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The aim was to evaluate the influence of dietary Ca-Mg-phytate consumption on the bone characteristics of ovariectomized rats, an animal model for postmenopausal osteoporosis. Twenty ovariectomized female Wistar rats were randomly assigned to two groups fed, respectively, with a non-phytate diet (AIN-76A) or the same diet enriched with 1% phytate (as the calcium magnesium salt, phytin). After 12 weeks of feeding the rats were sacrificed, and both femoral bones and L4 vertebra were removed from each rat. Bone mass, length, width, volume, and mineral density were measured, and the phosphorus, calcium, magnesium, and zinc contents of bones were determined. Deoxypyridinoline (a bone resorption marker) was measured in urine, and osteocalcin (a bone formation marker) was measured in serum. The calcium and phosphorus contents and bone mineral density were significantly higher in both femoral bones and L4 vertebra for phytate-treated rats in comparison to rats in the non-phytate group. Deoxypyridinoline was significantly increased in rats in the non-phytate treatment group. Ca-Mg-phytate consumption reduces bone mineral density loss due to estrogen deficiency. Thus, phytate exhibits effects similar to those of bisphosphonates on bone resorption and may be of use in the primary prevention of osteoporosis if larger studies in humans confirm these findings.

Background: Important health benefits have been reported recently to phytate intake. This includes the prevention of pathological calcifications such as renal calculi, dental calculi and cardiovascular calcification, due its action as crystallization inhibitor of calcium salts, and as preventive of cancer., Aim of Study: The aim of this study was to establish a relation between the intake of phytate, through consumption of typical components of the Mediterranean diet (including nuts), and its excretion in urine., Methods: This study recruited participants from subjects included in a larger trial (PREDIMED) of food habits, that were assigned to one of two diet groups: (1) the Mediterranean diet with low proportion of phytate-rich food group, where participants were asked to maintain their usual diet; and (2) the Mediterranean diet with high proportion of phytate-rich food group, where participants were asked to increase phytate-rich foods in their diet. Phytate intake was assessed on the basis of a food frequency questionnaire. Urinary phytate excretion was determined in 2-h urine samples., Results: The overall phytate consumption of the Mediterranean diet with high proportion of phytate-rich food group (672 +/- 50 mg) was significantly higher than the Mediterranean diet with low proportion of phytate-rich food group (422 +/- 34 mg), representing a 59% difference. Urinary phytate excretion was also significantly higher (54%) in the Mediterranean diet with high proportion of phytate-rich food group (1,016 +/- 70 microg/L) than the Mediterranean diet with low proportion of phytate-rich food group (659 +/- 45 microg/L)., Conclusions: Mediterranean diets high in whole cereals, legumes and nuts compared to Mediterranean diets low in these phytate-rich foods increase the urinary phytate excretion in humans.

This study evaluated the relationship between phytate urinary levels and bone characteristics in a large population of postmenopausal women. The study population consisted of 180 postmenopausal women who participated in a descriptive cross-sectional study. A urine sample was collected from each subject to determine phytate levels and the volunteers were divided into two groups according to phytate urinary concentration (i.e., low and high levels). Bone mineral density was determined in the lumbar spine and femoral neck of groups with low and high phytate urinary levels. Urinary levels of phytate were linked to dietary phytate consumption. Hence, bone mineral density values were significantly higher in the lumbar spines and femoral necks of women who consumed high levels of phytate than in women with low urinary phytate concentrations. Higher urinary levels of phytate correlated with higher bone mineral density in the lumbar spine and femoral necks of postmenopausal women. This finding demonstrates the potential use of phytate in the treatment of bone related diseases, as it uses a mechanism of action similar to some bisphosphonates.

Most studies on epidemiology, composition, and recurrence of renal calculi include both spontaneously passed calculi and those retrieved after surgical manipulation or shock wave lithotripsy. The present study exclusively focused on epidemiology, composition, and recurrence of spontaneously expelled stones in patients from North and East Mallorca (Spain) which represents a geographically specific non-urban region of a developed country. The study involved 136 patients who spontaneously passed 205 renal calculi. All calculi were classified and sub-classified according to composition after macroscopic and microscopic examination. We also analyzed prevalence, gender, age, and stone recurrence rate over a period of 3 years. The peak incidence of spontaneously stone passage is within the fourth to sixth decade. Overall male to female ratio was 3/1. Calcium oxalate was the most prevalent composition (64.8%) followed by uric acid (25.3%), mixed stones (5.3%) and calcium phosphate calculi (4.3%). Uric acid stones were the most recurrent (50%) followed by calcium oxalate monohydrate papillary calculi (26.4%), calcium oxalate monohydrate un-attached calculi (19.2%), calcium oxalate dihydrate calculi (18.3%), calcium phosphate calculi (14%), and mixed calculi (12.5%). In conclusion, spontaneously passed stones in Mallorcan population have similar epidemiology, composition, and recurrence rate from that found in other developed countries. Calcium oxalate stones are largely the most spontaneously passed type of calculi and uric acid stones are the most frequently recurred. These findings are also found to be similar to those reported in previous studies examining both spontaneously and non-spontaneously passed stones.

Melatonin is a hormone synthesized from the neurotransmitter serotonin and is found mainly in the pineal gland. Melatonin has been suggested to have several properties, acting both as an antioxidant and a neuroprotective agent. Melatonin synthesis decreases with age in all humans, but this decline is more pronounced in Alzheimer's patients. In fact, melatonin inhibits the formation of beta-amyloid protein. The mechanism responsible for this decline has not been fully elucidated, although it is known that the human pineal gland calcifies with age. Such calcification necessarily implies the existence of a tissue injury that, if not reabsorbed by the immune system, will act as heterogeneous nucleant for hydroxyapatite and will induce calcification. For this reason, it is hypothesized that a lack of inhibitors of calcium salt crystallization, such as pyrophosphate and phytate, will favor calcification. Therefore, the absence of crystallization inhibitors may be a risk factor for development of Alzheimer's disease, and this hypothesis should be evaluated.

Background and Objective: Dental calculus occurs as a consequence of supersaturation of saliva with respect to calcium phosphates. This mineralization of dental plaque can be delayed by the presence of crystallization inhibitors, such as pyrophosphate or bisphosphonates. Phytate inhibits brushite and hydroxyapatite crystallization and has the potential to prevent dental calculi formation. The aim of the present study was to examine the effects of phytate and zinc, administered in a mouthwash solution, to prevent the formation of dental calculus., Material and Methods: Healthy dental plaque-forming volunteers (n = 25) took part in a randomized, double-blind, three-period crossover clinical study to assess the efficacy of a phytate-containing mouthwash in relation to control and placebo effects. Subjects rinsed their mouths for 1 min, twice each day, with 20 mL of the test solution, without ingestion. Mouthwash efficacy was assessed through quantification of the amounts of calcium, phosphorus and magnesium present in the residues obtained by dental cleaning, performed by a single trained examiner., Results: A good correlation was found among total calcium, magnesium and phosphorus in calcified dental plaque residues, indicating that any of these variables is adequate for evaluating the reduction of plaque crystallization as calcium phosphate. A statistically significant decrease in total calcium, magnesium and phosphorus was found in the phytate-treatment period compared with control and placebo periods, demonstrating the efficacy of the proposed treatment in reducing dental calculus formation., Conclusion: The high efficacy of phytate in reducing dental calculus formation suggests that this substance may be an effective treatment for preventing the development of calculus deposits.

