Advantage of zero-crossing-point first-derivative spectrophotometry for the quantification of calcium oxalate crystalline phases by infrared spectrophotometry

Targeting urinary calcium oxalate crystallization with inulin-type AOFOS from Aspidopterys obcordata Hemsl. for the management of rat urolithiasis

ETHNOPHARMACOLOGICAL RELEVANCE

Calcium oxalate crystals play a key role in the development and recurrence of kidney stones (also known as urolithiasis); thus, inhibiting the formation of these crystals is a central focus of urolithiasis prevention and treatment. Previously, we reported the noteworthy in vitro inhibitory effects of Aspidopterys obcordata fructo oligosaccharide (AOFOS), an active polysaccharide of the traditional Dai medicine Aspidopterys obcordata Hemsl. (commonly known as Hei Gai Guan), on the growth of calcium oxalate crystals.

AIM OF THE STUDY

To investigated the effectiveness and mechanism of AOFOS in treating kidney stones.

MATERIALS AND METHODS

A kidney stones rats model was developed, followed by examining AOFOS transport dynamics and effectiveness in live rats. Additionally, a correlation between the polysaccharide and calcium oxalate crystals was studied by combining crystallization experiments with density functional theory calculations.

RESULTS

The results showed that the polysaccharide was transported to the urinary system. Furthermore, their accumulation was inhibited by controlling their crystallization and modulating calcium ion and oxalate properties in the urine. Consequently, this approach helped effectively prevent kidney stone formation in the rats.

CONCLUSIONS

The present study emphasized the role of the polysaccharide AOFOS in modulating crystal properties and controlling crystal growth, providing valuable insights into their potential therapeutic use in managing kidney stone formation.

Sulfated Laminarin Polysaccharides Reduce the Adhesion of Nano-COM Crystals to Renal Epithelial Cells by Inhibiting Oxidative and Endoplasmic Reticulum Stress

Purpose: Adhesion between calcium oxalate crystals and renal tubular epithelial cells is a vital cause of renal stone formation; however, the drugs that inhibit crystal adhesion and the mechanism of inhibition have yet to be explored. Methods: The cell injury model was constructed using nano-COM crystals, and changes in oxidative stress levels, endoplasmic reticulum (ER) stress levels, downstream p38 MAPK protein expression, apoptosis, adhesion protein osteopontin expression, and cell-crystal adhesion were examined in the presence of Laminarin polysaccharide (DLP) and sulfated DLP (SDLP) under protected and unprotected conditions. Results: Both DLP and SDLP inhibited nano-COM damage to human kidney proximal tubular epithelial cell (HK-2), increased cell viability, decreased ROS levels, reduced the opening of mitochondrial membrane permeability transition pore, markedly reduced ER Ca2+ ion concentration and adhesion molecule OPN expression, down-regulated the expression of ER stress signature proteins including CHOP, Caspase 12, and p38 MAPK, and decreased the apoptosis rate of cells. SDLP has a better protective effect on cells than DLP. Conclusions: SDLP protects HK-2 cells from nano-COM crystal-induced apoptosis by reducing oxidative and ER stress levels and their downstream factors, thereby reducing crystal-cell adhesion interactions and the risks of kidney stone formation.

A functional MMP-9-1562C>T polymorphism, MMP-9 serum levels and nephrolithiasis risk in a southern Chinese population

Background

The role of matrix metalloproteinase 9 (MMP-9) in the pathophysiology of chronic kidney disease (CKD), which is associated with a nearly two-fold greater risk for urinary calculi compared to people without CKD, has been demonstrated. The aim of the research is to evaluate the association between MMP-9-1562C>T polymorphism, MMP-9 serum levels and nephrolithiasis risk.

Methods

A hospital-based case-control study involving 302 kidney stone patients and 408 controls without kidney stone from southern China was conducted. Sanger sequencing was used to genotype the MMP-9-1562C>T polymorphism. The serum MMP-9 was measured in 105 kidney stone patients and 77 controls by enzyme-linked immunosorbent assay.

