肾脏热物性测量及低温下细胞形态分析

肾脏热物性参数获取和微观结构的观察,对研究冰温延时保存器官的机理非常重要。采用差示扫描量热仪测量了离体肾脏导热系数、冰点和器官保存液冰点;利用低温显微系统对肾脏组织不同保存温度及不同降温速率等状态条件,做了细胞形态的观察与分析。研究结果认为,鲜活肾脏导热系数值对肾脏冷却速率影响较大,同时发现在实验条件范围内较小的降温速率对细胞的损伤较轻。     

High-field magnetic resonance imaging using solenoid radiofrequency coils

High-resolution magnetic resonance imaging using dedicated high-field radiofrequency micro-coils at 16.4 T (700 MHz) was investigated. Specific solenoid coils primarily using silver and copper as conductors with enamel and polyurethane coatings were built to establish which coil configuration produces the best image. Image quality was quantified using signal-to-noise ratio and signal variation over regions of interest. Benchmarking was conducted using 5-mm diameter coils, as this size is comparable to an established coil of the same size. Our 1.4-mm-diameter coils were compared directly to each other, from which we deduce performance as a function of conductor material and coating. A variety of materials and conductor coatings allowed us to choose an optimal design, which we used to image a kidney section at 10-micron resolution. We applied zero-fill extrapolation to achieve 5-micron resolution.     

High‐contrast Noninvasive Imaging of Kidney Clearance Kinetics Enabled by Renal Clearable Nanofluorophores

Noninvasive imaging of kidney clearance kinetics (KCK) of renal clearable probes is key to studying unilateral kidney function diseases, but such imaging is highly challenging to achieve with in vivo fluorescence. While this long‐standing challenge is often attributed to the limited light penetration depth, we found that rapid and persistent accumulation of conventional dyes in the skin “shadowed” real fluorescence signals from the kidneys and prevented noninvasive imaging of KCK, which, however, can be addressed with renal clearable nanofluorophores. By integrating near infrared emission with efficient renal clearance and ultralow background interference, the nanofluorophores can increase kidney‐contrast enhancement and imaging‐time window by approximately 50‐ and 1000‐fold over conventional dyes, and significantly minimize deviation between noninvasive and invasive KCK, laying down a foundation for translating in vivo fluorescence imaging in preclinical noninvasive kidney function assessments.     

Evaluation of an activated carbon from olive stones used as an adsorbent for heavy metal removal from aqueous phases

The performance of a microporous activated carbon prepared chemically from olive stones for removing Cu(II), Cd(II) and Pb(II) from single and binary aqueous solutions was investigated via the batch technique. The activated carbon sample was characterized using N₂ adsorption–desorption isotherms, SEM, XRD, FTIR, and Boehm titration. The effect of initial pH and contact time were studied. Adsorption kinetic rates were found to be fast and kinetic experimental data fitted very well the pseudo-second-order equation. The adsorption isotherms fit the Redlich–Peterson model very well and maximum adsorption amounts of single metal ions solutions follow the trend Pb(II) > Cd(II) > Cu(II). The adsorption behavior of binary solution systems shows a relatively high affinity to Cu(II) at the activated carbon surface of the mixture with Cd(II) or Pb(II). An antagonistic competitive adsorption phenomenon was observed. Desorption experiments indicated that about 59.5% of Cu(II) and 23% of Cd(II) were desorbed using a diluted sulfuric acid solution.     

Searching for Potential Markers of Glomerulopathy in Urine by HS-SPME-GC×GC TOFMS

Volatile organic compounds (VOCs) exiting in urine are potential biomarkers of chronic kidney diseases. Headspace solid phase microextraction (HS-SPME) was applied for extraction VOCs over the urine samples. Volatile metabolites were separated and identified by means of two-dimensional gas chromatography and time of flight mass spectrometry (GC × GC TOF MS). Patients with glomerular diseases (n = 27) and healthy controls (n = 20) were recruited in the study. Different VOCs profiles were obtained from patients and control. Developed methodology offers the opportunity to examine the metabolic profile associated with glomerulopathy. Four compounds found in elevated amounts in the patients group, i.e., methyl hexadecanoate; 9-hexadecen-1-ol; 6,10-dimethyl-5,9-undecadien-2-one and 2-pentanone were proposed as markers of glomerular diseases.     

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 %).

     

Exploring the mechanisms of renoprotection against progressive glomerulosclerosis

In this review, I introduce the strategy developed by our laboratory to explore the mechanisms of renoprotection against progressive glomerulosclerosis leading to renal death. First, I describe the experimental rat model in which disturbances of vascular regeneration and glomerular hemodynamics lead to irreversible glomerulosclerosis. Second, I discuss the possible mechanisms determining the progression of glomerulosclerosis and introduce a new imaging system based on intravital confocal laser scanning microscopy. Third, I provide an in-depth review of the regulatory glomerular hemodynamics at the cellular and molecular levels while focusing on the pivotal role of Ca(2+)-dependent gap junctional intercellular communication in coordinating the behavior of mesangial cells. Last, I show that local delivery of renoprotective agents, in combination with diagnostic imaging of the renal microvasculature, allows the evaluation of the therapeutic effects of angiotensin II receptor and cyclooxygenase activity local blockade on the progression of glomerulosclerosis, which would otherwise lead to renal death.     

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.     

五种补肾中成药物中微量铝分析

用Ａｌ－ＣＡＳ－ＯＰ－１０分光光度法测定了五种补肾中成药中铝含量。结果表明,五种中成药中铝含量有一定的差异。本实验结果为进一步研究铝与补肾中成药的功效关系提供了有用数据。     

Speciation of functional groups formed on the surface of ammoxidised carbonaceous materials by XPS method

X-ray photoelectron spectroscopy (XPS) has been used to investigate the fate of nitrogen functional groups present in carbonaceous materials obtained from European plum (Prunus domestica) stones and modified by ammonia-air mixture at 250 or 300 °C. Peaks have been found in the XPS patterns, corresponding to different nitrogen functional forms i.e. pyrrolic, pyridinic, pyridone, amine and chemisorbed nitrogen oxides. It has been found that the distribution of nitrogen functional forms changes as a result of the modification processes.