The article gives an overview of phytic acid in food and of its significance for human nutrition. It summarises phytate sources in foods and discusses problems of phytic acid/phytate contents of food tables. Data on phytic acid intake are evaluated and daily phytic acid intake depending on food habits is assessed. Degradation of phytate during gastro-intestinal passage is summarised, the mechanism of phytate interacting with minerals and trace elements in the gastro-intestinal chyme described and the pathway of inositol phosphate hydrolysis in the gut presented. The present knowledge of phytate absorption is summarised and discussed. Effects of phytate on mineral and trace element bioavailability are reported and phytate degradation during processing and storage is described. Beneficial activities of dietary phytate such as its effects on calcification and kidney stone formation and on lowering blood glucose and lipids are reported. The antioxidative property of phytic acid and its potentional anticancerogenic activities are briefly surveyed. Development of the analysis of phytic acid and other inositol phosphates is described, problems of inositol phosphate determination and detection discussed and the need for standardisation of phytic acid analysis in foods argued.

Objectives: Extracorporeal shock wave lithotripsy (ESWL) is one of the most commonly used procedures for removal of renal calculi from the upper urinary tract, but complete expulsion of the fragments generated is not always achieved. This can lead to new lithiasic episodes, and it is considered that 10-26% of fragmented calculi can undergo regrowth. This in vitro study investigated the influence of fragment and urinary composition on post-ESWL growth of fragments, with the aims of establishing the effect and importance of these parameters, and identifying effective prophylactic measures., Methods: Fragments collected from patients immediately following expulsion after ESWL treatment were selected for regrowth experiments. The particles included 24 calcium oxalate monohydrate (COM) fragments, 48 calcium oxalate dihydrate (COD), 24 hydroxyapatite (HAP), and 16 uric acid., Results: In all treatments, calculi fragments showed a considerable capacity to induce growth of calcium oxalate and calcium phosphate. Under normocalciuria conditions, new COM crystals formed; both COM and COD crystals developed under hypercalciuria conditions at a urinary pH < 6.0; and in hypercalciuric conditions and urinary pH > 6.0 both HAP and brushite (BRU) crystals were formed. The highest growth rates were observed for COD calculi fragments under hypercalciuria conditions and at a urinary pH of 6.5, followed by growth on COM and HAP fragments under the same conditions; growth rates under other conditions tested were similar but 10-fold lower. With regard to the role of crystallization inhibitors, phytate exhibited inhibitory effects under all assay conditions. However, citrate had little effect, even at the highest concentration tested (1,000 mg/L)., Conclusions: This study demonstrates the importance of avoiding heterogeneous nucleant retention (pre-existing solid microparticles) in renal cavities, as these can act as very efficient inducers of the formation of new calculi, the composition of which is mainly dependant on the urine composition.

We report a unique case of a melamine bladder urinary stone. A physiopathologic mechanism of formation is proposed and discussed.

Since ancient times, various herbal preparations have been used in renal lithiasis therapy, but conclusive scientific data on their therapeutic effects and efficacy are not available. To address this issue, the present study evaluated the antilithiasic activity of a traditional Mallorcan herbal preparation, and compared its effects with those of the antioxidant flavonoids, catechin and epicatechin. Thirty-six male Wistar rats were assigned randomly to four groups (n = 9): a control group, a catechin (CAT) treatment group, an epicatechin (EPI) treatment group, and a group treated with a folk herbal extract (FHE). After 16 days of treatment, calcium oxalate lithiasis was induced in the rats using ethylene glycol. After 8 days (treatment + ethylene glycol), 24-h rat urine was collected, the animals were sacrificed and their kidneys were removed for histological and chemical analysis. The calcium concentration in kidney tissue was significantly lower in the CAT-treated (2.4 +/- 0.3 mg/g), EPI-treated (1.8 +/- 0.3 mg/g) and FHE-treated (2.1 +/- 0.3 mg/g) groups, than in the control group (5.4 +/- 1.4 mg/g). Examination of paraffin-embedded kidney sections showed that control group rats had the greatest amount of calcification. There were no significant differences between control and treated groups with respect to urinary calcium, magnesium, oxalate and citrate concentrations. These results demonstrate the ability of herbal preparations and antioxidants to prevent the development of papillary and intratubular calcification in the kidney.

Several risk factors seem to play a role in the development of osteoporosis. Phytate is a naturally occurring compound that is ingested in significant amounts by those with diets rich in whole grains. The aim of this study was to evaluate phytate consumption as a risk factor in osteoporosis. In a first group of 1,473 volunteer subjects, bone mineral density was determined by means of dual radiological absorptiometry in the calcaneus. In a second group of 433 subjects (used for validation of results obtained for the first group), bone mineral density was determined in the lumbar column and the neck of the femur. Subjects were individually interviewed about selected osteoporosis risk factors. Dietary information related to phytate consumption was acquired by questionnaires conducted on two different occasions, the second between 2 and 3 months after performing the first one. One-way analysis of variance or Student's t test was used to determine statistical differences between groups. Bone mineral density increased with increasing phytate consumption. Multivariate linear regression analysis indicated that body weight and low phytate consumption were the risk factors with greatest influence on bone mineral density. Phytate consumption had a protective effect against osteoporosis, suggesting that low phytate consumption should be considered an osteoporosis risk factor.

Background: Understanding the mechanism of calcium deposition in soft tissues is of great importance in a variety of pathological conditions such as chronic kidney disease. The present study examined the role of phytate and osteopontin during the development of soft tissue calcification in an animal model., Methods: Male Wistar rats (16 rats per treatment) were fed with a diet (AIN-76A) in which phytate is undetectable (non-phytate-treated group), or with a phytin-enriched AIN-76A diet (phytate-treated group). After 21 days on the respective diets, all rats were subjected to calcinosis induction by subcutaneous injection with KMnO4 at 2 sites on either side of the interscapular region. At 2, 5, 8 and 10 days after the calcinosis induction, 4 rats of each group were sacrificed, and the injured tissues were removed for histological analysis and for calcium determination., Results: Calcification was notably and significantly reduced in phytate-treated rats compared with non-phytate-treated rats. Calcified deposits appeared as soon as 2 days after calcinosis induction, but inflammation with the presence of macrophages, lymphocytes and eosinophils was not typically observed until 5 days postinduction. Osteopontin was only detected 8 days postinduction, and was clearly associated with calcified areas., Conclusions: The results suggest an important role for crystallization inhibitors such as phytate in reducing hydroxyapatite crystal formation in the first steps of soft tissue calcification. Histological analysis indicated that osteopontin was not involved during initiation of soft tissue calcification. Osteopontin appears be involved in the control of calcification rather than its genesis.

Objective: The present study examined the inhibitory effects of pyrophosphate, etidronate, and phytate on bovine pericardium calcification in vitro., Methods: Bovine pericardium was glutaraldehyde fixed and then placed in a flow chamber in the presence of a synthetic physiological fluid alone (control) or the fluid plus various concentrations of pyrophosphate, etidronate, or phytate. Following a 96-h incubation, fragments were removed and assayed for calcification by measuring calcium and phosphorus levels., Results: The data indicated that both pyrophosphate and etidronate at 1 mg/l (5.75 and 4.95 microM, respectively) inhibited bovine pericardium calcification, whereas neither agent had an effect at 0.5 mg/l (2.87 and 2.47 microM, respectively). Phytate was the most potent inhibitor of calcification, and the effects of this agent were apparent at levels as low as 0.25 mg/l (0.39 microM)., Conclusions: While pyrophosphate, etidronate, and phytate were all able to inhibit bovine pericardium calcification in vitro, phytate was found to be the most effective.