Results

Compared to the control group, the CT genotype was more frequent in nephrolithiasis patients (adjusted OR = 1.60, 95% CI = 1.09-2.37: the risk of developing nephrolithiasis in individuals with CT genotype compared to CC genotype). Moreover, there was also a higher frequency of CT/TT genotypes among patients with nephrolithiasis (adjusted OR = 1.49, 95% CI = 1.02-2.19: the risk of developing nephrolithiasis in individuals with CT/TT genotypes compared to CC genotype). The risk remained for the subgroups of patients aged >53, smokers with pack-years of smoking >20, non-drinkers, non-diabetic patients, patients with hypertension, recurrent episodes and calcium oxalate stones (OR = 2.26, 95% CI = 1.31-3.91; OR = 5.47, 95% CI = 1.10-27.30; OR = 1.76, 95% CI = 1.14-2.72; OR = 1.54, 95% CI = 1.03-2.30; OR = 1.97, 95% CI = 1.01-3.82; OR = 1.67, 95% CI = 1.06-2.62; OR = 1.54, 95% CI = 1.02-2.32, respectively). Biochemical parameters did not differ between genotypes. Compared to controls (18.57 ± 5.80 ng/mL), nephrolithiasis patients had significantly higher serum MMP-9 levels (30.17 ± 6.78 ng/mL, p < 0.001). The serum MMP-9 levels of patients with CT/TT genotypes of MMP-9-1562C>T were significantly higher than those with CC genotype (32.00 ± 6.33 vs. 29.13 ± 6.85 ng/mL, p = 0.037).

Conclusion

The MMP-9-1562C>T polymorphism in association with its soluble protein increased the risk of kidney stone, thus suggesting it could be used as a susceptibility biomarker for nephrolithiasis. Further functional studies and larger studies that include environmental exposure data are needed to confirm the findings.

Quantitative analysis of calcium oxalate monohydrate and dihydrate for elucidating the formation mechanism of calcium oxalate kidney stones

We sought to identify and quantitatively analyze calcium oxalate (CaOx) kidney stones on the order of micrometers, with a focus on the quantitative identification of calcium oxalate monohydrate (COM) and dihydrate (COD). We performed Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), and microfocus X-ray computed tomography measurements (microfocus X-ray CT) and compared their results. An extended analysis of the FTIR spectrum focusing on the 780 cm-1 peak made it possible to achieve a reliable analysis of the COM/COD ratio. We succeeded in the quantitative analysis of COM/COD in 50-μm2 areas by applying microscopic FTIR for thin sections of kidney stones, and by applying microfocus X-ray CT system for bulk samples. The analysis results based on the PXRD measurements with micro-sampling, the microscopic FTIR analysis of thin sections, and the microfocus X-ray CT system observation of a bulk kidney stone sample showed roughly consistent results, indicating that all three methods can be used complementarily. This quantitative analysis method evaluates the detailed CaOx composition on the preserved stone surface and provides information on the stone formation processes. This information clarifies where and which crystal phase nucleates, how the crystals grow, and how the transition from the metastable phase to the stable phase proceeds. The phase transition affects the growth rate and hardness of kidney stones and thus provides crucial clues to the kidney stone formation process.

Pentoxifylline/Valsartan co-delivery in liposomal gel alters the inflammatory HMGB-1/ TLR pathway and promotes faster healing in burn wounds: A promising repurposed approach

Burn wounds are one of the most severe complex forms of trauma. Hence, new treatment strategies that facilitate the healing process; reduce the severity and the healing time is the main concern of the health care systems. In this work, pentoxifylline-valsartan, (PTX- VAL), loaded liposomes integrated into gel were designed for the first time as a novel co-delivery carrier for the treatment of burn wounds. The objective of this work was to investigate the ability of the nano-based liposomal system to co-entrap two repurposed drugs; hydrophilic pentoxifylline and lipophilic valsartan for topical treatment of burn wounds. The impact of increasing the phospholipid amount to enhance the co-entrapment of PTX and VAL was investigated and in-vitro evaluation of the prepared formulations was conducted to choose the optimum composition with the highest entrapment of both drugs adopting a simple, reliable derivative spectrophotometric method. Structure elucidation was also performed using a transmission electron microscope. In addition, A simple selected derivative spectrophotometric method was developed for the assay of PTX-VAL novel combination. The proven selectivity, precision and accuracy assured the reliability of this analytical method. Being economic and fast makes routine application of the developed analytical method is recommended in pharmaceutical industry. The selected liposomal formulation integrated into gel matrix (PTX-VAL-LG) showed; nanometric size, acceptable entrapment efficiency of both PTX and VAL as well as sustained release profiles and thus, enhanced action.

