肾茶提取物抑制小鼠草酸钙结石作用研究

目的研究肾茶提取物的抗结石作用。方法小鼠饲饮含乙二醇和氯化铵的水建立草酸钙肾结石模型，测定肾脏、尿液中草酸和钙的含量。肾脏病理切片观察，进行草酸钙结晶的评分。结果肾茶提取物能明显降低肾结石小鼠尿液及肾组织中草酸和钙含量，减少草酸钙结晶在肾组织中的沉积。结论实验结果提示，肾茶提取物可能通过降低尿液草酸钙浓度，抑制结晶在肾脏的沉积而发挥作用。     

尿大分子物对草酸钙晶体表面Zeta电位的影响

目的 :探讨尿大分子物对泌尿系结石形成的影响。方法 :用过饱和结晶及溶晶、透析方法分别从 10例草酸钙结石患者和 11例正常人尿中提取与草酸钙晶体结合的尿大分子物 ,即晶体基质 ,并观测晶体基质和结晶前、后尿大分子物对人工尿中一水草酸钙晶体表面 Zeta电位的影响。结果 :晶体基质最能使 Zeta电位负值增大 ,结晶前尿大分子物次之 ,结晶后尿大分子物作用最弱 ;结石患者尿大分子物及晶体基质的作用均小于相应正常对照。结论 :在草酸钙结晶过程中 ,尿大分子物可选择性结合到草酸钙晶体表面 ,改变晶体表面特征 ,抑制晶体的聚集。结石患者尿大分子物抑制活性不足与尿石形成有关。     

表没食子儿茶素没食子酸酯(EGCG)对草酸钙结石的体外研究

目的 观察表没食子儿茶素没食子酸酯(EGCG)对草酸钙结晶(Calcium oxalate,CaOx)的体外影响.方法 在体外研究中,人工合成CaOx尿液,并采用红外光谱法分析和电镜扫描观察EGCG对CaOx晶体溶液的表征影响.结果 红外光谱法分析结果显示在含有100μg/ml浓度EGCG的CaOx溶液形成一水草酸钙(COM)的比例显著降低.扫描电镜结果显示在含有在100μg/ml浓度EGCG的CaOx溶液下,形成COM和二水草酸钙(COD)晶体形态呈散在分布,同时抑制了COM形成.结论 EGCG可能有助于预防草酸钙结石的发生和形成.     

广金钱草抑制一水草酸钙结晶生长有效成分的研究

本文对广金钱草多糖类进行了提取和精制,并通过电导法观察精制前后对一水草酸钙结晶生长的抑制作用,发现精制后比精制前的作用更强。     

复方泽泻制剂的体外抑石作用及组方筛选

目的:研究复方泽泻制剂的体外抑石作用并筛选最佳组方.方法:采用正交实验方法,以体外草酸钙结晶溶解率为检测指标,将泽泻水提液(A)、金钱草水提液(B)、枸橼酸钾(C)和维生素 B6(D)四种有效成分按正交表进行实验,测定草酸钙结晶溶解率.结果:四种药物配伍制剂均能产生体外溶石作用( P < 0. 05),其中 A3 B3 C2 D1 配比组溶石率为22. 23% ,体外抑制草酸钙结晶效果最好(P < 0. 05).结论:泽泻水提液(A)、金钱草水提液(B)、枸橼酸钾(C)和维生素B6(D)四种药物合用在体外能起到良好的抑制结石作用,最佳组方配比为 A3 B3 C2 D1 ,即高剂量的泽泻和金钱草、中剂量的枸橼酸钾、小剂量的维生素 B6 混合时能最有效地抑制体外草酸钙结晶的形成.     

用偏光显微镜观察尿石的菱形结晶转变特征

文献中多认为在尿石结构中出现的菱形结晶是二水草酸钙的代表晶体。因此在分类上将具有菱晶结构特征的尿石归为二水草酸钙将具有鲕和鲕状结构的尿石归类为一水草酸钙。一水草酸钙多具有光滑的表面,而二水草酸钙则具有毛刺样外观,晶体特征非常显著。有的作者认为形成这样完好典型的菱形晶体是在过饱和液中缓慢生长起来的。     

焦磷酸盐、柠檬酸盐对草酸钙结晶形成和凝集的作用

一般认为,尿石形成的前题是结晶尿,但在正常人尿中往往也可见到草酸钙结晶。因此尿中结晶生长和凝集对结石形成更为重要。为研究焦磷酸盐、柠檬酸盐对草酸钙结晶生长和凝集的作用,本文设计了草酸钙结晶生长模型,以分析焦磷酸盐,柠檬酸盐在体外对草酸钙结晶生长,凝集的作用,并对草酸钙结晶生长模型作了研究。     

