草酸钙结石患者尿液中纳米级和微米级晶体研究

尿液中存在的微晶与尿石症的形成密切相关。采用X射线粉末衍射(XRD)、傅里叶变换红外光谱(FTIR)、纳米粒度仪、扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究了20位草酸钙结石患者尿液中纳米级和微米级晶体的组分、形貌和Zeta电位,并与结石组分进行了比较。结果表明,草酸钙结石中常常含有少量共生的尿酸、磷酸钙和磷酸铵镁;而草酸钙结石患者的尿微晶组分主要为尿酸、磷酸盐和草酸钙等,晶体棱角尖锐,尺寸不一,从几十纳米到几十微米不等,并且有明显的团聚现象。20位草酸钙结石患者的尿纳米晶体的Zeta电位平均值为-5.92 mV,明显高于20位健康对照者尿纳米晶体的Zeta电位(平均值-12.9 mV);相比之下,结石患者尿液pH值(平均值为6.03)则与健康对照者(平均值5.92)没有明显差异。利用现代仪器分析方法分析尿液微晶与尿石组分的关系,可为临床上对症下药,制定预防与治疗措施提供重要的依据。     

尿液pH变化与尿液中纳米微晶组分的关系

采用X射线衍射(XRD)和傅里叶变换红外光谱(FTIR)研究了尿液pH变化与尿液中纳米微晶组分的关系。不但尿pH差异大的不同人尿液中微晶组分存在差异,而且同一人的尿pH发生变化时,其尿微晶亦发生变化。尿pH值较低(如pH＜5.8)时,主要为尿酸、酸式磷酸盐和草酸钙等;尿pH值较高(如pH＞6.2)时,主要为尿酸盐、磷酸盐、磷酸铵镁和草酸钙等。联合运用XRD和FTIR两种方法,可以更好地检测尿液中晶体组分,有助于了解尿石症的成因。     

尿酸结石患者尿液中的微晶组分及其与结石形成的关系

采用X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱、纳米粒度仪、扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究了10例尿酸结石患者尿微晶的组分、Zeta电位、形貌及其与尿酸结石形成的关系.结果表明,尿酸结石患者的尿pH值较低,大都在4.8～5.7之间;尿微晶的主要成分为尿酸.其粒度分布很不均匀,从几纳米到几十微米不等,并有聚集现象.相比健康对照者尿纳米微品的Zeta电位(-10.1mV),尿酸结石患者的Zeta电位负值更小(-6.02 mV).对这些患者进行药物治疗(服用柠檬酸钾)后,尿pH可上升到6.5左右,此时尿液中的大部分尿酸转变为溶解度显著增加的尿酸盐,因此,尿酸结石形成的危险性显著降低.本文结果表明,尿石组分、尿微晶组分及尿pH三者之间存在密切的联系.     

服药前后草酸钙结石患者尿微晶的性质变化

采用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、纳米粒度仪和透射电子显微镜(TEM)研究了6例草酸钙结石患者在服药前后尿微晶性质的变化.结果表明,服药后尿pH值由服药前的5.87±0.51增加至6.23±0.74;服药前的主要成分为尿酸、一水草酸钙(COM)和磷酸氢盐,服药后尿微晶种类和数量均比服药前减少;服药前,尿微晶的平均粒径为(579±326) nm,服药后减小至(404±338) nm;服药前尿微晶的Zeta电位为(-4.28±2.55) mV,服药后为(-7.29±4.16) mV,Zeta电位变负有利于防止尿微晶沉积;服药前尿微品棱角尖锐,有明显的团聚现象,而服药后尿微晶形貌圆钝,团聚较少.采用现代仪器分析研究服药前后草酸钙结石患者尿液微晶的性质变化,对临床上预防和治疗尿结石具有重要的临床意义.     

磷酸铵镁结石患者尿微晶组分分析及其与结石形成的关系

采用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、纳米粒度仪、扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究了磷酸铵镁结石患者尿液中微晶的组分、形貌、粒径和Zeta电位,并对其结石进行了组分分析.结果表明,结石类型、尿微晶组分和尿液pH三者之间存在密切的联系:磷酸铵镁结石病人的尿液pH值较高,通常在6....     