Implementation of a Technique Based on Hounsfield Units and Hounsfield Density to Determine Kidney Stone Composition

Hounsfield units (HU) are a measure of radiodensity, related to the density of a tissue and the composition of kidney stones. Hounsfield density is what is related to the composition of kidney stones. In the standard acquisition method, these measures are arbitrary and dependent on the operator. This study describes the implementation of a technique based on the HU and Hounsfield density to predict the stone compositions of patients with nephrolithiasis. By conventional percutaneous nephrolithotomy, thirty kidney stone samples corresponding to the cortex, middle, and nucleus were obtained. The HU were obtained by CT scanning with a systematic grid. Hounsfield density was calculated as the HU value divided by the stone’s greatest diameter (HU/mm). With that method and after analyzing the samples by IR-spectroscopy, anhydrous uric acid and ammonium magnesium phosphate were identified as the compounds of kidney stones. Additionally, anhydrous uric acid, magnesium ammonium phosphate, and calcium oxalate monohydrate were identified via Hounsfield density calculation. The study identified HU ranges for stone compounds using a systematic technique that avoids bias in its analysis. In addition, this work could contribute to the timely diagnosis and development of personalized therapies for patients with this pathology.

Biochemical Alterations in Patients with Oxalocalcic Lithiasis, the Influence of Sex, Age, and Body Mass Index

Background: Urolithiasis is a disorder that has a high prevalence in the population. Also, lithiasic patients have biochemical alterations that predispose them to the formation of stones. The knowledge of these alterations may be useful for future preventive interventions. Objectives: The objectives were to describe the metabolic characteristics of patients with oxalocalcic lithiasis, identifying the most frequent biochemical alterations, and their variation with different demographic variables. In this way, we can prevent the formation of the lithiasis before it appears, instead of treating it once established. Methods: A descriptive cross-sectional study of serum and 24 hour-urine parameters in patients with oxalocalcic lithiasis was performed. The most frequent biochemical alterations were described, and their association with age, sex, and body mass index (BMI) were assessed. Results: In this study, 100% of the 151 patients had biochemical alterations, the most frequent being hypocitraturia (84.7%), hypercalciuria (51.7%), and urinary pH decrease (44.4%). There were differences according to sex, age, and BMI with regard to the biochemical alterations. Hypouricemia, hypouricosuria, hypophosphaturia and hypomagnesuria were more frequent in women. Men had a higher percentage of hyperzinquemia, hyperphosphaturia, and excess of urinary urea. Urine density in men was slightly higher than in women. A higher percentage of hyperphosphaturia, excess urinary urea, and excess of serum urea was found in overweight patients. Patients not overweight showed a higher percentage of hypouricemia and hypomagnesuria. Urinary density was slightly higher in overweight patients. Urinary volume was higher in middle-aged subjects. Conclusions: Patients with oxalocalcic lithiasis have biochemical alterations that may predispose to stone formation. These alterations vary with sex, age, and BMI.

Cadmium immobilization in aqueous solution by Aspergillus niger and geological fluorapatite

This study investigated the application of fungus Aspergillus niger and geological fluorapatite (FAp) to cadmium (Cd) immobilization in aqueous solution. The initial Cd concentrations were set at 100, 50, 25, and 10 mg L^-1. The mineralogy of the products was investigated by using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and attenuated total reflection-infrared spectroscopy (ATR-IR). In both A. niger + FAp + Cd and A. niger + Cd treatments, A. niger secreted abundant oxalic acid, then dissolved the FAp, and reacted with Cd²⁺ cations to produce relatively insoluble Cd oxalate. Meanwhile, FAp can provide P source to improve microbial growth. The fungal tolerance to Cd²⁺ was identified at around 100 mg L^-1. The final Cd concentrations of 13.7, 3.2, and 0.2 mg L^-1 were recorded for A. niger + FAp + Cd treatments with initial Cd concentrations of 50, 25, and 10 mg L^-1 respectively. Meanwhile, it was observed that the Cd concentration at 25 mg L^-1 stimulated higher bioactivities of A. niger, which further enhanced Cd bioremediation. The immobilization efficiency (%) of the treatments at low to medium Cd concentrations was in the order: Asp + FAp > Asp > FAp, while FAp alone was most efficient at the high Cd concentration of 100 mg L^-1. This research provides insights into the mechanisms of combining fungus and FAp as a composite to Cd contamination at various Cd levels.