The aim of this research was to evaluate the effect of dietary phytate on cardiovascular calcification in rats during aging. Male Wistar rats (10 weeks old) were randomly assigned to four diet groups. The control group was fed with a balanced diet (UAR-A04) containing phytate. The AIN group was fed a purified diet (AIN-76A) with an undetectable level of phytate. The PHY group was fed with a purified diet (AIN-76A) enriched with phytate (phytin, as the calcium magnesium salt). The MOD group was fed with the AIN-76A diet (phytate undetectable) enriched with MgO, inositol and CaHPO4. At 76 weeks of age all rats were sacrificed, and the aortas, hearts, kidneys, livers and femurs were removed for chemical analysis. The most significant differences were found in the aorta calcium content. Phytate-treated rats (the control and PHY groups) had significantly lower levels of calcium in the aorta compared to nonphytate-treated rats (AIN and MOD groups). The present study demonstrated that dietary phytate treatment significantly reduced age-related aorta calcification.

Background: The use of herbal medicines (medicinal plants or phytotherapy) has recently gained popularity in Europe and the United States. Nevertheless the exact mechanism of the preventive effects of these products is still far to be clearly established, being its knowledge necessary to successfully apply these therapies to avoid stone formation., Methods: The effect of oral lemon juice administration on calcium oxalate urolithiasis was studied in male Wistar rats. Rats were rendered nephrolithic by providing drinking water containing 0.75% ethylene glycol [v/v] (EG) and 2% ammonium chloride [w/v] (AC) for 10 days. In addition to EG/AC treatment, three groups of rats were also gavage-administered solutions containing 100%, 75% or 50% lemon juice [v/v] (6 microl solution/g body weight). Positive control rats were treated with EG/AC but not lemon juice. Negative control rats were provided with normal drinking water, and were administered normal water by gavage. Each group contained 6 rats. After 10 days, serum samples were collected for analysis, the left kidney was removed and assessed for calcium levels using flame spectroscopy, and the right kidney was sectioned for histopathological analysis using light microscopy., Results: Analysis showed that the rats treated with EG/AC alone had higher amounts of calcium in the kidneys compared to negative control rats. This EG/AC-induced increase in kidney calcium levels was inhibited by the administration of lemon juice. Histology showed that rats treated with EG/AC alone had large deposits of calcium oxalate crystals in all parts of the kidney, and that such deposits were not present in rats also treated with either 100% or 75% lemon juice., Conclusion: These data suggest that lemon juice has a protective activity against urolithiasis.

The aim of this paper is to study the variations in the percentage of the different types of renal stones with age and sex. Renal calculi were classified according to their composition and structure. Stone formers were divided according to age and sex, and the percentage of each kind of calculi in the different considered age periods for men and women were determined. It was found that calcium oxalate dihydrate calculi decreased with age, but only in men. These calculi were also clearly predominant in men. Hydroxyapatite calculi decreased with age in both men and women, but they were predominant in women. Uric acid calculi increased with age in both men and women, but were predominant in men. Finally, it was found that calcium oxalate monohydrate unattached calculi increased with age in both men and women. As a main novelty, the study here presented demonstrates the importance of distinguishing between calcium oxalate monohydrate papillary stones and calcium oxalate monohydrate unattached stones, since the etiologic factors responsible for their origin must be clearly different.

Background: Pathological calcification in soft tissues (ie, ectopic calcification) can have severe consequences. Hydroxyapatite is the common mineral phase present in all tissue calcifications. In general, the development of tissue calcifications requires a pre-existing injury as an inducer (heterogeneous nucleant), whereas further progression requires the presence of other promoter factors (such as hypercalcemia and/or hyperphosphatemia) and/or a deficiency in calcification repressor factors (crystallization inhibitors and cellular defense mechanisms). The present study investigated the capacity of etidronate (a bisphosphonate used in osteoporosis treatment) and phytate (a natural product) to inhibit vascular calcification in rats., Methods and Results: Six male Sprague-Dawley rats in each of the 3 treatment groups were subcutaneously injected with either a placebo (physiological serum solution), etidronate (0.825 micromol x kg(-1) x day (-1)) or phytate (0.825 micromol x kg (-1) x day(-1)) for 8 days. Four days into this regimen, calcinosis was induced by subcutaneous injections of 500,000 IU/kg vitamin D at 0 h, 24 h and 48 h. Ninety-six hours after the final vitamin D injection, the rats were killed and aortas and their hearts were removed for histological and calcium analyses. The data showed that phytate-treated rats had lower levels of aortic calcium than placebo-treated rats. All groups had similar heart calcium levels., Conclusions: The present study found that phytate acted as a vascular calcification inhibitor. Thus, the action of polyphosphates could be important in protecting against vascular calcification.

The aim of this study was to assess the inhibitory action of phytate in formation of renal calculi. Hypertension (induced by nicotine) combined with hypercalcemia (induced by D vitamin) was used to induce calcification in renal tissue in male Wistar rats that were fed a purified phytate free diet. Phytate non-treated rats developed significant calcium deposits in kidneys and papillae, as well as in kidney tubules and vessels, whereas calcium deposits were absent in control and phytate treated rats. Fragments of hydroxyapatite (HAP) calculi exhibited the capacity to induce the growth of calcium salts on their surfaces. Presence of 1.5 mg/L of phytate in the synthetic urine inhibited the formation of calcium oxalate monohydrate on HAP renal calculi in normocalciuric conditions. The findings show that the action of phytate as a crystallization inhibitor takes place both in the intrapapillary tissue and urine.

Ureterocele calculi are developed in cavities with urinary retention but far from the upper renal cavities. The structural features of three ureterocele calcium oxalate stones were observed by scanning electron microscope coupled with X ray microanalysis. The urinary parameters of the three patients were also determined. The stone A consisted of loose structure of large calcium oxalate dihydrate crystals and small spheres of hydroxyapatite. The interior contains disorganized plate-like calcium oxalate monohydrate crystals. The stone B was formed by a compact outer layer of calcium oxalate monohydrate columnar crystals. The structure of stone interior was similar to the stone A. The stone C was formed by concentric layers composed of either calcium oxalate monohydrate columnar crystals or hydroxyapatite. The core consisted of agglomerated calcium oxalate monohydrate crystals, hydroxyapatite and organic matter. From the urinary biochemical data it was deduced that two ureterocele patients (who formed A and B stones) were hypercalciuric (calcium > 300 mg/24 h), being 6.5 the urinary pH value of the patient that formed the A stone, and 7.0 the urinary pH of the patient that formed the C stone. The rest of urinary parameters for the three patients were normal. Thus, one of the requisite conditions for unattached stone development is the existence of a place inside the urinary tract where the solid particles that act as calculus initiator of the stone can be retained enough time to exert this action.

Objective: This paper deals with the mechanism by which uric acid affects calcium oxalate crystallization and the role of crystallization inhibitors in this process., Material and Methods: Pure uric acid crystals and fragments of uric acid renal calculi were used to induce calcium oxalate crystal formation and development. These studies were performed in flow systems, using synthetic urine and similar conditions to those found in real renal situations. The type and size of the developed crystals were evaluated by scanning electron microscopy and the amount of calcium oxalate crystallized was quantitated by means of inductively coupled plasma atomic emission spectroscopy., Results: The presence of uric acid crystals in a flow system provoked calcium oxalate monohydrate (COM) crystallization at a rate of 3.3 microg/h/mg uric acid. When uric acid renal calculi fragments were used, the amount of COM crystallized varied between 0.048 and 0.161 microg/h/mg of renal calculi depending on the porosity of the calculus. At particular concentrations (3.03 microM phytate, 28.75 microM pyrophosphate, 40 mg/l chondroitin sulphate) the crystallization inhibitors assayed produced a maximum decrease of approximately 50% in the amount of COM crystallized on uric acid crystals. Mucin (a glycoprotein) caused only slight effects., Conclusion: Uric acid crystals can clearly induce the development of COM crystals on them through a heterogeneous nucleation process and some crystallization inhibitors can notably delay such a process.