不同分子量龙须菜多糖对草酸钙结晶的调控作用

植物多糖的化学结构与尿液中的结石抑制剂葡胺聚糖相似,有可能用于预防和治疗肾结石。天然多糖由于分子量和分子体积过大,导致其应用受到限制。研究了四种分子量分别为49.6,16.2,8.2和3.8 kDa的降解龙须菜多糖GLP1,GLP2,GLP3和GLP4对草酸钙(CaOx)晶体生长的调控作用。1H NMR,13C NMR和气相色谱-质谱(GC-MS)谱分析表明四种GLPs由β-D-半乳糖和6-O-硫酸基-3,6-α-L-吡喃半乳糖组成。X射线衍射(XRD)检测表明,在各GLPs存在下,诱导了二水草酸钙(COD)晶体形成,COD的衍射峰出现在晶面间距d=0.617,0.441,0.277和0.224 nm处;而没有多糖存在时只生成一水草酸钙(COM)晶体,COM的衍射峰出现在d=0.593,0.364,0.296和0.235 nm。由于COD比COM更容易排出体外,COD的形成有利于降低结石形成的风险。傅里叶变换红外光谱(FTIR)检测表明,随着GLP分子量减小或GLP浓度增加,草酸根中羧基的不对称伸缩振动ν_as(COO-)和对称对称伸缩振动ν_s(COO-)都发生了不同程度的蓝移,其中ν_as(COO-)从1 618 cm-1增加到1 642 cm-1,ν_s(COO-)从1 318 cm-1增加到1 328 cm-1,即GLP4诱导的全部是COD晶体。扫描电子显微镜(SEM)检测表明,随着GLP分子量减小,不但晶体中COD的比例增加,而且晶体的分散程度增大,晶体更加圆钝。随着GLP分子量减小或GLP浓度增加,其诱导生成的CaOx晶体表面电荷越负,Zeta电位绝对值越大,这有利于抑制晶体的聚集。电感耦合等离子体发射光谱仪(ICP)检测表明,四种GLPs均可以增加溶液中可溶性Ca2+的浓度,同时减少CaOx沉淀的生成量。在浓度为1.0 g·L-1多糖存在时,上清液中可溶性Ca2+的摩尔浓度分别为：GLP4 (37.88 μmol·L-1)>GLP3 (19.70 μmol·L-1)>GLP2 (16.05 μmol·L-1)>GLP1 (10.55 μmol·L-1)。结果表明,四种GLPs均可以抑制COM生长,诱导COD生成,降低晶体的聚集程度,增加晶体表面的Zeta电位绝对值和溶液中可溶性Ca2+浓度,减少CaOx晶体的生成量,且GLPs的调控活性与其分子量呈负相关。这些结果提示GLPs特别是分子量最小的GLP4有可能是防治CaOx结石的潜在药物。     

红外光谱法在草酸钙结石研究中的应用

泌尿系结石是一种世界范围的常见病。草酸钙是泌尿系结石中最常见的组分 ,尿石中的草酸钙主要是以一水草酸钙 (COM)、二水草酸钙 (COD)的形式存在。区分草酸钙结石中的COM和COD及其比例 ,对于准确诊断结石的成因和提出正确的预防其复发的方法非常重要。红外光谱法是研究泌尿系结石的一种较理想的常用方法 ,具有快速、简便、鉴定成分准确、使用样品少、可以回收等优点。文中重点综述了傅里叶变换红外光谱 (FTIR)在泌尿系结石研究中对COM和COD的定性和定量分析方法 ,并介绍了零交叉点一次导数光谱法、FTIR与四极质谱仪、FTIR与傅里叶变换拉曼光谱仪 (FTRS)联合分析尿石的方法。     

混合型尿路结石的XPS和XRD联合分析

为了深入了解广东省珠江三角洲尿路结石的组份,为临床的相关研究和预防提供参考,采用X-射线光电子能谱(XPS)和X-射线衍射法(XRD)对6例典型的混合型尿路结石成份和物相进行了分析。结果表明,所检尿石成份合一水草酸钙、二水草酸钙、羟基磷灰石,其中2例含有少量磷酸铵镁。随着尿石中磷酸盐的增加,一水草酸钙(COM)的含量减少,二水草酸钙(COD)含量增加,表明磷酸盐的沉积抑制了高能量的COD向低能量的COM转化。采用XPS和XRD联合分析,可以较为准确地检测尿路结石的组份和物相。     