Mineralogical, compositional and isotope characterization of human kidney stones (urolithiasis) in a Sri Lankan population

In order to understand the processes of stone formation, compositional, spectroscopic, mineralogical and crystallographic characteristics of human urinary stones collected from patients in Sri Lanka were investigated in detail. The data showed that the majority of urinary calculi were calcium oxalate, either whewellite or weddellite. Other solid phases of stones were composed of struvite, uricite and hydroxylapatite. However, mixed compositions were common except for whewellite stones which occur frequently in pure form. Scanning electron microscope observations and associated energy-dispersive X-ray analyses revealed that whewellite or weddellite was well crystalized compared to other stones types, while phosphate stones were mostly cryptocrystalline. The average δ¹³C and δ¹⁸O of stones were - 32.2‰ (- 37.3 to - 17.4‰) and - 24.2‰ (- 26.7‰ to - 8.9‰), respectively. The δ¹³C values were highly depleted compared to North American and European urinary stones. This may be due to food habits of Asians who consume rice as the staple food.

Idiopathic calcium nephrolithiasis with pure calcium oxalate composition: clinical correlates of the calcium oxalate dihydrate/monohydrate (COD/COM) stone ratio

Pure calcium oxalate is the most frequent type of idiopathic kidney stone composition. Fourier transform infrared spectroscopy (FT-IR) allows to detect the ratio of calcium oxalate dihydrate (COD) and monohydrate (COM) crystals in stones, but the clinical significance of this parameter remains uncertain. The objective of this observational study was to verify the association of clinical and laboratory parameters of kidney stone disease with COD/COM ratio in a group of 465 (322 M, age 46 ± 14) patients suffering from idiopathic calcium nephrolithiasis with pure calcium oxalate stones (≥ 97%). Each participant underwent a complete clinical examination, serum chemistry, 24-h urine collection for the determination of the profile of lithogenic risk, and had stones analyzed by FT-IR. Most (62%) of the stones had a COD/COM ratio ≤ 0.25, and the urine chemistry of the corresponding patients showed a low prevalence of urinary metabolic abnormalities. With increasing COD/COM ratio intervals (0-0.25, 0.26-0.50, 0.51-0.75, 0.76-1), a significant association was observed for the number of urological procedures, serum calcium, 24-h urinary calcium excretion, prevalence of hypercalciuria and relative calcium oxalate supersaturation, and a negative trend was detected for the age of the first stone episode (all p values < 0.05). A linear regression model showed that the only parameters significantly associated with COD/COM ratio were 24-h urinary calcium excretion (standardized β = 0.464, p < 0.001) and urine pH (standardized β = 0.103, p = 0.013). In pure calcium oxalate idiopathic stones, COD/COM ratio may reflect the presence of urinary metabolic risk factors, and represent a guide for the prescription of urinary analyses.

Shape and structure controlling of calcium oxalate crystals by a combination of additives in the process of biomineralization

The origin of complex hierarchical superstructures of biomaterials and their unique self-assembly mechanisms of formation are important in biological systems and have attracted considerable attention. In the present study, we investigated the morphological changes of calcium oxalate (CaO x ) crystals induced by additives including chiral aspartic acid, sodium citrate, Mg2+, casein and combinations of these molecules. The morphology and structure of CaO x were identified with the use of various techniques. The morphogenesis of CaO x crystals were significantly affected by chiral aspartic acid, sodium citrate or Mg2+. However, they only formed calcium oxalate monohydrate (COM). It was observed that the chiral aspartic acid, sodium citrate and casein adhered to the surface of the crystals. The adherence of Mg2+ to crystals was not evident. Casein significantly affected the formation of COM and calcium oxalate dihydrate (COD). The ratio of different CaO x crystal forms is associated with the casein concentration. In combination with Mg2+ or citrate ions, casein showed improved formation of COD. The present study mimics biomineralization with a simple chemical approach and provides insight into the complicated system of CaO x biomineralization as well as facilitates the understanding of urinary stone treatment.