槲叶中化学成分抑制一水草酸钙结晶作用的研究

尿路结石是一种常见病 ,在我国的贵州、广东等地发病率较高。尿路结石的成分主要为一水草酸钙、二水草酸钙、磷灰石类、磷酸镁铵、尿酸及尿酸盐类、嘌呤类、胱氨酸结石和软结石等。其中 ,一水草酸钙出现机会最多 ,为防治尿路结石的重点研究对象。在正常人的尿液中 ,钙离子和草酸根离子的离子积大约是草酸钙溶度积的 1 70倍。这样的过饱和溶液不析出晶体是由于正常人的尿液中存在着结晶抑制剂 ,而尿路结石病人的尿液中缺少结晶抑制剂 ,就导致结石的形成。治疗结石的方法有超声波粉碎法、激光粉碎法、手术取石法、中药排石法等。在我国 ,中药…     

用旋转台法测定尿石中草酸钙晶体的过渡性质

近些年来,一般把菱形晶和信封状晶归属于二水草酸钙。且发现二水草酸钙不仅可以转化为一水草酸钙,而且动物实验证实这种转变是在固-固相中发生的。本文作者用偏光显微镜的锥光系统观察草酸钙结石薄片,发现菱形晶不是二水草酸钙,而是二水草酸钙向一水草酸钙转变的过渡晶体,为进一步证实这一结论,本文用偏光显微镜旋转台法测定了典型菱形晶颗粒的光学常数。材料和方法选经治疗排出的直径约在0.5cm以下的小结石30例。经自然干燥,常规磨片。在单偏     

草酸钙结晶在中药鉴别中的应用与分析

草酸钙结晶有以下几种形态:单晶、簇晶、针晶。草酸钙结晶在中药显微鉴别中具有重要意义。不是所有的植物都含有草酸钙结晶,且不同种类的植物有不同形状和大小的结晶,依据这一特征,在显微鉴定中,可用于鉴别不同种、属的药材或作为未知药材分类检索的辅助依据。1草酸钙结晶的类型及分布1·1草酸钙结晶的类型根据草酸钙结晶形态分类法,将草酸钙晶体分为3类:①簇晶(包括莲晶、球晶、聚晶);②单晶(包括方晶、砂晶、菱晶及长、短径近似的晶体);③针晶(包括柱晶、棒晶、杆晶)。1·2草酸钙结晶的分布1·2·1簇晶草酸钙晶体的形状为簇针形。其直径从…     

In vitro Evaluation of Terminalia arjuna on Calcium Phosphate and Calcium Oxalate Crystallization

Urinary stones are one of the oldest and the most common afflictions in humans. This disease has tormented humans since the earliest records of civilization. Ten percent of men and 3 % of women have a stone during their adult lives. Calcium containing stones are the most common comprising about 75 % of all urinary calculi, which may be in the form of pure calcium oxalate (50 %) or calcium phosphate (5 %) or a mixture of both (45 %). A number of plants have been mentioned in the Indian ayurvedic system, which plays a vital role in the inhibition of kidney stones. In the present study, the inhibitory potency of crude extracts or fractions of successive solvent extractions of Terminalia arjuna bark was evaluated on various stages of formation of calcium phosphate and on the growth of calcium oxalate monohydrate crystals in vitro. Results obtained indicated that Terminalia arjuna bark has the potential to inhibit the formation of both calcium phosphate and calcium oxalate crystals in vitro. Butanol fraction of Terminalia arjuna extract was the most effective in inhibiting formation of calcium phosphate and calcium oxalate crystals in vitro.     

Growth of calcium oxalate in gel systems.

Methods are described for growing calcium oxalate in silica and gelatin gels under different conditions. The results obtained indicate that, in silica gel, calcium oxalate grows into single individual crystals, twins, and rosettes. Bipyramidal calcium oxalate dihydrate crystals similar to those present in the urine of stone formers were prepared in the silica gel system. The gelatin gel offered a suitably structured substrate on which calcium oxalate monohydrate crystals grow into aggregates. The orientation pattern of calcium oxalate crystals suggests that the growth process is controlled by the stereospecificity of the gelatin medium supporting growth.     

Modulatory effects of N-acetylcysteine on hyperoxaluric manifestations in rat kidney

Hyperoxaluria is a condition where excessive oxalate is present in the urine. Many reports have documented free radical generation followed by hyperoxaluria as a consequence of which calcium oxalate deposition occurs in the kidney tissue. The present in vivo study was designed to investigate the potential of N-acetylcysteine in modulating hyperoxaluric manifestation induced by sodium oxalate in the rat kidneys. Male wistar rats in one group were administered single dose of sodium oxalate (70 mg/kg body weight) intraperitoneally to induce hyperoxaluric conditions and in the other group, rats were injected N-acetylcysteine (NAC) (200 mg/kg body weight) intraperitoneally, half an hour after sodium oxalate dose. The treatment is for a period of 24 h. N-acetylcysteine significantly reduced hyperoxaluria caused oxidative stress by reducing lipid peroxidation, restoring antioxidant enzymes activity in kidney tissue, followed by reduction in impairment of renal functioning. In addition, NAC administration reduced the number of calcium oxalate monohydrate (COM) crystals in the urine as observed under polarization microscope. Histological analysis depicted that NAC treatment decreased renal epithelial damage, inflammation and restored normal glomeruli morphology. Thus, it shows that use of an extraneous antioxidant may prove beneficial for combating the conditions of oxidative stress produced by hyperoxaluria.     