海带多糖对草酸钙结晶过程中晶相的影响

采用X射线衍射(XRD)、红外光谱(FTIR)、扫描电子显微镜(SEM)和原子吸收光谱(AAS)等方法研究了从海带中提取的硫酸多糖(SPS)对尿结石主要成分草酸钙结晶的影响。SPS可以稳定热力学亚稳定的二水草酸钙(COD)晶体。随着SPS浓度从0增加到0.60 mg·mL-1,COD晶体的质量百分比从0增加到100％;亚稳溶液中草酸钙的相对过饱和度从1.0增加到19.6。SPS可以稳定COD晶体在溶液中的存在并增加可溶性Ca2+离子的浓度,这有利于防止草酸钙结石形成。结果表明,SPS是一种潜在的防止草酸钙尿结石形成的药物。     

三聚氰胺结石与疑似三聚氰胺结石的红外光谱分析

本文通过对三聚氰胺、尿酸、三聚氰胺结石和疑似三聚氰胺结石的红外光谱分析, 根据它们的特征峰位、峰形的特点和三聚氰胺、尿酸、草酸钙的标准红外光谱比较, 推出三聚氰胺结石由尿酸、尿酸胺、草酸钙和三聚氰胺形成的混合性结石。疑似三聚氰胺结石是草酸钙结石。因此, 红外光谱法可作为一种辅助手段, 为医学诊断提供理论依据。     

The effect of oral administration of calcium and magnesium on intestinal oxalate absorption in humans

Calcium oxalate (CaOx) urolithiasis is the most common urinary stone disease (70-75 % of all stones consist of CaOx in countries with western diet). Oxalate is the most lithogenic substance in CaOx crystallisation in urine. Oxalate is either synthesized within the body or absorbed from food. As oxalate is not metabolized in the human body, it appears unchanged in urine. Conventional analysis methods cannot distinguish between endogenous and exogenous oxalate. Our [13C2]oxalate absorption test enabled measurement of intestinal oxalate absorption and quantification of the influence of Ca- and Mg-supplementation on it. The effects of the oral administration of these supplements were compared in order to obtain valid data for recommendations for CaOx urolithiasis patients. A 10 mmol supplement of both ions decreased the oxalate absorption significantly, calcium being more than twice as effective.     

Harnessing Calcium‐Oxalate‐ (CaOx‐) Nanocrystal‐Induced Prodeath Autophagy for Attenuating Human Renal Proximal Tubular Epithelial Cell Injury

Calcium oxalate (CaOx) stone is the most common type of kidney stone, with a formation process comprising supersaturation, nucleation, growth, aggregation to crystals, and adhesion on renal tubular epithelial cells. CaOx stones generally lead to renal injury; however, the underlying mechanism remains poorly understood. Accumulating evidence suggests that nanosized materials could induce much greater toxicity than bulk materials with the same components. As aggregation to nanocrystals is necessary to form CaOx stones and nanocrystals have been widely reported to elicit either prodeath or prosurvival autophagy, the aim is to address the precise role of autophagy in CaOx‐ nanocrystal‐induced cytotoxicity. Clinical CaOx stones from patients are collected followed by ball milling. As a result, CaOx nanocrystals significantly reduce renal cell viability in a dose‐ and time‐dependent manner. Further study shows that CaOx nanocrystals possess an autophagy‐inducing capacity and autophagic flux is complete. Autophagy abrogation by specific chemical inhibitor wortmannin or chloroquine obviously attenuates cytotoxicity, strongly suggesting that prodeath autophagy contributes to CaOx nanocrystals‐elicited cytotoxicity. Finally, it is revealed that autophagy is an essential signaling pathway participating in apoptosis regulation. Collectively, the findings demonstrate the role of autophagy in CaOx‐nanocrystal‐elicited cytotoxicity, and harnessing autophagy can be helpful to design promising strategies for attenuating kidney injury in nephrolithiasis.     