The influence of maternal and paternal history on stone composition and clinical course of calcium nephrolithiasis in subjects aged between 15 and 25

Our aim was to compare the influence of maternal history of stones (MHS) and paternal history of stones (PHS) on composition of calculi and disease course in a group of patients with calcium nephrolithiasis (CN) aged between 15 and 25, the age range with the maximal influence of family history on disease expression. One-hundred thirty-five patients (68 F) with CN and one stone-forming parent were retrospectively selected from the database of our outpatient stone clinic, and categorized according to MHS or PHS. Data about stone disease course and composition of passed calculi, determined by chemical analysis or Fourier-transformed infrared spectrophotometry, were collected together with information on blood chemistry and 24-h urinary profile of lithogenic risk. The characteristics of disease course and stone composition were compared using logistic regression tests adjusted for age, sex, and BMI or analysis of covariance where appropriate. Patients with MHS (n = 46) had significantly higher urinary calcium/creatinine ratio and ammonium, a higher prevalence of urological treatments (57 vs 27 %, p < 0.001) and mixed calcium oxalate/calcium phosphate stone composition (69 vs 35 %, p = 0.002) than those with PHS. At multivariate logistic regression models, MHS was independently associated with urological treatments (OR 4.5, 95 %CI 1.9-10.7, p < 0.001) and the formation of calculi with mixed calcium oxalate/calcium phosphate composition (OR 5.8, 95 %CI 1.9-17.9, p = 0.002). The method of stone analysis did not affect this result. In conclusion, in subjects aged 15-25, MHS is associated with mixed calcium stones and with a higher risk for urological procedures, and should be, therefore, considered in the management of urolithiasis.

Oxalate secretion by ectomycorrhizal Paxillus involutus is mineral-specific and controls calcium weathering from minerals

Trees and their associated rhizosphere organisms play a major role in mineral weathering driving calcium fluxes from the continents to the oceans that ultimately control long-term atmospheric CO2 and climate through the geochemical carbon cycle. Photosynthate allocation to tree roots and their mycorrhizal fungi is hypothesized to fuel the active secretion of protons and organic chelators that enhance calcium dissolution at fungal-mineral interfaces. This was tested using (14)CO2 supplied to shoots of Pinus sylvestris ectomycorrhizal with the widespread fungus Paxillus involutus in monoxenic microcosms, revealing preferential allocation by the fungus of plant photoassimilate to weather grains of limestone and silicates each with a combined calcium and magnesium content of over 10 wt.%. Hyphae had acidic surfaces and linear accumulation of weathered calcium with secreted oxalate, increasing significantly in sequence: quartz, granite < basalt, olivine, limestone < gabbro. These findings confirmed the role of mineral-specific oxalate exudation in ectomycorrhizal weathering to dissolve calcium bearing minerals, thus contributing to the geochemical carbon cycle.

Stabilization of submicron calcium oxalate suspension by chondroitin sulfate C may be an efficient protection from stone formation

The influences of chondroitin sulfate C (C6S) on size, aggregation, sedimentation, and Zeta potential of sub-micron calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) crystallites with mean sizes of about 330 nm were investigated using an X-ray diffractometer, nanoparticle size Zeta potential analyzer, ultraviolet spectrophotometer, and scanning electron microscope, after which the results were compared with those of micron-grade crystals. C6S inhibited the conversion of COD to COM and the aggregation of COM and COD crystallitesis; it also decreased their sedimentation rate, thus increasing their stability in aqueous solution. The smaller the size of the COD crystallites, the easier they can be converted to COM. The stability of sub-micron COD was worse than that of micron-grade crystals. C6S can inhibit the formation of calcium oxalate stones.

