnesium, potassium and sodium in the walls of v.femoralis, v.saphena and v.brachialis was measured with atomic-absorption spectrometry. Calcium showed distinct differences among the veins with increasing age. There is a remarkably high increase and more inhomogenous distribution for calcium in the v.femoralis of older people.

The concentrations of magnesium and total calcium human vitreous humors obtained postmortem was tested. In the groups of heart disease and asphyxia a correlation between the postmortem interval and calcium or magnesium concentrations was found. There was no correlation between postmortem interval and calcium respectively magnesium in the other causes of death. It seems possible that the analysis of vitreous humor may be useful in both diagnosis and determination of postmortem interval in the cases of heart death and asphyxia.

The content of Cr, Mn, Cu, Mg, Ca, Zn, and Fe has been determined by atomic absorption spectrometry in 30 meningiomas and in Pacchionian granulations. The elements Cr, Mn, and Cu show no distinct relation to different tumor types. The broad spectrum of data for Fe is considered to be due to a different blood volume or microbleedings in the meningiomas clinically irrelevant in nature. The Ca-values correspond with the microscopic calcifications. An obvious coincidence exists partly between the high Ca- and Mg-values, in some tumors concentrations of Mg are partly higher than the concentrations of Ca. The latter finding is in concordance with tumors without microscopic calcifications. It is assumed that the inhibitory potency of Mg against mineralization reflects the metabolic antagonism between Ca and Mg. The highest values for Zn are seen in fibromatous meningiomas. This finding possibly corresponds with the function of Zn as co-enzyme in the synthesis of proteins in this copiously reticulin- and collagen-producing type of meningioma.

Normal rat bone maturation has been studied using biochemical methods and hydrazine separation of matrix and mineral for X-ray diffraction. In the bone, the amount of mineral increases between 4 and 22 weeks of age, while in the matrix, the ratio of noncollagenous protein to collagen progressively decreases. In mineral, in the absence of serum ion changes, growth in mean crystal size appears to be the determinant of the changing ratios of calcium, magnesium, carbonate, and phosphorus, and of the increasing mineral density.

A time course of tissue ionic changes, and their relation to ultrastructural findings during reperfusion following a 15-min global ischemic brain insult was studied in a dog model. Parietal cortex was analyzed for Ca, Na, K, Mg and Fe in controls and after 10 min, 2, 4, and 8 h of reperfusion. After 8 h of reperfusion, the mean values (mumol/g tissue wet wt.) for Ca (control = 1.43, 8 h = 2.76) and Na (control 60.4, 8 h = 107.4) doubled and K (control = 90.4, 8 h = 48.5) decreased to half that of the control. Ultrastructural studies and subcellular localization of calcium in parietal cortex of in situ-fixed brains after 8 h showed cortical neurons with clumping of nuclear chromatin, dilatation of endoplasmic reticulum and disruption of plasma membranes. Large amounts of electron-dense precipitates of calcium were present within dilated astrocytic processes, synaptic vesicles, cytoplasm of edematous dendrites and mitochondria. Cortical neurons from postischemic dogs without reperfusion showed only slight chromatin clumping and edema of astrocytic processes, but no calcium accumulation. The large ionic shifts noted between 4 and 8 h of reperfusion, indicate a progressive inability of the cells to maintain normal transmembrane gradients of these ions and may reflect a membrane destructive process, as demonstrated ultrastructurally at 8 h. Enhanced calcium entry into the neuron during reperfusion appears to be a part of the cytotoxic mechanism leading to neuronal necrosis.

Apatites containing Na, Mg, and CO3 in amounts occurring in tooth enamel mineral were synthesized by precipitation from aqueous solutions. The X-ray diffraction patterns showed only apatitic reflections, which were somewhat broader than those of enamel. X-ray Guinier photographs resulted in diffuse reflections from which the lattice parameters could not be determined. The infrared (IR) absorption spectrum of the synthetic samples was practically identical with that of tooth enamel. However, after heating the samples for 1/2 h at a temperature between 300 and 600 degrees C, no absorption peak was found at 2340 cm-1 as in the IR spectrum of tooth enamel after heating.

SPD calcifications from four cases of Fahr's disease were studied with an electron microprobe of Castaing, and found to contain different elements, among them Zn, Al, Mg. The presence of the elements is underlined not because of presumption as to their importance on the pathogenesis of this disease, but because of their rare identification in cerebral calcifications. A1 and Mg have been localized previously in cerebral calcification, but this is the first report of morphological localization of a high concentration of zinc in the brain. Two of these cases had hypoparathyroidism.

Determination of sodium, potassium, calcium, magnesium, iron, copper, zinc, and manganese in organic material is possible with one digestion using the described extraction method. Data for sodium, potassium, calcium, magnesium, iron, and manganese agree well with those obtained by conventional methods [1, 2, 4]. For quantitative determination of copper and zink the extraction method is superior to dry ashing at 450 degrees C [1, 4]. In general the extraction method ist preferable to dry assing, because the amount of sample, time and costs can be reduced essentially using the described method.

We have studied saccular and utricular otoconia from Shaker-1 and Shaker-2 mice by X-ray diffraction and scanning electron microscopy. In contrast to previous reports, we found that the crystals were composed of calcite rather than polycrystalline hydroxylapatite. These crystals were indistinguishable mineralogically and morphologically from normal mouse otoconia. The reported occurrence of hydroxylapatite otoconia in the Shaker mouse is probably false.