A simple and rapid colorimetric method for determination of phytate in urine.

Phytate is a natural product present in urine and biological fluids that is associated with health benefits, such as the prevention of calcium renal stone formation. The available methods for phytate analysis in urine all require elaborate instrumentation and cannot be routinely applied in clinical laboratories. Here, we describe a simple procedure for urinary phytate determination, employing colorimetric detection. Our method requires purification and preconcentration of phytate via solid-phase extraction prior to colorimetric detection employing Fe(III)-thiocyanate. The working linear range of the assay is 0-5 µM phytate. The limit of detection is 0.055 µM. The relative standard deviation obtained upon assay of samples containing 2 µM phytate was 3.5 %. Several urine samples were analyzed using an alternative method based on the detection of phosphorus; the results of the two assays were comparable. Our novel method of phytate analysis in human urine is simple, rapid (3 h for 10 samples), accurate, precise, reliable, and highly sensitive. The assay can be run in most analytical laboratories and does not require sophisticated instrumentation.

Urinary pH and renal lithiasis.

Formation of calcium oxalate crystals, either as monohydrate or dihydrate, is apparently unrelated to urinary pH because the solubilities of these salts are practically unaltered at physiologic urinary pH values. However, a urinary pH <5.5 or >6.0 may induce uric acid or calcium phosphate crystals formation, respectively, which under appropriate conditions may induce the development of the calcium oxalate calculi. We assessed the relationship between the urinary pH and the formation of different types of calculi. A retrospective study in 1,478 patients was done. We determined the composition, macrostructure, and microstructure of the calculi and the urinary pH, 50.9% of calcium oxalate monohydrate unattached calculi were present in patients with urinary pH <5.5. We found that 34.1 and 41.5% of calcium oxalate dihydrate calculi were present in patients with urinary pH <5.5 and >6.0, respectively. Infectious calculi were found primarily in patients with urinary pH >6.0 (50.7%). Only calcium oxalate monohydrate papillary calculi were associated with urinary pH between 5.5 and 6.0 (43.1%). Urine of pH <5.5 shows an increased capacity to develop uric acid crystals, which can act as a heterogeneous nuclei of calcium oxalate crystals. In contrast, urine of pH >6.0 has an increased capacity to develop calcium phosphate crystals, which can act as a heterogeneous nuclei of calcium oxalate crystals. Oxalate monohydrate papillary calculi were associated to pH between 5.5 and 6.0 because the injured papilla acts as a heterogeneous nucleant. Consequently, measurement of urinary pH may be used to evaluate the lithogen risk of given urine.

[Update on the current role of plasma cholinesterase]. / Papel de las colinesterasas plasmáticas. Actualización.

The antagonism of steroidal nondepolarizing neuromuscular blockers (NDMBs) moved forward recently with the introduction of sugammadex, the only drug able to immediately reverse the effects of curarization produced by NDMBs. This advance has necessitated reflection on the future role of pseudocholinesterase. In spite of the side effects of succinylcholine and published opinions on its use, this NDMB continues to be used in clinical anesthesia. Pseudocholinesterase is mainly found in the liver, plasma, and nervous system. The enzyme is synthesized in the liver in greater amounts than required although certain conditions lead to deficiency, which is usually asymptomatic. The only clinical expression is the apnea which develops after administration of succinycholine because this NDMB cannot be metabolized. In some patients, slight reductions in the antagonism of succinylcholine lead to rising neuromuscular concentrations of the drug in accordance with the degree and duration of the blockade. We review the various forms of pseudocholinesterase deficiency, including a discussion of genetic variants, clinical manifestations, and management. In addition to discussing the diagnosis of this condition and the clinical implications, we highlight the importance of practice protocols and access to a referral laboratory if one is not available within the immediate hospital.

Papel de las colinesterasas plasmáticas. Actualización / Update on the current role of plasma cholinesterase

Las novedades recientemente manifestadas en el campo de la antagonizacion de los relajantes neuromusculares no despolarizantes (BNMND) esteroideos, nos ha hecho revisar cual es o seguirá siendo en el futuro el rol que realizaran las enzimas plasmáticas seudocolinesterasas (CP SC) Con la introducción del sugamadex única molécula capaz de antagonizar de forma inmediata los efectos de la curarizacion producida por este tipo de bloqueantes neuromusculares (BNM) A pesar de sus efectos colaterales y la opinion encontrada de numerosos autores, la succinilcolina (SCH) sigue siendo un bloqueante neuromuscular despolarizante (BNMD) utilizado en el mundo de la anestesia clínica. La colinesterasa plasmática (CP), se encuentra presente principalmente en el hígado, plasma y sistema nervioso. Es sintetizada en el hígado en cantidades supriores a las necesarias. Asimismo puede presentarse en cantidades menores en diferentes situaciones patológicas. Los pacientes con déficit de CP son generalmente asintomáticos, y sólo tiene expresión clínica, mediante la aparición de apnea succinilcolínica, tras la administración de succinilcolina, por imposibilidad de metabolizar este fármaco. En algunos sujetos pequeñas disminuciones de la inactivación de la succinilcolina, producen un gran incremento del fármaco en la placa neuromuscular, del grado y duración del bloqueo. En esta revisión hacemos un repaso de los déficit de CP sus diferentes alteraciones por variantes genéticas, su clínica y su tratamiento. Además de sus implicaciones clínicas y método de diagnostico sin olvidar la importancia de tener elaborados protocolos de actuación y posibilidad de tener un laboratorio de referencia si no se determinan en nuestro medio hospitalario(AU)