Inhibition on calcium oxalate crystallization and repair on injured renal epithelial cells of degraded soybean polysaccharide

This paper investigated the inhibitory effect of degraded soybean polysaccharide (DPS) on the growth of calcium oxalate (CaOxa) crystals. The results were compared with that of soybean polysaccharide without degradation (SPS). The data showed that DPS exhibited a much higher efficiency to inhibit CaOxa growth and stabilize calcium oxalate dihydrate (COD) compared with SPS. As DPS concentration increased, the soluble Ca(2+) ions significantly increased, the aggregation degree of calcium oxalate monohydrate (COM) crystals decreased, the shape of COD crystals became round and blunt, and the Zeta potential on CaOxa crystal surface reduced. The above results were all conducive for the inhibition of CaOxa crystallization. In addition, DPS displayed a distinct repairing effect on oxidative injured renal epithelial cells in African green monkey (Vero), with enhanced cell viability and extracellular superoxide dismutase activity after repair. The morphologies of the repaired cells and their regulatory capability on CaOxa growth were between the control and injured cells. The results indicated that the risk of stone formation can be reduced by DPS, and that DPS may be a potential green drug to prevent the formation of CaOxa stones.

FT-IR spectral studies on certain human urinary stones in the patients of rural area

Fourier transform infrared spectroscopy (FT-IR) has been carried out to analyze the organic and inorganic constituent of human urinary stones. Patient's hailing from Rajah Muthiah Medical College and Hospital, Annamalai University, Tamil Nadu, India was selected for the study. The FT-IR results indicate that stones have different composition, i.e., namely calcium oxalate, calcium phosphate, carbonate apatite and magnesium ammonium phosphate and uric acid. From the spectral and powder X-ray diffraction pattern, the chemical constituents of urinary stones were identified. The quantitative estimations of calcium oxalate monohydrate (COM) 1,620 cm(-1), calcium phosphate (apatite) 1,037 cm(-1), magnesium ammonium phosphate (struvite) 1,010 cm(-1), calcium carbonate 1,460 cm(-1) and uric acid 1,441 cm(-1) were calculated using particular peaks of FT-IR studies. The study reveals that calcium oxalate monohydrate and calcium phosphate type urinary stones were predominant whereas magnesium ammonium phosphate are in moderate level, and calcium carbonate and uric acid are in low. Calcium phosphate is found in all the stones and calcium oxalate monohydrate is found to be higher. Quantitative analyses of urinary stones show that calcium oxalate monohydrate (40%), apatite (30%), magnesium ammonium phosphate (23%) and uric acid (7%) are present in all the urinary stone samples.

Development of a method for the quantitative analysis of urinary stones, formed by a mixture of two components, using infrared spectroscopy

OBJECTIVES

The analysis of urinary stones is used for the diagnosis of the etiology of an episode of nephrolithiasis. The technique considered as standard for this purpose is infrared spectroscopy (IR). However, when the urinary stone is formed by a mixture of components, only semi-quantitative information can be achieved using IR. The objective of this work is the development of a quantitative method.

DESIGN AND METHODS

Bands in the IR spectra of several mixtures were studied, in order to design a calibration model useful to determine the quantitative composition of the urinary stones. For mixtures of two components, four mathematical models were proposed. To assess the validity of these models, nine series of mixtures of two components were prepared, using the most frequently compounds found in urinary stones, for analyzing by ATR-FTIR spectroscopy (Attenuated Total Reflection Fourier Transformed Infrared).

RESULTS

Nine series of nine mixtures of two components were prepared for this work. The IR spectrum was recorded for each mixture and the absorbance intensities at selected wave numbers were used to apply the proposed mathematical models. There were good linear correlations between the analytical signals (IR absorbances) and the analytical responses (weight fractions) using the calibration lines. The validity of the method was checked by the comparison between the weight fractions resulted from the calibration lines and the real weight fractions obtained by weighing, presenting good correlation parameters.

CONCLUSIONS

The method developed in this work has been useful for the quantification of compounds which are commonly found in urinary stones. This method allows a total characterization of the urinary stones (qualitative and quantitative) by means of IR spectroscopy.