Micro‐Raman spectroscopy identification of urinary stone composition from ureteroscopic lithotripsy urine powder

Urolithiasis is a prevalent, disturbing, and highly recurrent disease. Knowing the composition of a urinary stone is important for prevention purposes. Traditional urinary stone analysis methods need large stone fragments for analysis. However, the advancement of ureteroscopic lithotripsy (URSL) has resulted in micro‐stone fragments and unapparently expelled urinary stone powder. In this study, we developed a micro‐Raman spectroscopy (MRS) based diagnosis method for detecting micro‐stones or stone powders in urine after URSL. In our experiment, urine samples of 10 ml each were collected from 12 patients over the fragmented stone site in the ureter after the URSL procedure. The post‐URSL urine sediments extracted from urine were analyzed by MRS. The small urinary stones caught by grasping forceps were analyzed by both MRS and Fourier‐transform infrared (FTIR) spectroscopy. We have identified common urinary stone compositions: calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), dicalcium phosphate dihydrate (DCPD), calcium phosphate hydroxide (hydroxyl apatite or HAP), and uric acid, by using a 632.8 nm He‐Ne laser for excitation, a 100× microscope objective lens for irradiation and collection, and a short photobleaching time for fluorescent background reduction. Thus, we developed an MRS‐based method for analyzing the composition of urinary stone powders directly from the urine samples after the URSL procedure. This approach provides a quick and convenient method for urinary stone analysis. Copyright © 2009 John Wiley & Sons, Ltd.     

不同类型尿石的XRD,FTIR和热释光谱分析

采用热释光谱仪(TLD)、X射线衍射仪(XRD)和红外光谱仪(FTIR)研究了四类不同类型肾结石的化学组分,它们分别是:草酸钙、尿酸、磷酸钙和磷酸铵镁结石.实验结果表明,在所研究的305例尿石中,草酸钙为主要组分的占63%,尿酸22%,磷酸钙8%,磷酸铵镁5%,其他组分2%.四类肾结石的热释光谱存在显著差异,可为临床上诊断肾结石的类型提供启示.     

二元羧酸的化学结构与其抑制草酸钙结晶能力研究

采用X射线衍射(XRD)、傅里叶红外光谱(FTIR)和扫描电镜(SEM)研究了相距3个C—C键长具有不同取代基的二元羧酸对草酸钙(CaOxa)晶体生长的影响。这些二元酸包括丁二酸、顺丁二烯酸、反丁二烯酸、苹果酸、天冬氨酸和酒石酸。它们均能抑制一水草酸钙(COM)晶体的聚集,减小COM比表面积,并诱导二水草酸钙(COD)生成,其能力随二元酸上取代的—OH或—NH₂基数量增加而增强。从二元羧酸化学结构讨论了其影响草酸钙结晶效果的分子机理,对COM生长具有最佳抑制效果的羧酸是含有HOOC—CH(R)—CH₂—COOH(ROH或NH₂)分子的化合物。实验结果可为临床上寻找新的防石药物提供参考。     

EDXRF,FTIR, and XRD characterization of low calcium oxalate urinary stones collected from arid area

Low calcium oxalate urinary stones from the kidney, bladder, and ureter have been collected from the arid area (Taif, Saudi Arabia). After careful washing and drying of the collected stones, the samples were converted into a contamination-free homogenous fine powder with a particles' size smaller than 50 μm. The processed urinary stone powders were studied using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), laboratory setup and synchrotron radiation X-ray diffraction (XRD), and energy-dispersive X-ray fluorescence (EDXRF). The activated function groups, quantitative phase analysis, and the semi-quantitative elemental analysis of the present urinary stones were identified. Seventeen elements were measured in most of the urinary stone samples. The significant elements are Ca, P, S, Cl, Zn, K, Fe, and Cu, whereas other elements were found alternatively in a few number of urinary stone samples. It was recognized that Ca exists with low concentration, which indicates the presence of different calcium phases even with low percentages. In 33% of the urinary stones, the phosphorus (P) was not measured, but there were high concentrations of sulfur (S) and low concentrations of Ca up to 2.15 ± 0.05%. The ATR-FTIR results indicate that the most compounds of the present urinary stones were urea and cystine combined with low ratios of calcium oxalate and calcium phosphate compounds. The quantitative phase analysis of the XRD of selected samples proves the presence of the cystine, urea, and calcium oxalate phases with different weight percent.