Thermal, UV, FTIR, and XRD studies of urinary stones

Various crystals are seen in human urine. Oxalate, Phosphate, Uric acid, and Urate crystals are generally seen in urinary calculi. Calcium stones are most common, comprising 75 % of all urinary calculi. They may be pure calcium oxalate or calcium phosphate or a mixture of both. Many stones are not homogeneous. Low calcium intake increases the intestinal absorption of calcium, thus decreasing the amount of calcium available in the intestinal tract to form insoluble complexes with Oxalate. Consequently, a higher amount of oxalate is available for intestinal absorption and as a result, urinary oxalate excretion increases. Mineral water consumption did not reduce urinary oxalate excretion. High urinary excretion and concentration of magnesium decrease both the nucleation and growth rates of calcium oxalate crystals in urine, because of the higher solubility of magnesium oxalate compared with calcium oxalate. Analytical results show calcium oxalate to be one of the major inorganic components of renal stones and found to be present in almost all kidney and bladder stones. About 39.5 % of the total composition of the calculi is found to contain purely calcium oxalate and also hydroxyl apatite. The ten samples are a mixture of calcium oxalate and phosphate stones. Four samples are calcium oxalate as major composition and the remaining are calcium phosphate as major composition. These kidney stones are taken photographically and size of the stone are measured using optical microscopy. These qualitative analyses are also confirmed by UV, FTIR, DSC, and XRD analysis.     

Evaluation of the renal calculi compositions

Thermal analysis and infrared (IR) spectroscopy are modern physical–chemical methods suitable for the investigation of the kidney stones composition. The applications of these methods in our work were anticipated by performing the standard thermal analysis and standard infrared spectra on pure compounds: oxalates, phosphate, carbonate, and uric acid. This work reveals a logical algorithm for correlating the experimental data regarding urolithiasis types and compositions by thermal analysis methods, Fourier Transform Infrared (FT-IR) spectroscopy, and second derivative FT-IR spectra. The limits and performance of each analysis method have been highlighted, and by correlating the results of both methods we have obtained comprehensive information for the identification and/or determination of the main components as well as of organic and/or inert impurities in calculi composition. The data regarding the urinary calculi composition are important for the clinical guideline in the prophilaxy and methaphylaxy of urolithiasis.     

Laser ablation of gall bladder stones.

Study of laser interaction with calculi is presented. A system of Nd-Yag and Ho-Yag pulsed lasers were used to produce fluorescence and plasma signals at the stone surface surrounded by saline and bile fluids. Fourth harmonic from Nd-Yag laser was transmitted to the samples by graded UV optical fibres. Gall bladder stones of various compositions were subjected to the high power Ho-Yag laser. Temporal transients and spectral evolution of plasma and fluorescence signals were monitored by a streak camera. A profile of acoustic pressures generated by shock waves was recorded with sensitive hydrophones placed in the surrounding fluids. Ablation threshold, cavitation process and fluorescence dependence on the laser parameters were studied in detail. Potential of stone identification by fluorescence and possible hydrodynamic model for ablation of biological samples is discussed.     

Differentiation of human kidney stones induced by melamine and uric acid using surface desorption atmospheric pressure chemical ionization mass spectrometry

Clinically obtained human kidney stones of different pathogenesis were dissolved in acetic acid/methanol solutions and then rapidly analyzed by surface desorption atmospheric pressure chemical ionization mass spectrometry (SDAPCI-MS) without any desalination treatment. The mass spectral fingerprints of six groups of kidney stone samples were rapidly recorded in the mass range of m/z 50-400. A set of ten melamine-induced kidney stone samples and nine uric acid derived kidney stone samples were successfully differentiated from other groups by principal component analysis of SDAPCI-MS fingerprints upon positive-ion detection mode. In contrast, the mass spectra recorded using negative-ion detection mode did not give enough information to differentiate those stone samples. The results showed that in addition to the melamine, the chemical compounds enwrapped in the melamine-induced kidney stone samples differed from other kidney stone samples, providing useful hints for studying on the formation mechanisms of melamine-induced kidney stones. This study also provides useful information on establishing a MS-based platform for rapid analysis of the melamine-induced human kidney stones at molecular levels.     