Renal lithiasis is a multifactorial disease. An important number of etiologic factors can be adequately modified through diet, since it must be considered that the urine composition is directly related to diet. In fact, the change of inappropriate habitual diet patterns should be the main measure to prevent kidney stones. In this paper, the relation between different dietary factors (liquid intake, pH, calcium, phosphate, oxalate, citrate, phytate, urate and vitamins) and each type of renal stone (calcium oxalate monohydrate papillary, calcium oxalate monohydrate unattached, calcium oxalate dihydrate, calcium oxalate dihydrate/hydroxyapatite, hydroxyapatite, struvite infectious, brushite, uric acid, calcium oxalate/uric acid and cystine) is discussed.

Background: The use of extracorporeal shock wave lithotripsy (ESWL) to treat calcium oxalate dihydrate (COD) renal calculi gives excellent fragmentation results. However, the retention of post-ESWL fragments within the kidney remains an important health problem. This study examined the effect of various urinary conditions and crystallization inhibitors on the regrowth of spontaneously-passed post-ESWL COD calculi fragments., Methods: Post-ESWL COD calculi fragments were incubated in chambers containing synthetic urine varying in pH and calcium concentration: pH = 5.5 normocalciuria (3.75 mM), pH = 5.5 hypercalciuria (6.25 mM), pH = 6.5 normocalciuria (3.75 mM) or pH = 6.5 hypercalciuria (6.25 mM). Fragment growth was evaluated by measuring increases in weight. Fragment growth was standardized by calculating the relative mass increase., Results: Calcium oxalate monohydrate (COM) crystals formed on COD renal calculi fragments under all conditions. Under pH = 5.5 normocalciuria conditions, only COM crystals formed (growth rate = 0.22 +/- 0.04 microg/mg x h). Under pH = 5.5 hypercalciuria and under pH = 6.5 normocalciuria conditions, COM crystals and a small number of new COD crystals formed (growth rate = 0.32 +/- 0.03 microg/mg x h and 0.35 +/- 0.05 microg/mg x h, respectively). Under pH = 6.5 hypercalciuria conditions, large amounts of COD, COM, hydroxyapatite and brushite crystals formed (growth rate = 3.87 +/- 0. 34 microg/mg x h). A study of three crystallization inhibitors demonstrated that phytate completely inhibited fragment growth (2.27 microM at pH = 5.5 and 4.55 microM at pH = 6.5, both under hypercalciuria conditions), while 69.0 microM pyrophosphate caused an 87% reduction in mass under pH = 6.5 hypercalciuria conditions. In contrast, 5.29 mM citrate did not inhibit fragment mass increase under pH = 6.5 hypercalciuria conditions., Conclusion: The growth rate of COD calculi fragments under pH = 6.5 hypercalciuria conditions was approximately ten times that observed under the other three conditions. This observation suggests COD calculi residual fragments in the kidneys together with hypercalciuria and high urinary pH values may be a risk factor for stone growth. The study also showed the effectiveness of specific crystallization inhibitors in slowing calculi fragment growth.

In this paper, we present a pilot study of the absorption of myo-inositol hexakisphosphate (InsP6) through the skin in humans. We found that, after topical treatment with a 4% InsP6 rich gel, InsP6 urinary excretion increased 54% compared to the control situation (participants submitted to an InsP6-poor diet for 15 days, n = 6), clearly demonstrating that InsP6 is absorbed through the skin of humans. These results demonstrate the topical application as a suitable administration route of InsP6 in humans.

Stress and anxiety of university science students (Chemistry) was evaluated in basal conditions and during exams using validated stress and anxiety questionnaires. The relations between the data obtained and various biochemical markers were established. Results showed that the evaluated students did not experience stress increase as a consequence of exams but suffered a significant increase in anxiety. The psychological findings agree with the urinary biomarkers studied. It is known that anxiety is related to partial magnesium reduction associated with a urinary magnesium excretion increase, as observed in the present data. Nevertheless, stress also correlates with a urinary calcium increase which was not detected in the present study.

Calcium oxalate monohydrate (COM) renal calculi can be classified into two groups: papillary and nonpapillary. In this paper, a comparative study between etiologic factors of COM papillary and nonpapillary calculi is performed. The study included 40 patients with COM renal calculi. The urine of these individuals was analyzed. Case history, lifestyle, and dietetic habits were obtained. No significant differences between urinary biochemical data of both groups were observed; 50% of COM papillary stone formers and 40% of COM nonpapillary stone formers had urolithiasis family history. A low consumption of phytate-rich products was observed for both groups. A relationship between profession with occupational exposure to cytotoxic products and COM papillary renal lithiasis was detected. The results suggest that COM papillary calculi would be associated to papillary epithelium alterations together with a crystallization inhibitors deficit, whereas COM nonpapillary calculi would be associated to the presence of heterogeneous nucleants and a crystallization inhibitors deficit.

Objectives: The monohydrate calcium oxalate lithiasis (MCO) is divided in two groups depending on the morphologic-crystal structure: papillary (anchorage point on a renal papilla lesion) and cavity (formed in a cavity with low urodynamic capacity). The minimal differences between urinary biochemistry of MCO makers in comparison with healthy population suggests that other factors different than urine biochemistry (professional activity, dietetic habits, systemic diseases) may be related with lithogenesis. The objective of this work is to study such factors, and compare them in both groups of MCO lithiasis (papillary and cavity)., Methods: We study 40 patients with MCO lithiasis (20 patients papillary and 20 patients cavitary). Medical history was performed (family history of lithiasis; associated diseases such as high blood pressure, diabetes, hyperuricemia, hypercholesterolemia, peptic ulcer disease; dietetic survey to evaluate phytate consumption; professions with high-risk of exposure to toxic agents); 24-hour urine biochemical tests, two-hour urine (pH), and serum biochemical profile were performed. Statistical analysis was performed using student's t test and chi-square., Results: There is a high prevalence of family history of renal lithiasis (45%) without differences between groups. There are not differences in urine or blood biochemical tests. There is a low consumption of phytate-containing foods in both groups, without significant differences. There is a trend to a greater exposure to cytotoxic agents in the papillary group (45%) vs. the cavity group (25%). Hypertension and hyperuricemia are more prevalent in the cavity MCO group (alpha = 0.025 and alpha = 0.010, respectively). Peptic ulcer disease is more prevalent in the papillary MCO group (alpha = 2.025). There are no significant differences in prevalence of hypercholesterolemia or diabetes mellitus between groups., Conclusions: Papillary MCO calculi are associated with a deficit of crystallization inhibitors (phytates), and disorders of the epithelium covering the renal papilla (cytotoxic agents exposure, peptic ulcer disease). Cavity MCO calculi are associated with a deficit of crystallization inhibitors (phytates) and a greater amount of heterogeneous nucleants (organic material induced by diseases such as hypertension, hyperuricemia, hyperglycemia, and hypercholesterolemia).

myo-Inositol hexaphosphate (InsP6) widely occurs in plant seeds. At present, some important benefits of InsP6 for human health have been described. The purpose of this study was to find the best condition for the optimum absorption of orally administered InsP6, evaluated by InsP6 urinary excretion. The influence of different stomach conditions (empty, empty with an alkalinizing agent, and full stomach) on the effects of oral administration of InsP6 and its urinary excretion was investigated in six healthy subjects on an InsP6-poor diet, given 400 mg of calcium/magnesium salt of InsP6 as a single dose. The basal urinary excretion of InsP6 on an InsP6-poor diet (50.91 +/- 15.09 microg) was significantly lower than that found when an InsP6-normal diet was consumed (100.09 +/- 26.42 microg) (P < .05). No differences were observed in the areas under the curve of accumulated excretion at 8 hours among the three different stomach conditions studied, suggesting that the overall InsP6 absorption took place independently of the stomach state (full or fasted) and indicating that the InsP6 absorption also takes place during the intestinal transit. Thus, if InsP6 supplements of vegetal origin are consumed to maintain the optimum InsP6 levels needed for a healthy status, these supplements can be consumed either during or between meals with the same efficacy.

