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。     

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....     

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.     

尿液中的纳米晶体组分及其对草酸钙结石形成的影响

采用高分辨率透射电子显微镜、选区电子衍射、能谱分析和X射线衍射对草酸钙(CaOx)结石患者尿液中纳米晶体的组分进行了准确分析。这些技术检测到一水草酸钙(COM)、尿酸(UA)和磷酸钙(CaP)的存在,能谱分析检测到大量C,O,Ca和少量N和P等元素,表明尿纳米晶体的主要组分是COM,并含有少量的尿酸和磷酸盐。电子显微镜观察到CaOx结石患者尿纳米晶体的粒径主要分布在几十纳米,其结果与Scherer公式计算相符。采用不同孔径的微孔滤膜(0.45,1.2和3 μm)将尿液过滤后,得到的尿微晶衍射峰的数量随着滤膜孔径的增加而增加,表明尿微晶的种类增加。CaOx尿石的形成过程涉及尿液晶体的成核、生长、团聚和与细胞的粘附等过程。尿液中大量纳米COM晶体的存在是草酸钙结石形成的重要原因。纳米UA,CaP晶体能够作为晶巢促进草酸钙结石的形成。     

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。     

激光散射法对尿液中纳米微晶粒径及其分布的研究

泌尿系结石已经成为威胁人类健康的一种常见病、多发病,目前对其形成的机制尚不清楚。文章采用激光散射法测定了正常人尿液和尿石症患者尿液中纳米粒子的粒径和粒径分布,该方法快速准确、经济、容易操作。正常人尿液比尿石症患者尿液的稳定性好,归因于正常人尿液中纳米微晶尺寸分布均匀,不容易聚集,而尿石症患者尿液的纳米微晶尺寸分布不均匀,粒子间容易聚集而沉降。通过分析尿样稀释、离心或者用微孔滤膜过滤后体系的光强-自相关函数曲线,得到了制备稳定的尿样悬浮液的方法：尿样先稀释20%,然后离心或用1.2 μm微孔滤膜过滤,可得到稳定的尿液悬浮液。激光散射法结果与TEM检测结果一致。从尿液中存在的范德华力、尿液粘度、酸碱性、离子强度、尿液中纳米微晶的表面电荷和Zeta电位等方面解释了尿液稳定的原因。     

泌尿系结石组分分析方法及其研究进展

对泌尿系结石组分进行准确的分析可为治疗尿石症和预防其复发提供重要的参考。文章综述了现代仪器分析方法在草酸钙结石、磷酸盐结石、尿酸和尿酸盐结石及胱氨酸类结石等组分分析中的应用及其研究进展,这些技术包括拉曼光谱、差热-热重(TGA/DTA)、核磁共振(NMR)、高效液相色谱(HPLC)和傅里叶红外光谱(FTIR)等。     

CS-QT-TPP纳米颗粒的动态光散射分析

本文利用CS与TPP的交联作用包覆QT制备CS-QT-TPP纳米颗粒,并以动态光散射研究QT浓度、CS分子量及CS/TPP重量比对所得纳米颗粒粒径与Zeta电位的影响。结果表明,QT浓度由0.15mg/mL升至0.45mg/mL时粒径增大,而继续升至0.75mg/mL时粒径稍微减小;CS分子量越高,粒径越小;而CS/TPP重量比对粒径则无明显影响。CS-QT-TPP纳米颗粒粒径介于711~759nm之间。CS分子量较低时表面电位较小,而QT浓度与CS/TPP重量比则对Zeta电位无明显影响,CS-QT-TPP纳米颗粒表面均带正电,介于25.7~39.8mV之间。因此,QT浓度为0.75mg/mL、CS高分子量为380kDa及CS/TPP重量比为3/1时制备CS-QT-TPP纳米颗粒最佳。     

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.     

季铵盐型纳米气相二氧化硅衍生物的合成、表征及生物学活性

以纳米气相SiO₂为载体,以γ- 氯丙基三甲氧基硅烷作偶联剂,用N,N-二甲基十四烷基叔胺进行了季铵化反应制备季铵盐型纳米气相二氧化硅衍生物。用红外光谱,DSC和激光粒度Zeta电位仪对纳米气相二氧化硅季铵盐衍生物进行了表征和测定,用悬菌定量实验(Suspension quantitative test)研究了其抗菌性能。结果表明：(1) γ- 氯丙基三甲氧基硅烷通过与纳米气相二氧化硅表面羟基的反应键合到二氧化硅表面,随着γ-氯丙基三甲氧基硅烷的用量增加,纳米气相二氧化硅表面羟基被取代程度也增加;(2)纳米气相二氧化硅的零电位在pH 4.8,纳米气相二氧化硅季铵盐衍生物的零电位在pH 10.5,季铵盐的引入使其零电位发生了较大的位移;(3)所制备的纳米气相二氧化硅季铵盐衍生物对大肠杆菌、金黄色葡萄球菌以及白色念珠菌在振荡作用15 min后,平均抑菌率分别为99.99%,99.99%和94.12%。     

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.     