Determination of the composition of sialoliths composed of carbonate apatite and albumin using artificial neural networks

The determination of the components of the sialoliths is important both from the point of view of chances for a successful medical treatment of the patients and because the prevention of further re-occurrence of sialolithiasis depends upon the knowledge of the nature of the constituents of the concrements. Despite the fact that infrared spectroscopy is widely used for the determination of the composition of sialoliths, urinary calculi and bladder stones, we found no data for any chemometric method developed for such purposes. Here, a method is presented for quantitative determination of the content of salivary calculi composed of albumin and carbonate apatite (one of the most often found constituents in the analyzed calculi from the patients from Macedonia) using artificial neural networks (ANN). The results were checked on real samples using the standard addition method. The precision of the method was estimated using the relative standard deviation, which shows that it is suitable for routine analysis.     

A combinative technique to recognise and discriminate turquoise stone

This study attempts to identify and categorize turquoise stone based on its compounds and major factors that introduces its color change. Turquoise samples which are investigated in this study have been collected from the most important turquoise mines in world. Combination of two different analysis methods assists this study for scrutinizing turquoise constituents and effects of their percent on its color change. The application of infrared spectroscopy and X-Ray Fluorescence (XRF) methods can reveal the true composition of various “turquoise” samples in range of blue color to green color. Whereas the first technique (FTIR) is especially capable in diff ;erentiating between natural samples and fake or simulant stones for prevent of jobbery. Changing percent of four compounds including CuO, Al₂O₃, P₂O₅ and Fe₂O₃, is the most effective factors of varying color in turquoise stones. In conclusion, blue turquoise stone contains great percent of light elements or blue color factors in comparison to green turquoise stone which contains jorum of heavy element.     

Instrumental neutron activation analysis of urinary calculi

Five kinds of urinary stones from 42 patients have been determined for a total of 19 elements by instrumental neutron activation analysis. Of these elements, Ca, Mg, Sr, Na, and Cl are found to be present in the core of all kinds of stones. The differences in elemental composition among the different kinds of stones as well as across the layers of stone are statistically evaluated.     

鲁北地区人体结石的成分及成因分析

采用X射线衍射（XRD）、红外光谱（IR）和扫描电子显微技术（SEM）对鲁北地区22例手术取出的人体结石标本进行了分析。用原子吸收光谱分析（AAS）对鲁北地区饮用水中的微量元素进行了测定。结果表明鲁北地区的人体胆结石主要有胆固醇结石、胆色素结石和泥砂质结石,其中以泥砂质结石较多,未发现混合结石。该地区尿路结石中,上尿路（肾、输尿管）结石以草酸钙、尿酸结石为主,下尿路（膀胱）结石以鸟粪石（六水磷酸镁氨）、羟基磷灰石为主,未发现尿道结石。该地区的人体结石的形成与当地的环境和水质有关。     

扫描电镜对胆色素结石溶解前后的微观结构观察及元素检测

本实验用ＪＥＭ－１２００ＥＸ／Ｓ扫描电镜观察了溶解前后２０例胆色素结石的微观结构，并对所含元素作了检测和比较。结果表明：胆色素结石及其难溶组分中主要有１２种元素，钙含量最高，这说明元素钙在胆色素结石的成石过程中起了重要作用。     

Analysis of urinary stone constituents using powder X-ray diffraction and FT-IR

Constituents of urinary stones obtained from various patients from western part of India, which is a highly urinary stone disease-prone area, have been analysed. Eight stones from four patients were collected through urologists and have been analysed using powder X-ray diffraction and FT-IR. Thermogravimetric analysis (TGA) and scanning electron microscopic (SEM) image of selected samples were also carried out. The analysis revealed that calcium oxalate monohydrate, which is also known as whewellite, is the common constituent of all of the stones, particularly at the initial stage of stone formation. However, multi phases viz. whewellite phase, and hydroxyl and carbonate apatite phases are also detected in the case of third and fourth patients, from where multiple stones were obtained. Interestingly, in these mixed phase stones the concentration of whewellite decreases with increasing the concentration of apatite phases. Thermal behaviour of the whewellite phase was studied by TGA and variable temperature XRD analysis. Morphology of the whewellite and apatite phases, examined by SEM image, has also been reported.     

Thermal analysis of renal stones

The chemical composition of 200 renal stones, collected from Taxila, Rawalpindi and Islamabad regions in Pakistan, was determined by thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The thermal curves show weight losses at various temperatures indicating dehydration and decomposition phenomena of renal stones. Results were compared with qualitative data obtained by IR analysis which confirmed the chemical composition of various stones in the solid state. The thermal curves helped in the differentiation of various kinds of water held by stones and their chemical composition was obtained by weight loss during pyrolysis. It was found that 26.5% of the stones were pure whewellite, 3% weddellite, 13% uric acid anhydrous, 7.5% struvite, 2.5% ammonium acid urate, 0.5% cystine and 47% stones had mixed composition. In the mixed state the most frequent combinations were those of calcium oxalate with uric acid (14.5%) and with phosphates (27.5%).