Aim: The presence of uric acid in the beginning zone of different types of 'pure' calcium oxalate renal calculi was evaluated with the aim of establishing the degree of participation of uric acid crystals in the formation of such calculi., Methods: The core or fragment of different types of 'pure' calcium oxalate renal calculi was detached, pulverized and uric acid extracted. Uric acid was determined using a high-performance liquid chromatography/mass spectrometry method., Results: In calcium oxalate monohydrate (COM) papillary calculi with a core constituted by COM crystals and organic matter, 0.030+/-0.007% uric acid was found in the core. In COM papillary calculi with a core constituted by hydroxyapatite, 0.031+/-0.008% uric acid was found in the core. In COM unattached calculi (formed in renal cavities) with the core mainly formed by COM crystals and organic matter, 0.24+/-0.09% uric acid was found in the core. In COM unattached calculi with the core formed by uric acid identifiable by scanning electron microscopy (SEM) coupled to X-ray microanalysis, 20.8+/-7.8% uric acid was found in the core. In calcium oxalate dihydrate (COD) unattached calculi containing little amounts of organic matter, 0.012+/-0.004% uric acid was found. In COD unattached calculi containing little amounts of organic matter and hydroxyapatite, 0.0030+/-0.0004% of uric acid was found., Conclusions: From these results it can be deduced that uric acid can play an important role as inducer (heterogeneous nucleant) of COM unattached calculi with the core formed by uric acid identifiable by SEM coupled to X-ray microanalysis (these calculi constitute the 1.2% of all calculi) and in COM unattached calculi with the core mainly formed by COM crystals and organic matter (these calculi constitute the 10.8% of all calculi).

Calcification is an undesirable disorder, which frequently occurs in the heart vessels. In general, the formation of calcific vascular lesions involves complex physicochemical and molecular events. Calcification (hydroxyapatite) is initiated by injury and is progressed by promoter factors and/or the deficit of inhibitory signals. Myo-inositol hexakisphosphate (phytate, InsP6) is found in organs, tissues and fluids of all mammals and exhibits an important capacity as a crystallization inhibitor of calcium salts in urine and soft tissues. The levels found clearly depend on the dietary intake but it can also be absorbed topically. In this paper, the capacity of InsP6 as a potential inhibitor of cardiovascular calcifications was assessed in Wistar rats. Three groups were included, a control group, an InsP6 treated group (subjected to calcinosis induction by Vitamin D and nicotine and treated with standard cream with a 2% of InsP6 as potassium salt) and an InsP6 non-treated group (only subjected to calcinosis induction). All rats were fed AIN 76-A diet (a purified diet in which InsP6 is undetectable). Animals were monitorized every 12 hours. After 60 hours of calcinosis treatment, all rats of the InsP6 non-treated group died and the rest were sacrificed. Aortas and hearts were removed. A highly significant increase in the calcium content of aorta and heart tissue was observed in the InsP6 non-treated rats (21 +/- 1 mg calcium/g dry aorta tissue, 10 +/- 1 mg calcium/g dry heart tissue) when compared with controls (1.3 +/- 0.1 mg calcium/g dry aorta tissue, 0.023 +/- 0.004 mg calcium/g heart dry tissue) and InsP6 treated (0.9 +/- 0.2 mg calcium/g dry aorta tissue, 0.30 +/- 0.03 mg calcium/g dry heart tissue) animals. Only InsP6 non-treated rats displayed important mineral deposits in aorta and heart. These findings are consistent with the action of InsP6, as an inhibitor of calcification of cardiovascular system.

A very simple and direct method for determination of uric acid, in various biological matrices, based on high-performance liquid chromatography and mass spectrometry is described. Chromatographic separations were performed with a stationary phase Zorbax Sax Column, an anion exchange resin, with 50% sodium citrate 1 mM at pH 6.5 and 50% acetonitrile as mobile phase delivered at a flow rate of 1 ml/min. The detector counted negative ions by monitoring m/z 167.1, which corresponds to the urate anion. The method does not use an internal standard but quality control samples were used. Intra-day precision ranged between 1.1 and 1.5%, whereas inter-day precision was between 1.3 and 2.8% (n=5) working with some selected standards. Recovery tests of added standard have been successfully performed in urine and saliva samples, thus showing an appropriate accuracy of the method. The limit of quantitation found was 70 microg/l. Different urine and saliva samples were analyzed using an alternative analytical methodology based on an enzymatic reaction and photometric detection at 520 nm, resulting both methods comparable at a 95% confidence level. The method has been also applied to the determination of trace amounts of uric acid in the core of some selected calcium oxalate renal calculi.

Broncholiths, which usually arise from calcified peribronchial lymph nodes, can be found by radiography or bronchoscopy. We describe the case of a 19-year-old man who had experienced lithoptysis of bronchial hydroxyapatite calculi for over 6 months and who reported having sandy expectoration since childhood. Exhaustive clinical, radiographic, and endoscopic diagnostic studies detected no calcified lesions in the thorax that could explain the origin of the broncholiths. Therefore, we propose that broncholiths may form by mechanisms similar to those involved in calculi formation in other locations.

Background: Calcinosis cutis is a disorder caused by abnormal deposits of calcium phosphate in the skin and is observed in diverse disorders. Myo-inositol hexaphosphate (InsP(6)) is a diet-dependent molecule found in all mammalian fluids and tissues, which exhibits an extraordinary capacity as a crystallization inhibitor of calcium salts., Objectives: To establish the effects of topically administered InsP(6) cream on artificially provoked dystrophic calcifications in soft tissues., Methods: Fourteen male Wistar rats were randomly assigned into two groups: control and treated groups. Rats were fed with an InsP(6)-free or phytate diet. Plaque formation was induced by subcutaneous injection of 0.1% KMnO(4) solution. From 4 days before plaque induction to the end of the experiment, control rats were treated topically with a standard cream, whereas treated rats were treated with the same cream with 2% InsP(6) or phytate (as sodium salt). Calcification of plaques was allowed to proceed for 10 days. InsP(6) in urine was determined. The plaques were excised and weighed., Results: It was found that when InsP(6) was administered topically through a moisturizing cream (2% InsP(6)-rich), the plaque size and weight were notably and significantly reduced compared with the control group (1.6 +/- 1.1 mg InsP(6)-treated, 26.7 +/- 3.0 mg control). The InsP(6) urinary levels for animals treated with the InsP(6)-enriched cream were considerably and significantly higher than those found in animals treated topically with the cream without InsP(6) (16.96 +/- 4.32 mg L(-1) InsP(6)-treated, 0.06 +/- 0.03 mg L(-1) control)., Conclusions: This demonstrates the important capacity of InsP(6) as a crystallization inhibitor and also demonstrates that it is possible to propose topical use as a new InsP(6) administration route.