The antagonism of steroidal nondepolarizing neuromuscular blockers (NDMBs) moved forward recently with the introduction of sugammadex, the only drug able to immediately reverse the effects of curarization produced by NDMBs. This advance has necessitated reflection on the future role of pseudocholinesterase. In spite of the side effects of succinylcholine and published opinions on its use, this NDMB continues to be used in clinical anesthesia. Pseudocholinesterase is mainly found in the liver, plasma, and nervous system. The enzyme is synthesized in the liver in greater amounts than required although certain conditions lead to deficiency, which is usually asymptomatic. The only clinical expression is the apnea which develops after administration of succinycholine because this NDMB cannot be metabolized. In some patients, slight reductions in the antagonism of succinylcholine lead to rising neuromuscular concentrations of the drug in accordance with the degree and duration of the blockade. We review the various forms of pseudocholinesterase deficiency, including a discussion of genetic variants, clinical manifestations, and management. In addition to discussing the diagnosis of this condition and the clinical implications, we highlight the importance of practice protocols and access to a referral laboratory if one is not available within the immediate hospital(AU)

Anticalculus effect of a triclosan mouthwash containing phytate: a double-blind, randomized, three-period crossover trial.

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.

Absorption of myo-inositol hexakisphosphate (InsP6) through the skin in humans.

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.

Influence of concomitant food intake on the excretion of orally administered myo-inositol hexaphosphate in humans.

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.

Intracellular and extracellular myo-inositol hexakisphosphate (InsP6), from rats to humans.

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.

Study of a myo-inositol hexaphosphate-based cream to prevent dystrophic calcinosis cutis.

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.

Effect of phytate on element bioavailability in the second generation of rats.

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.

Study of potassium phytate effects on decreasing urinary calcium in rats.

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.

Dietary myo-inositol hexaphosphate prevents dystrophic calcifications in soft tissues: a pilot study in Wistar rats.

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.

Factores psicosociales en el manejo de pacientes con enfermedad respiratoria / Psychosocial factors in managing patients with respiratory disease

En la atención primaria y en la atención especializada, la intervención psicológica a menudo va encaminada a controlar los factores psicosociales que aparecen en las alteraciones psicológicas, pero también, como es nuestro caso, en los factores psicosociales que interaccionan con las enfermedades médicas. Hay que tener en cuenta la alta proporción de pacientes con enfermedad pulmonar que acuden a las consultas y que muchos de ellos tienen experiencias psicosomáticas relacionadas con la enfermedad pulmonar. La fatiga, las preocupaciones acerca de los síntomas, la percepción de disminución de la calidad de vida, la ansiedad e incluso el pánico son factores psicosociales que predisponen al paciente a confundir la interpretación de los síntomas que están asociados a su patología; incluso pueden situarlo frente a una predisposición a la hiperventilación y hacerlo más sensible a su enfermedad. Hace varios años que se puso de relieve la relación entre la fisiología respiratoria y la ansiedad asociada al pánico y se han explorado algunas dificultades en el manejo de este tipo de ansiedad en pacientes con enfermedad pulmonar tipo obstrucción crónica la flujo aéreo. Aquí se propone orientar el manejo del enfermo respiratorio hacia la educación y entrenamiento en el reconocimiento de síntomas y la intervención psicosocial, incluyendo técnicas de relajación, de respiración y de reestructuración cognitiva, porque constituyen un complemento a la medicación y en su conjunto son un soporte de considerable importancia que ayudan al paciente en la mejora de la percepción de su calidad de vida, y el autocontrol de su enfermedad. (AU)

Absorption and excretion of orally administered inositol hexaphosphate (IP(6) or phytate) in humans.

A study of the pharmacokinetic profile (oral absorption and renal excretion) of inositol hexaphosphate or phytate (IP(6)) is presented. Seven healthy volunteers were following a IP(6) poor diet (IP(6)PD) in a first period, and on IP(6) normal diet (IP(6)ND) in a second one. When following the IP(6)PD they become deficient in IP(6), the basal levels found in plasma (0.07+/- 0.01 mg/L) being clearly lower than those found when IP(6)ND was consumed (0.26+/- 0.03 mg/L). During the restriction period the maximum concentration in plasma were obtained 4 h after the ingestion of a single dose of IP(6), observing almost the same renal excretion profiles for the three different commercial sources and doses. After the IP(6) restriction period, volunteers were on IP(6)ND, reaching normal plasma and urinary IP(6) values in 16 days. Thus, the normal plasma and urinary concentrations, can be obtained either by consumption of a IP(6)ND taking a long time or in a short period by IP(6) supplements.