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Zusammenfassung Mittels TG und DTA wurde die chemische Zusammensetzung von 200 Nierensteinen untersucht, die in den Gebieten Taxila, Rawalpindi und Islamabad in Indien gesammelt wurden. Die Thermogramme zeigen Masseverluste bei verschiedenen Temperaturen, die auf Dehydratation und Zersetzung der Nierensteine hinweisen. Die Ergebnisse wurden mit den qualitativen Resultaten aus der IR-Analyse verglichen, welche die chemische Zusammensetzung der verschiedenen Steine im festen Zustand bekräftigte. Die Thermogramme halfen bei der Unterscheidung von verschieden gebundenem Wasser, ihre chemische Zusammensetzung wurde durch Gewichtsverlust bei der Pyrolyse bestimmt. Man fand, daß 26.5 % der Steine aus reinem Whewellit bestanden, 3 % aus Weddellit, 13 % aus anhydrierter Harnsäure, 7.5 % aus Struvit, 2.5 % aus Ammmoniumhydrogenurat, 0.5 % aus Cystin und 47 % der Steine hatten eine gemischte Zusammensetzung. Die häufigsten Kombinationen der Mischzusammensetzungen waren Calciumoxalat mit Harnsäure (14.5 %) und mit Phosphaten (27.5 %).

     

The use of thermal analysis in determination of some urinary calculi of calcium oxalate

The human urinary calculi are mainly constituted by calcium oxalate, magnesium ammonium phosphate hexahydrate, and uric acid. The ions or molecules are easily characterized by wet chemical methods. The difficulties appear in the differentiation of the hydrates of calcium oxalate (monohydrate COM or Whewellite, and dihydrate COD or Weddelite). A high level of COD in the urinary stones leads, often, inflammation, sharp pain and blood in urine. In the worse cases, they must be extracted by surgical way. The identification of the main components of urinary calculi, the knowledge of the true number of water molecules bounded to the calcium oxalate, and the determination of each hydrate in the mixture, are the interests of this memory. The thermal analysis (simultaneous DTA-TG) was applied on thirty-three urinary calculi. The determination of the calcium oxalate hydrates was confirmed by calorimetry (DSC). This revised version was published online in July 2006 with corrections to the Cover Date.     

泌尿系统尿酸结石研究中的化学基础

尿酸结石是指尿酸及其盐在泌尿系统的异常矿化和积聚。本文从尿酸结石研究中涉及的化学问题入手,讨论了pH、过饱和度、尿大分子抑制剂和基因突变等方面对尿酸结石形成的分子机理,从抑制尿酸结石成核、生长和聚集的角度,讨论了尿酸结石的化学模型和动物实验模型。     

A New Discovery of Calcium Phosphate Urinary Stones Formation Induced by Melamine: Nanocrystalline Assembly Mechanism

Melamine (Mel), a contaminant that has received much attention in recent years, has been adulterated into milk powder, causing a large number of infants suffering from kidney stone disease. To study the process and mechanism of calcium phosphate (CaP) stone formation induced by Mel, we simulated the formation process of CaP stones and studied the effect of Mel on crystallization in aqueous and synthetic urine systems, respectively. Ion selective electrode method was used to study the thermodynamic parameters and reaction rate of the crystallization process. It was firstly discovered that Mel could induce the formation of CaP crystals significantly under weak acidic urine conditions in which CaP cannot be stably present, so it may cause people to produce CaP stones. Thermodynamic parameter and reaction rate analysis indicated that Mel could increase the reaction tendency and accelerate the formation of CaP crystals, which was achieved by two process of electrostatic adsorption and release of calcium ions. This research is expected to provide scientific guidance for the prevention and treatment of Mel‐related stones.     