Study Design: Clinical case report with comments by colleagues from Sweden, Poland, Spain, Brazil, Japan, Belgium and Switzerland., Objectives: To discuss the role of disodium etidronate therapy for prevention of calcium phosphate vesical calculi in persons with spinal cord injury, who have hypercalciuria and biochemical evidence of increased bone resorption., Setting: Regional Spinal Injuries Centre, Southport, UK., Methods: A 21-year-old male sustained paraplegia (T-10; ASIA scale: A) in a road traffic accident in June 2001. He had an indwelling urethral catheter until the end of August 2001, when he started self-catheterisation. He developed bladder stones and electrohydraulic lithotripsy (EHL) was performed in May 2002. All stone fragments were removed. Recurrence of vesical calculi was noted in October 2002. These stones were fragmented by lithoclast lithotripsy in two sessions, in December 2002 and February 2003; all stone fragments were removed at the end of the second session. This patient reverted to indwelling catheter drainage when vesical calculi recurred. In September 2003, X-ray of the abdomen showed recurrence of vesical calculi. By February 2004, the stones had increased in size and number. EHL of vesical calculi was again performed in April 2004. Complete clearance was achieved., Results: A 24-h urinalysis detected hypercalciuria--18.7 mmol/day (reference range: 2.5-7.5). Biochemical analysis of vesical calculus revealed calcium phosphate (85%) and magnesium ammonium phosphate (15%). Plasma C-terminal telopeptide (CTX) was increased - 1.06 ng/ml (reference range: 0.1-0.5 ng/ml). Free deoxypyridinoline/creatinine ratio (fDPD/Cr) in urine was also increased - 20.2 (reference range: 2.3-5.4). In April 2004, this patient was prescribed disodium etidronate 400 mg day. Nearly 3 months after commencing therapy with etidronate, plasma CTX decreased to 0.87 ng/ml. fDPD/Cr in urine also decreased to 12.4. After 4 months of etidronate therapy, 24-h urinary calcium excretion had decreased to 6.1 mmol/day., Conclusion: Etidronate (400 mg daily) is a very effective inhibitor of calcium phosphate crystallisation. Etidronate decreased urinary excretion of calcium, an important factor in prevention of calcium phosphate bladder stones. Etidronate therapy is not a substitute for other well-established methods for prevention of vesical calculi in spinal cord injury patients, for example, large fluid intake, avoiding long-term catheter drainage. Intermittent therapy with etidronate may be considered in selected patients, in whom hypercalciuria persists after instituting nonpharmacological therapy for an adequate period, for example, early mobilisation, weight-bearing exercises, and functional electrical stimulation. However, possible side effects of etidronate, and the fact that etidronate is not licensed in United Kingdom for prevention of urolithiasis, should be borne in mind.

Urine contains variable amounts of organic matter derived from cell degradation. The cellular detritus is composed by membranous and cytosolic glycoproteins, etc. The aim of this paper was to study the role of organic matter in calcium oxalate crystal development and to evaluate the action of some crystallization inhibitors on this process. Crystallization studies were carried out on urine in stagnant urine as well as under flow conditions, in presence and absence of cellular debris. Low amounts of cellular debris (when batch conditions were used), exhibited some inhibitory activity on heterogeneous nucleation of calcium oxalate monohydrate crystals, probably due to glycoproteins. Increasing amounts of cellular debris, however, promoted the nucleation of calcium oxalate monohydrate crystals. When cellular debris was retained in a cavity with a urine flow, this organic matter effectively induced the development of primary aggregates of calcium oxalate monohydrate crystals (crystallization range 2.8 mg/h per mg of organic matter). Presence of crystallization inhibitors prevented or minimized crystal development. These findings show that cell debris provides the necessary elements for the development of oxalate crystals and that this process can be effectively inhibited by presence of crystallization inhibitors.

The presence of myo-inositol hexakisphosphate (InsP6) in biological fluids (blood, urine, saliva, interstitial fluid) of mammalians has been clearly demonstrated. The existence of intracellular InsP6 in mammalian cells has also been established. Further, significant extracellular and intracellular functions of this molecule have been found. The relationship between InsP6 ingestion and the InsP6 distribution in various tissues of mammalians is discussed. It was found that the majority of the extracellular InsP6 found in organs, tissues and biological fluids of mammalians has a dietary origin and is not a consequence of endogenous synthesis, whereas the intracellular InsP6 probably originates in the cell. Little absorption of dietary InsP6 takes place during intestinal transit and depletion of extracellular InsP6 occurs at high rates when InsP6-poor diets are consumed. From these results, it can be deduced that health benefits linked to extracellular InsP6 must be related to dietary InsP6.

Recently, some properties of myo-inositol hexakisphosphate (InsP(6)) are related to its dermatological use as discolouring agent, on preventing calcinosis cutis or due to its important role on premature aging. Some studies also seem to demonstrate a capacity of InsP(6) to inhibit skin cancer. In this paper, a first study of the absorption of InsP(6) through the skin is developed. Due to the correlation between InsP(6) absorption and its urinary excretion, these last values were used to evaluate this process. It was found that using a moisturizing cream as vehicle, the InsP(6) sodium salt was absorbed at significantly higher amounts than the InsP(6) calcium-magnesium salt. Maximum InsP(6) urinary concentrations were observed approximately at 14 d of 2% InsP(6) topical cream application, and gave 66.35+/-5.49 mg/l urinary InsP(6) when the sodium salt was used and 16.02+/-2.61 mg/l urinary InsP(6) when the calcium-magnesium salt was applied. When the InsP(6) topical cream administration ceased, the InsP(6) urinary excretion fell dramatically approximately during a period of 10 d. From these results, it can be deduced that by topical administration InsP(6) can achieve important concentrations in tissues and biological fluids, this demonstrating that it is possible to propose the topic use as a new InsP(6) administration route.

The main objective of this paper was to study residual lithiasis after extracorporeal shock wave lithotripsy (post-ESWL), with the aim of contributing to the development of effective prophylactic measures. In vivo regrown calcium oxalate monohydrate (COM) post-ESWL residual fragments were studied by stereoscopic microscopy, infrared spectroscopy and scanning electron microscopy with an energy dispersive X-ray analyzer. An in vitro system was also used to study the regrowth of post-ESWL fragments of COM calculi. The regrowth was evaluated as the relative increase in the weight of the fragments. The effects of a calcium oxalate crystallization inhibitor (phytate) were also evaluated. All of the in vivo regrown COM real residual post-ESWL fragments exhibited practically the same internal structural features. The in vitro studies demonstrated that the regrowth of post-ESWL residual fragments, in the absence of crystallization inhibitors, occurred even using normocalciuric/normooxaluric urine and could be detected at 24 h. At 144-240 h, the formation of new COM columnar zones was observed. The presence of 1.5 mg/l of phytate totally blocked the growth process. When hypercalciuric/normooxaluric urine was used, significant amounts of disorganized calcium oxalate dihydrate (COD) crystals were formed. The in vitro regrowth of post-ESWL COM fragments was clearly influenced by the presence of crystallization inhibitors. These data also demonstrate the importance that effective prophylactic therapies could exert on preventing recurrence.