表面增强拉曼光谱快速检测尿液中的尿酸

表面增强拉曼光谱是一种表面灵敏度极高的“指纹”光谱技术,检测限可达单分子级别。它可以实现痕量物质的特异性识别及快速、无损检测,广泛应用于生命科学、电化学、环境安全等领域以及人们的日常生活中。通过种子生长法成功地实现了形貌均匀、尺寸可调的球形金纳米粒子的制备,并以此作为增强基底进一步探索其粒径对尿酸拉曼谱峰强度的影响。结果表明,金纳米粒子的尺寸显著影响其拉曼增强能力。在研究范围内,随着金纳米粒子尺寸的增加,其拉曼增强能力逐渐增加。在激光波长为638 nm时,150 nm的金纳米粒子具有最优的拉曼增强能力。这使得它们可适用于尿酸溶液的快速高灵敏度分析,检测限可达0.01 mmol·L-1。进一步的研究还表明,该方法可用于痕量尿酸的定量检测。在0.01～0.5 mmol·L-1范围内,尿酸的浓度与其特征拉曼峰640 cm-1处的峰强度之间呈线性关系,线性相关系数达0.98。将该方法用于真实样品(正常人体尿液)的快速检测,发现该方法不受尿液中其他成分的干扰,可以实现人体尿液中尿酸含量的快速测定。研究结果表明,以金纳米粒子作为基底的表面增强拉曼光谱方法可方便、快速地对尿液中尿酸的含量进行分析,极大地拓展了表面增强拉曼光谱在临床上的应用与研究。     

Folate-decorated chitosan/doxorubicin poly(butyl)cyanoacrylate nanoparticles for tumor-targeted drug delivery

A novel chitosan coated poly(butyl cyanoacrylate) (PBCA) nanoparticles loaded doxorubicin (DOX) were synthesized and then conjugated with folic acid to produce a folate-targeted drug carrier for tumor-specific drug delivery. Prepared nanoparticles were surface modified by folate for targeting cancer cells, which is confirmed by FTIR spectroscopy and characterized for shape, size, and zeta potential measurements. The size and zeta potential of prepared DOX-PBCA nanoparticles (DOX-PBCA NPs) were almost 174 ± 8.23 nm and +23.14 ± 4.25 mV, respectively with 46.8 ± 3.32% encapsulation capacity. The transmission electron microscopy study revealed that preparation allowed the formation of spherical nanometric and homogeneous. Fluorescent microscopy imaging and flow cytometry analysis revealed that DOX-PBCA NPs were endocytosed into MCF-7 cells through the interaction with overexpressed folate receptors on the surface of the cancer cells. The results demonstrate that folate-conjugated DOX-PBCA NPs drug delivery system could provide increased therapeutic benefit by delivering the encapsulated drug to the folate receptor positive cancer cells.     

Infrared Analysis of Urinary Stones,Using a Single Reflection Accessory and a KBr Pellet Transmission*

This work is a comparative study of two FTIR techniques applied to urinary stones analysis: single reflection diamond attenuated total reflection (ATR) and KBr pellet transmission (KPT). We show that the two methods allow the identification of all stone components. The ATR technique is more useful and rapid to identify the species without sample pretreatment. Nevertheless, KPT is more appropriate for components determination in urinary stones.

These techniques were applied to the study of a series of 313 calculi. The stone constituents were first identified by ATR, and in a second step, the proportion of each species present in the stone was determined by KPT in whole‐stone mixture.

The results obtained showed the presence of 11 different components classified as follows with the frequency of detection in the stones studied: calcium oxalate monohydrate (whewellite), 78.9%; carbapatite, 33.9%; calcium oxalate dihydrate (weddellite), 24%; uric acid anhydrous, 19.2%; ammonium hydrogen urate, 7%; struvite, 4.8%; cystine, 1%; ammonium sodium urate and other phosphates (amorphous carbonated calcium phosphate, brushite, whitlockite), each in less than 1%.     

Ultrasonic parameters of concentric laminated uric acid stones

Recently a new idea for the disintegration of urinary calculi based upon the large difference of the acoustic impedance inside urinary calculi was suggested. This large difference of acoustical impedance between the two main components of kidney stones, is confirmed in this paper for smooth laminated uric acid stones by two different experimental techniques measuring sound velocities: a surface contact and a submersion technique. Our measured values correlate well with the large differences of the earlier reported measured sound velocities. In general, the disintegration of a urinary stone can be described as follows: a urinary calculus is an inhomogeneous geometrical structure, and its structure plays an important role in the disintegration process.