Phytate levels in diverse rat tissues: influence of dietary phytate.

Phytate (inositol hexaphosphate; InsP6) was determined in rat tissues fed on diets with different phytate contents, using a GC-mass detection methodology that permitted the evaluation of the total amount of this substance present in such tissues. The highest InsP6 concentrations were found in brain 5.89 x 10(-2)(SE 5.7 x 10(-3)) mg/g DM), whereas the concentrations detected in kidneys, liver and bone were similar to each other 1.96 x 10(-3) (SE 0.20 x 10(-3), 3.11 x 10(-3) (SE 0.24 x 10(-3), 1.77 x 10(-3) (SE 0.17 x 10(-3)) mg/g DM respectively) and 10-fold less than those detected in brain. When rats were fed on a purified diet in which InsP6 was undetectable, the InsP6 levels of the organs mentioned earlier decreased dramatically (9.0 x 10(-4), 3.8 x 10(-5), 1.4 x 10(-5) mg/g DM in brain, kidneys and liver respectively) and in some cases became undetectable (bone). The addition of InsP6 to this purified diet led to the increase of InsP6 levels in these tissues. This clearly demonstrated that the majority of the InsP6 found in organs and tissues has a dietary origin and is not a consequence of endogenous synthesis. Consequently, considering that InsP6 could be involved in some important biological roles, the value of any diet on supplying this substance is noteworthy.

Variation of InsP(4),InsP(5) and InsP(6) levels in tissues and biological fluids depending on dietary phytate.

Due to the increasing interest of InsP(6) on human health, the aim of this paper is to compare the levels of highly phosphorilated inositols (InsP(4), InsP(5) and InsP(6)) in organs and biological fluids of rats and to study the influence of the presence and absence of InsP(6) in diets. Thus, for this purpose, the variation of InsP(4), InsP(5) and InsP(6) levels in organs and biological fluids of rats submitted to two different diets were studied. In the AIN-76A diet no InsP(6) was present, yet the other was a 1% InsP(6) modified diet (AIN-76A + 1% InsP(6)). The highest InsP(4), InsP(5) and InsP(6) levels were found to be 10-fold superior in the brain than those found in the kidney. When the InsP(6) was eliminated from the diet, the InsP(6) levels decreased dramatically (97.2% in kidney, 89.8% in brain, 100% in bone, 90.5% in plasma and 98.1% in urine), the InsP(5) levels showed an important decrease (61.2% in kidney, 45.5% in brain, 28.1% in bone, 30% in plasma and 88.6% in urine) and the InsP(4) levels in organs only changed slightly. From these results, it can be deduced that the majority of InsP(6) present in the organism is of dietary origin and its endogenous synthesis is not important. According to the results, it can be evidenced that the endogenous synthesis of InsP(5) can occur, besides InsP(6) can be transformed by enzymatic dephosphorilation in InsP(5).

Dietary phytate and mineral bioavailability.

The relation between the dietary phytate (InsP6), mineral status and InsP6 levels in the organism, using three controlled diets (AIN-76A, AIN-76A + 1% phytate, AIN-76A + 6% carob seed germ), are studied. AIN-76A is a purified diet in which InsP6 is practically absent. No important or significant differences in the mineral status (Zn, Cu, Fe) of blood, kidneys, liver, brain and bone, were observed, except iron in the brain. Thus, the amounts of iron found in the brain of rats fed AIN-76A + 1% InsP6 were significantly inferior to those found in rats fed AIN-76A diet. The amounts of InsP6 found in organs of rats fed AIN-76A diet became very low or even undetectable while the ones found in rats fed diets that contained 1% and 0.12% (AIN-76A + 6% carob seed germ) InsP6, were considerably higher and similar. Moreover the majority of rats fed AIN-76A diet exhibited calcifications at the corticomedullary junctions, whereas no calcifications were detected in rats fed the other two diets. From these results, it can be deduced that there was no important adverse effects on mineral status as a consequence of the presence of InsP6 in the studied diets. Besides, considering that a 0.12% InsP6 contained in the AIN-76A purified diet through the addition of a 6% of carob seed germ to this diet, produced the same beneficial effects as the direct addition of a 1% of InsP6 and no negative effects on mineral status was observed, it can be concluded that the value of the presence of InsP6 at adequate amounts in the diet is remarkable and must be favourably considered.

Urinary phytate in calcium oxalate stone formers and healthy people--dietary effects on phytate excretion.

The phytate urinary levels in a group of active calcium oxalate stone formers were studied and compared with those found in healthy people. Urinary phytate was significantly lower for stone formers. If deficit of the capacity to inhibit crystallization of calcium salts is considered an important factor related to calcium stone formation, the excretion of low phytate amounts could be an important risk factor in the development of this type of renal calculi. The influence of dietary phytate on urinary excretion was also studied. Clearly maintenance of a phytate-free diet significantly decreased the urinary excretion of phytate (about 50% after 36 h). This demonstrated the importance of dietary phytate in maintaining adequate urinary levels to permit effective crystallization inhibition of calcium salts and consequently preventing renal stone development.