Myo-inositol hexakisphosphate (InsP6, phytate) is a molecule to which diverse beneficial properties have been attributed. Some of these properties are related to its dermatological use as discolouring agent, on preventing calcinosis cutis or due to its important role on premature aging. Other studies also seem to demonstrate a capacity of InsP6 to inhibit skin cancer. In this paper, the effect of the vehicle of topical administration of phytate is studied, using four groups of male Wistar rats (n = 6) fed with an InsP6 defficient diet and treated with a hydrophyl gel or an O/W moisturizing cream with two different concentrations of InsP6. Due to the correlation between InsP6 absorption and its urinary excretion, these last values were used to evaluate this process. It was found that phytate was absorbed through the skin using both a gel or a cream, demonstrating that its absorption is independent on the matrix used for topical treatment. However, urinary InsP6 values were slightly higher when using the gel, but in all cases values were much higher than those found with oral InsP6 treatment, due to the formation of insoluble species in the gastrointestinal tract when InsP6 is administered orally.

Objective: The exact mechanism of renal stone formation is still not totally understood. Thus, the role of crystallization inhibitors at different stages of stone development, the influence of preexisting solid particles and the effects of variations in urine composition require further clarification. The aim of this paper is to clarify some of these questions by studying the regrowth achieved by real spontaneously passed post-extracorporeal shock wave lithotripsy (post-ESWL) fragments of calcium oxalate monohydrate (COM) renal calculi., Material and Methods: An in vitro system was used to study the regrowth of post-ESWL fragments of COM calculi, which was defined as the relative increase in weight of the fragments., Results: It was found that new columnar zones of COM crystals were formed under normal calcium and oxalate urinary conditions and no calcium phosphates were observed, in spite of the urinary pH being >6. The presence of 3.03 microM phytate totally blocked these crystal growth processes. When hypercalciuric urine was used at a pH of 6.5, large brushite crystals and zones totally covered by hydroxyapatite were observed for short periods, and zones containing calcium oxalate dihydrate crystals could be observed for longer periods. In such cases, 9.09 microM phytate totally blocked the growth processes, 69.0 microM pyrophosphate caused a reduction in calculi growth of 93% and 5.35 mM citrate caused no inhibitory effects., Conclusion: The results show that when crystallization inhibitors were absent, the growth of calcium oxalate calculi fragments took place even under normal urine conditions, clearly demonstrating the importance of crystallization inhibitors in avoiding or delaying calculi development.

Background: The combination of indinavir, a protease inhibitor, and reverse-transcriptase inhibitors is widely used in the treatment of HIV-1 infection. However, precipitation of indinavir crystals in the renal tubular lumen due to the drug's aqueous insolubility may result in characteristic symptoms of flank pain or classic renal colic. An in vitro study has shown that addition of escin to synthetic urine containing indinavir delayed the crystallization time of indinavir., Objective: This study examined the efficacy and tolerability of the addition of escin to highly active antiretroviral therapy containing indinavir to delay the crystallization time of indinavir in urine., Methods: This was a multicenter, randomized, open-label, controlled, 4-period crossover trial in which each period lasted 4 weeks. HIV-1-infected adults receiving treatment with indinavir plus 2 nucleoside analogue reverse-transcriptase inhibitors in whom plasma viral loads had been undetectable (HIV-1 RNA <200 copies/mL) for at least 6 months were randomly assigned to 1 of 2 groups based on the timing of the initiation of escin. Group I received escin during the second and third treatment periods, and group II received escin during the first and fourth treatment periods. The primary end point was the in vitro crystallization time of indinavir in 24-hour urine specimens, determined at the end of each 4-week period. Tolerability was assessed based on the number of patients with a rebound in plasma viral load and on the numbers of clinically and biologically relevant adverse events (including those requiring discontinuation of treatment). Clinical and laboratory evaluations were performed throughout each 4-week period., Results: Fifty HIV-1-infected patients were enrolled, 47 were randomized to treatment (40 [85.1%] men, 7 [14.9%] women; median [interquartile range] age, 36 [34-45] years), and 30 completed the study. Urine pH and plasma and urine indinavir concentrations were unaffected by the addition of escin to antiretroviral treatment. The mean time to the onset of crystallization was 14.7 minutes with escin (95% Cl, 11.8-17.5) and 9.9 minutes without it (95% Cl, 6.7-13.1). Therefore, the addition of escin increased the mean crystallization time by 5.5 minutes (95% Cl, 1.5-9.5; P = 0.008), representing the overall capacity of study treatment to inhibit indinavir crystallization in the urine. Three of 47 patients had mild gastrointestinal symptoms associated with escin treatment. No episodes of nephrolithiasis were recorded during the study or after the completion of study treatment., Conclusion: The results of this prospective clinical trial of the effect of escin on indinavir crystallization time support the possibility that indinavir-associated nephrolithiasis may be prevented by means other than overhydration. Further research is needed in greater numbers of patients over longer follow-up times.

Objective: To assess the effects of a glycoprotein (mucine) on calcium oxalate crystal development in different conditions and situations, to clarify some of its possible effects., Materials and Methods: Crystallization was assessed using a batch system in presence of mucine suspensions, by kinetic-turbidimetric measurements, and using a flow system in the presence of retained agglomerates of mucine, evaluating the precipitated calcium oxalate., Results: In batch conditions low mucine concentrations (<15 mg/L) inhibited calcium oxalate nucleation and higher concentrations (<250 mg/L) inhibited calcium phosphate nucleation, whereas at high concentrations there was also promotion. The presence of an aggregate of mucine in the flow system provoked calcium oxalate monohydrate crystallization at 0.691 microg/h per mg of mucine. In flow conditions pyrophosphate at 11.5 micromol/L caused a decrease of 84% in the calcium oxalate crystallized on mucine, 1.32 mmol/L of citrate a decrease of a 83%, 20 mg/L of pentosan polysulphate a decrease by 80%, and 7.58 micromol/L phytate totally prevented the crystallization of calcium oxalate on mucine., Conclusion: All substances inhibiting calcium oxalate crystallization with the capacity to interact with calcium ions also have crystallization promoting properties when they are at sufficiently high concentrations, because of their capacity to form agglomerates or the insolubility of their calcium salts.

Myo-inositol hexaphosphate (InsP6) is an abundant component of plant seeds. It is also found in significant levels in blood and mammalian tissues, but they are totally dependent on their dietary intake. In the present paper, we describe studies on the effect of InsP6 on a model of dystrophic calcification, which was chemically induced by subcutaneous injection of a 0.1% KMnO4 solution. Male Wistar rats were randomly divided into four groups for treatment over 31 days. A: animals consuming a purified diet in which InsP6 was absent but to which 1% of InsP6 (as sodium salt) was added. In this group, the InsP6 plasma levels (0.393 +/- 0.013 microM) were similar to those observed in rats consuming a standard diet. B: animals consuming only the purified diet in which InsP6 was absent. In this case the InsP6 plasma levels decreased (0.026 +/- 0.006 microM); C: animals consuming the same purified diet as group B but received daily subcutaneous injections of 50 microg kg(-1) etidronate during the last 14 days. In this case the InsP6 plasma levels were also very low (0.025 +/- 0.007 microM); D: animals consuming the same diet as group B but a 6% of carob germ (InsP6 rich product) was added. The InsP6 plasma levels (0.363 +/- 0.035 microM) were also similar to those observed in rats consuming a standard diet. After 21 days plaque formation was induced. Calcification plaques were allowed to proceed for 10 days, after which the plaque material present was excised, dried and weighed. It was found that the presence of myo-inositol hexaphosphate (phytate) in plasma at normal concentrations (0.3-0.4 microM) clearly inhibited the development of dystrophic calcifications in soft tissues. These results demonstrates that myo-inositol hexaphosphate acts as an inhibitor of calcium salt crystallization.

