结石患者和健康对照者尿微晶生长、聚集过程的比较研究

采用扫描电子显微镜(SEM)和X-射线粉末衍射仪(XRD)比较研究了5例泌尿系结石患者和5名健康对照者的尿微晶的生长动力学差异。随着生长时间(t)增加,结石患者尿微晶尺寸不断增大,粒径从t=1 h时的约(6±4)μm增加到t=48 h的(29±17)μm,但微晶数密度从(1 400±300)mm-2逐渐减少至(450±140)mm-2,表明在患者尿液中微晶的形成过程为生长控制;相比之下,在对照者尿液中,随着t从1 h增加48 h,尿微晶数密度从(850±260)mm-2减少至(610±210)mm-2,微晶尺寸从(6±5)μm增加至(15±9)μm,这表明其生长过程同时为成核控制和生长控制。上述差异归因于对照者尿液中抑制剂的浓度和活性均比结石患者的高,更能抑制尿微晶的生长和聚集。     

不同纵横比一水草酸钙晶体的合成、表征、吸附性能及其对肾上皮细胞的毒性差异

合成了长宽比分别为1∶2、1∶3、1∶4和1∶5的4种一水草酸钙(COM)晶体COM-1∶2、COM-1∶3、COM-1∶4和COM-1∶5,采用X射线衍射、傅里叶变换红外光谱、扫描电子显微镜(SEM)、ζ电位仪和比表面测试仪等对其理化性质进行了表征。SEM图片显示晶体的宽度相近,但长度分别为(3±0.3)μm、(5.2±0.3)μm、(7.0±0.7)μm和(8.8±1.2)μm。随着反应温度升高,生成的晶体长度变长;搅拌速度越大,生成的晶体尺寸越小;随着添加剂明胶的浓度减小,COM晶体的(101)面被拉长。细胞活力、细胞总死亡率和活性氧检测表明,不同长宽比COM对人肾近端上皮细胞(HK-2)的毒性大小为COM-1∶2>COM-1∶3>COM-1∶4>COM-1∶5>对照组,SEM检测证明4种COM晶体均能够黏附到细胞表面。毒性差异与以下各原因呈正相关：晶体大比例的(101)晶面、大的比表面积、大的细胞-晶体剪切应力。     

The pathogenesis of Randall's plaque: a papilla cartography of Ca compounds through an ex vivo investigation based on XANES spectroscopy

At the surface of attached kidney stones, a particular deposit termed Randall's plaque (RP) serves as a nucleus. This structural particularity as well as other major public health problems such as diabetes type‐2 may explain the dramatic increase in urolithiasis now affecting up to 20% of the population in the industrialized countries. Regarding the chemical composition, even if other phosphate phases such as whitlockite or brushite can be found as minor components (less than 5%), calcium phosphate apatite as well as amorphous carbonated calcium phosphate (ACCP) are the major components of most RPs. Through X‐ray absorption spectroscopy performed at the Ca K‐absorption edge, a technique specific to synchrotron radiation, the presence and crystallinity of the Ca phosphate phases present in RP were determined ex vivo. The sensitivity of the technique was used as well as the fact that the measurements can be performed directly on the papilla. The sample was stored in formol. Moreover, a first mapping of the chemical phase from the top of the papilla to the deep medulla is obtained. Direct structural evidence of the presence of ACCP as a major constituent is given for the first time. This set of data, coherent with previous studies, shows that this chemical phase can be considered as one precursor in the genesis of RP.     

Carbon stable isotope composition of modern and archaeological Cornelian cherry fruit stones: a pilot study

The carbon stable isotope content of Cornelian cherry stones collected from wild tree stands in Serbia, SE Europe, was measured using elemental analyser-isotope ratio mass spectrometry, with the aim of recording natural carbon isotope composition of the fruit stones and its possible variation. The results show a significant variation in the carbon isotope values; we identified several environmental factors that, along with a number of other possible determinants, likely contributed to this variation. The obtained data are compared with the measurement of carbon isotope content of an archaeological specimen of Cornelian cherry stone discovered at the Neolithic site of Vin?a (ca. 5600–4500 BC) in Serbia. Notwithstanding the limitedness of the data and the complexity surrounding carbon fractionation and the isotopic variation, it is suggested that the differences/similarities in carbon isotope ratios between modern and archaeological Cornelian cherry stones, when measured for much larger assemblages, could potentially offer a glimpse into growing conditions of Cornelian cherry trees in the past.     

Lipidomics based on liquid chromatography-high resolution mass spectrometry reveals the protective role of peroxisome proliferator-activated receptor alpha on kidney stone formation in mice treated with glyoxylate

Few studies have examined the relationship between lipid metabolism and kidney stone formation, particularly the role of key lipid regulatory factors in kidney stone formation. We evaluated the effect of the lipid regulatory factor-peroxisome proliferator-activated receptor alpha on the formation of renal stones in mice by injecting them with glyoxylate followed by treatment with either a peroxisome proliferator-activated receptor alpha agonist fenofibrate or an antagonist GW6471 (GW). Liquid chromatography coupled with trapped ion mobility spectrometry-quadrupole-time-of-flight mass spectrometry-based lipidomics was used to determine the lipid profile in the mouse kidneys. Histological and biochemical analyses showed that the mice injected with glyoxylate exhibited crystal precipitation and renal dysfunction. Crystallization decreased significantly in the fenofibrate group, whereas it increased significantly in the GW group. A total of 184 lipids, including fatty acyls, glycerolipids, glycerophospholipids, and sphingolipids differed significantly between the mice in the model and control groups. Peroxisome proliferator-activated receptor alpha activity negatively correlated with glyoxylate-induced kidney stone formation in mice, which may be related to improved fatty acid oxidation, maintenance of ceramide/complex sphingolipids cycle balance, and alleviation of disorder in phospholipid metabolism.