Crystalline ultrastructures, inflammatory elements, and neoangiogenesis are present in inconspicuous aortic valve tissue

Morbidity from calcific aortic valve disease (CAVD) is increasing. Recent studies suggest early reversible changes involving inflammation and neoangiogenesis. We hypothesized that microcalcifications, chemokines, and growth factors are present in unaffected regions of calcific aortic valves. We studied aortic valves from 4 patients with CAVD and from 1 control, using immunohistochemistry, scanning electron microscopy, and infrared spectrography. We revealed clusters of capillary neovessels in calcified (ECC), to a lesser extent in noncalcified (ECN) areas. Endothelial cells proved constant expression of SDF-1 in ECC, ECN, and endothelial cells from valvular surface (ECS). Its receptor CXCR4 was expressed in ECC. IL-6 expression correlated with CXCR4 staining and presence of lymphocytes. VEGF was expressed by ECS, its receptor by ECC and ECN. Crystalline ultrastructures were found on the surface of histologically noncalcified areas (HNCAs), spectrography revealed calcium hydroxylapatite. Our results demonstrate that crystalline ultrastructures are present in HNCAs, undergoing neoangiogenesis in an inflammatory context. These alterations could be an early witness of disease and an opening to therapy.

Attenuated total internal reflection Fourier transform infrared spectroscopy: a quantitative approach for kidney stone analysis

The impact of kidney stone disease is significant worldwide, yet methods for quantifying stone components remain limited. A new approach requiring minimal sample preparation for the quantitative analysis of kidney stone components has been investigated utilizing attenuated total internal reflection Fourier transform infrared spectroscopy (ATR-FT-IR). Calcium oxalate monohydrate (COM) and hydroxylapatite (HAP), two of the most common constituents of urinary stones, were used for quantitative analysis. Calibration curves were constructed using integrated band intensities of four infrared absorptions versus concentration (weight %). The correlation coefficients of the calibration curves range from 0.997 to 0.93. The limits of detection range from 0.07 +/- 0.02% COM/HAP where COM is the analyte and HAP is the matrix, to 0.26 +/- 0.07% HAP/COM where HAP is the analyte and COM is the matrix. This study shows that linear calibration curves can be generated for the quantitative analysis of stone mixtures provided the system is well understood especially with respect to particle size.

Controlled growth of calcium oxalate crystal in bicontinuous microemulsions containing amino acids

The growth of calcium oxalate (CaC(2)O(4)) crystal in water channels of three kinds of bicontinuous microemulsions, consisted of P-octyl polyethylene glycol phenylether (OP)/n-amyl alcohol/cyclohexane/water and above microemulsions containing tryptophan (Trp) or aspartic acid (Asp) has been studied. The products were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The results indicated that both surfactant and amino acids all could prompt the growth of calcium oxalate monohydrate (COM) crystal, but the crystal morphology varied with the different microemulsions, pH values of the aqueous solution in channels and concentrations of the reactants. Various crystal morphologies such as butterfly-like, hollow and spiny spherical could be observed easily. A model of molecular identification--organized assembly--pervasion-combination balance was proposed to explain the formation mechanism of CaC(2)O(4) crystals in the microemulsions containing Asp.

Effects of amino acids on crystal growth of CaC2O4 in reverse microemulsion

Crystal growth of calcium oxalate (CaC2O4) in bulk aqueous solution, reverse microemulsion of p-octyl polyethylene glycol phenylether (OP)/iso-octyl alcohol (IOA)/cydohexane/water and above microemulsions containing different kinds of amino acids, such as aspartic acid (Asp), tyrosine (Tyr) and tryptophan (Trp) were studied. The results indicated that different crystallization types of the crystals, which were calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD) and calcium oxalate trihydrate (COT), existed in bulk aqueous solution. But CaC2O4 growth mainly paralleled with (1 01) plane of COM in reverse microemulsion because of the induction of surfactant at water/oil interface. After adding amino acids into microemulsions, the growth of CaC2O4 crystals mainly influenced by the varieties of amino acids and the pH values of the amino acid aqueous solution. When pH values of the solutions was higher than isoelectric points of amino acids, CaC2O4 crystal paralleled with (1 01) plane of COM more easily with the addition of Trp, Tyr, Asp in turn; however, when pH of the solutions was lower than isoelectric points of Trp, CaC2O4 crystal growth paralleled with (020) face of COM. It is obviously that amino acids, pH values of the solutions and surfactant played important roles in the process of crystal growth of CaC2O4 in the microemulsions. The formation mechanism of CaC2O4 was also discussed in different microemulsions at last.