草酸钙型尿结石病人结石和尿液微晶的形貌特征分析

泌尿系结石是临床上的常见病和多发病,可生长于肾盂、肾实质、输尿管以及膀胱中,较大的结石常会导致尿道阻塞、感染甚至肾脏坏死等病变,是一种严重危害人体健康的泌尿系统疾病。尿结石是动物体内异常生物矿化的产物,其主要成分有草酸钙、磷酸铵镁、尿酸等,其中以草酸钙最为常见。本研究直接取肾结石病人排出体外的自然结石和尿液中的结石微晶作为研究对象,采用透射电子显微镜、扫描电子显微镜、X-射线衍射分析和傅立叶变换红外光谱等手段对尿结石进行表征分析。研究结果表明,尿液中的纳米微晶的聚集是导致微晶快速增大和结石形成的关键因素,通过调控纳米微晶的物理化学性质有可能抑制肾结石的形成和复发。     

Role of diet and trace elements in lithogenesis of renal calculi

Twenty eight stones were characterized for chemical composition and structure. The concentrations of trace elements were determined using INAA while EDXRF was used for determining the calcium contents of the stones. Twenty stones were found to be mainly composed of calcium, six were mixed type and the remaining two were of uric acid type. The concentrations of trace elements namely Zn, Sr, Fe and Cr were lower in uric acid stones as compared to calcium based stones. Diet analysis of 310 patients who were treated for renal stones showed a diet rich in calcium and oxalate and decreased water consumption.

     

Proteomics and Detection of Uromodulin in First-time Renal Calculi Patients and Recurrent Renal Calculi Patients

Renal calculi disease or known as kidney stone disease is the most common urological disorder in both men and women, although it is more prevalent in men. The lifetime chance for an individual to develop renal calculi is ~10% whereas the risk of recurrence in a 10-year period is 74%. Therefore, a diagnostic tool for screening or detecting renal calculi is greatly needed. In this study, we analyze urinary protein profiles from patients with renal calculi for the first time (RC), healthy subjects (HS), and patients with recurrent renal calculi (RRC) to identify a biomarker for detecting the disease. Urinary proteins were isolated by salt precipitation and the proteins resolved by SDS-PAGE. Target proteins were analyzed with LC/MS/MS. Thirty-two proteins were identified from healthy subjects and patients. Uromodulin was the most abundant urinary protein in HS but was a very faint band if detected at all from those that formed renal calculi for the first time (p < 0.05). Yet the excreted levels of urinary uromodulin in RRC were similar to those of the HS suggesting that uromodulin is a reliable biomarker for only RC. In addition, a few immunoglobulins that were commonly found in the urine of both RC and RRC, which include Ig alpha heavy chain 1, Ig gamma-2 c region, Ig gamma-3 heavy chain disease protein, Ig heavy chain variable region, Ig heavy constant region gamma 4, and Ig heavy chain. Ig heavy chain Fab frag and antibody a5b7 chain B may serve as potential biomarkers for renal calculi disease.     

Urinary calculi — atypical source of information on mercury in human biomonitoring

Chemical analysis of various biological matrices is routinely used for assessment of human exposure to various toxic metals. In this work, 489 samples of urinary calculi originating from almost the whole of The Czech Republic, were collected and subjected to mineralogical and elemental analysis. This study was aimed at mercury, the content of which was determined using thermo-oxidation — cold vapor — atomic absorption spectrometry. The effects of mineralogical composition, sex, age and region were recorded in order to verify the applicability of urinary calculi for biomonitoring. Relationships with other minor and trace elements were also investigated. Association of mercury with whewellite mineral was observed as well as a remarkable relationship with selenium, confirming the role of selenium in mercury excretion. No statistically significant effect was observed on the mercury content in stones with regard to the sex or region. Median values in age groups follow a trend with the maximum median value 0.365 mg kg^?1 in the group of 41–50 year old donors, decreasing to 0.060 mg kg^?1 for the oldest group (81–92 years). Our results confirm that urinary calculi can be helpful in providing complementary information on human exposure to mercury and its excretion.

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Studying the ash behaviour of agricultural residues using thermal analysis

In this paper, the ash behaviour of some typical Mediterranean agricultural residues, such as peach stones, cotton gin wastes and grape residues is studied via simultaneous, (DTA/TG), thermal analysis methods. Furthermore, the effect of various pre-treatment techniques, such as fractionation and leaching, on the ash behaviour of the specific residues is also studied. Fractionation improves some of the main biomass properties such as calorific value, volatiles and ash content but deteriorates significantly the ash chemical composition of the remaining ash fraction. Leaching improves both the main properties of the treated biomass samples and the chemical composition of the remaining ash fraction, while the combination of the two pre-treatment methods results in a merge of their main advantages leading to an even larger improvement of the ash thermal behaviour. This revised version was published online in July 2006 with corrections to the Cover Date.