Due to the absence of HPLC methods to determine myo-inositol using mass detection and considering its sensitivity and selectivity, a high performance liquid chromatography-mass spectrometry method for the analysis of myo-inositol is described and applied to its direct determination in urine and saliva samples. Successful resolution of myo-inositol and its related substances was achieved with a stationary phase Aminex HPX-87C Column with milli-Q water as mobile phase and 5 mM ammonium acetate added post-column. The detector counted positive ions by monitoring m/z = 198, which corresponds to the myo-inositol adduct with ammonium cation. Urine and saliva samples were previously purified by passing through an anion-exchange resin. Concentrations as low as 138 and 461 microg/l in saliva and urine could be respectively quantified. Intra-day R.S.D. ranged from 0.83 to 1.02%, whereas inter-day R.S.D. was between 1.54 and 3.58%.

In this paper the relation between long term consumption of a high dose of sodium phytate and the mineral status of the organism is evaluated in rats. For this purpose, element concentrations (Ca, Mg, Fe, Zn, Mn) were determined in liver, heart, testicle, bone and urine of a second generation of Wistar rats, treated with a phytate free diet (AIN-76A) and with the same diet plus 1% phytate as sodium salt. The most significant differences were observed between bone zinc contents of male and female rats. The zinc content of rats fed a 1% phytate as sodium salt diet resulted clearly lower than that found in no-phytate treated rats. Hence, it is concluded that when up to 1% of phytate as sodium salt is consumed together with an equilibrated purified diet (free of phytate), no decrease in mineral bioavailability is observed in second generation rats, except for an indication of lower zinc availability by lower zinc concentrations in some organs, mainly bone. However, using this purified diet, the zinc concentration in bone resulted around 10 times higher than found in rats fed with a common non purified rat chow.

Background: Phytate as sodium salt has been used at high doses to treat stone-former patients with idiopathic hypercalciuria. The experimental and clinical hypocalciuric effects of dietary fiber have also been assigned to the presence of phytate as calcium-magnesium salt (phytin). As a consequence of the additional interest in phytate due to its capacity as crystallization inhibitor, now a study of the effects of potassium phytate on urinary calcium excretion is presented and compared with the effects caused by other phytate salts., Methods: To study the effect of calcium-magnesium phytate, 36 Wistar rats (6 groups) were fed with a purified diet in which phytate was practically absent (4068.02 Reference Diet). Three groups were fed with increasing calcium amounts and with the same amount of phytin, each one corresponding to one control group. To study the effects of magnesium-potassium, sodium and potassium phytate salts, 48 Wistar rats (8 groups) were fed with UAR-A04 diet (a standard diet which contains 0.8% of phytin). Two control groups fed with low and high calcium amounts and 6 treated groups were formed. The effect of the dose of potassium phytate on urinary calcium was carried out using 2 additional groups of 6 Wistar rats each one fed with UAR-A04 diet and increasing amounts of potassium phytate., Results: No significant changes in urinary calcium were observed when phytin (calcium-magnesium phytate) was supplied. The urinary calcium was clearly reduced by the three phytate salts assayed (magnesium-potassium, sodium, potassium), but the most significant decrease was noticed when the potassium phytate salt was administered. Phytate administration, independently of the salt or dose used, did not significantly affect the urinary oxalate., Conclusion: It can be clearly deduced that the effects of phytate on the urinary parameters, mainly calcium, fundamentally depend on the type of salt used. Thus, the most remarkable effects on urinary calcium reduction were caused by the potassium salt. Obviously, these findings must be confirmed in human studies., (Copyright 2004 S. Karger AG, Basel)

Background: Sialolithiasis is a common disease of salivary glands. The etiology of these calculi is little known and their exact mechanism of formation is unknown., Methods: The composition and structure of 21 sialoliths were studied and the composition of the saliva of each corresponding patient was determined (pH, calcium, magnesium, phosphorus, citrate and phytate)., Results: Eighteen sialoliths exhibited similar macro and microstructure, being constituted by hydroxyapatite (HAP) and organic matter, normally arranged in a multilayer structure. The three remaining sialoliths were exclusively constituted by organic matter. The salivary Ca of patients with HAP calculi was significantly higher than that found in the saliva of the healthy group. The salivary phytate concentration of patients with HAP calculi was significantly inferior to that found in patients with calculi exclusively formed by organic matter, as well as to that found in saliva of healthy group. Significant differences between the salivary magnesium concentrations of patients with HAP calculi and the control group were also observed. No significant differences between pH and citrate concentrations of the three groups were found., Conclusions: It was concluded that the deficit of crystallization inhibitors such as myo-inositol hexaphosphate (phytate) was also an important etiologic factor implied in the sialolith development.

Two flow methods for the enzymatic determination of pyrophosphate are described that are used to diminish the consumption of reagents. One method is based on the use of an open-close circuit with manual injection using a syringe. The other is a sequential injection method. The analytical features of both methods are: a linear range of 0.4 - 20 mg L(-1), an LOD of 0.38 mg L(-1), and a CV of 2.0% for the sequential injection method, and a linear range of 0.3 - 15 mg L(-1), an LOD of 0.29 mg L(-1), and CV of 2.2% for the open-close circuit method. The methods were applied to the determination of pyrophosphate in urine. The pyrophosphate concentration determined in urine samples varied from 1.26 to 6.67 mg L(-1).

A capillary electrophoresis (CE) method with indirect photometric detection was developed to identify and quantify myo-inositol phosphates in food samples. A flow-injection (FI) system including a micro-column containing anionic exchange resin was used for the solid-phase extraction of the myo-inositol phosphates with a view to their preconcentration. The FI system was automatically coupled to CE equipment via a mechanical interface. The overall analysis time was shortened by incorporating an FI system for myo-inositol hexakisphosphate monitoring. The limit of detection for myo-inositol phosphates as determined by FI-CE ranged from 11 to 26 micromol/L and the coefficient of variation from 3.9 to 5.0%. On the other hand, the limit of detection and coefficient of variation for myo-inositol hexakisphosphate as monitored by the FI system were 75 micromol/L and 2.9%, respectively. The proposed method was successfully applied to a variety of food samples with recoveries ranging from 96.0 to 107.7% and the precision from 3.9 to 7.9%. Based on the results, the content of myo-inositol hexakisphosphate in nuts was two or three times higher than that in legumes.

Objective: It is well known that all renal stones are associated with a high recurrence rate. The aim of this paper is to study the different types of renal calculi recurrence., Material and Methods: The study included 220 patients who had produced two or more renal calculi over a period of <5 years (total 634 calculi). The procedure used to study renal calculi involved appropriate combinations of stereoscopic microscopy with infrared spectrometry and scanning electron microscopy coupled with X-ray microanalysis., Results and Conclusion: Recurrent stone-formers can be classified into two large groups: those who always produce the same type of calculus (the most common type of recurrence was calcium oxalate dihydrate, followed by calcium oxalate monohydrate non-papillary and calcium oxalate monohydrate papillary calculi); and those who produce different types of renal calculi (the most frequent recurrences in this group were the changes calcium oxalate dihydrate-->calcium oxalate dihydrate/hydroxyapatite and calcium oxalate monohydrate-->calcium oxalate dihydrate).