The cytotoxicity of oxalate, metabolite of ethylene glycol, is due to calcium oxalate monohydrate formation

Oxalate is a minor, but important metabolite of ethylene glycol and has been directly linked with acute and subchronic renal toxicity in ethylene glycol poisoning. Numerous studies have characterized the cytotoxicity of oxalate as including plasma membrane damage and organelle injury. Oxalate has two forms in vivo: oxalate ions and calcium oxalate monohydrate (COM) crystals that readily form in the presence of calcium. The present study was designed to compare the cytotoxicity of the oxalate ion and COM crystals in human and rat cells. In rat red blood cells, the oxalate ion did not increase hemolysis, while COM crystals produced hemolysis with a concentration-dependent increase. In human proximal tubule (HPT) cells in culture, COM suspensions, at concentrations >3 mM but with no oxalate ion, caused cytotoxicity as evidenced by the release of lactate dehydrogenase (LDH) into media. Cytotoxicity was not observed in HPT cells treated with oxalate solutions that contained no COM because EDTA prevented its formation. The cytotoxic effects of COM to HPT cells were potentiated by acidosis (pH 6.5), but not by glycolate, the major metabolite of ethylene glycol. The toxicity of COM to HPT cells and to proximal tubule cells from Wistar and F-344 rats, compared using both ethidium homodimer uptake and LDH leakage, increased in human and rat cells in a concentration-dependent manner. Rat cells were more sensitive to COM than HPT cells, but there were no apparent differences between the effects in Wistar cells and F-344 cells. These results demonstrate that COM crystals, and not the oxalate ion, are responsible for the membrane damage and cell death observed in normal human and rat PT cells and suggest that COM accumulation in the kidney is responsible for the renal toxicity associated with ethylene glycol exposure.     

Examination of the itch response from the raphides of the fishtail palm Caryota mitis.

The raphides in the mature fruit of the fishtail palm Caryota mitis Lour. were isolated by mechanical separation. These were shown by X-ray crystal analysis to be calcium oxalate monohydrate (Whewellite). The application of an aqueous suspension of the raphides to intact human skin results in an immediate, severe itch sensation. An investigation of this phenomenon appears to indicate that this is due solely to a mechanical action of the calcium oxalate needle and not to the previously postulated action of organic toxins or enzymes introduced through the skin by the penetrating action of the raphides.     

郑州及其周边地区泌尿系结石成分红外光谱分析

目的了解郑州及其周边地区泌尿系结石化学成分构成,为治疗及预防提供参考。方法收集郑州大学第二附属医院2008年7月—2012年12月门诊体外冲击波碎石后排出和住院患者手术取出的泌尿系结石标本2329例,使用红外光谱法进行定性分析。结果2329例泌尿系结石中单纯一水草酸钙类结石占17．0％（396／2329）,一水草酸钙、二水草酸钙混合类结石占19．2％（448／2329）,草酸钙类为主与碳酸磷灰石结石混合类占32．1％（748／2329）,碳酸磷灰石成分为主与草酸钙类混合类占13．4％（312／2329）,单一碳酸磷灰石成分占2．9％（68／2329）,单一无水尿酸结石占5．0％（116／2329）,尿酸或尿酸胺与草酸混合类3．8％（88／2329）。结论结石成分分析了解结石成因对于本地区治疗及预防具有重要的指导意义。     

Aluminum citrate inhibits cytotoxicity and aggregation of oxalate crystals

Calcium oxalate monohydrate (COM), which represents a major component of kidney stones, is an end metabolite of ethylene glycol. COM accumulation has been linked with acute renal toxicity in ethylene glycol poisoning. COM injures the kidney either by directly producing cytotoxicity to the kidney cells or by aggregating in the kidney lumen leading to the blockage of urine flow. The present studies were designed to examine whether aluminum citrate could reduce the toxicity of COM. Toxicity was determined in human proximal tubule cells by leakage of lactate dehydrogenase or uptake of ethidium homodimer and in erythrocytes by degree of hemolysis. Aluminum citrate significantly inhibited the leakage of lactate dehydrogenase from human proximal tubule cells and protected against cell death from COM. The inhibitory effect of aluminum citrate was greater than that of other citrate or aluminum salts such as sodium citrate, aluminum chloride, calcium citrate, ammonium citrate or potassium citrate. Aluminum citrate significantly inhibited the aggregation of COM crystals in vitro and decreased red cell membrane damage from COM. Aluminum citrate appeared to directly interact with COM, but not with the cell membrane. As such, aluminum citrate reduced the cytotoxicity by a physico-chemical interaction with the COM surface, and not by dissolving the COM crystals. These studies suggest that aluminum citrate may protect against tissue damage that occurs with high levels of oxalate accumulation, especially in ethylene glycol poisoning and possibly in hyperoxaluric states.     

Modulatory effect of Cyclea peltata Lam. on stone formation induced by ethylene glycol treatment in rats

The inhibitory effect of the root of Cyclea peltata Lam. on nephrolithiasis induced in rats by feeding with ethylene glycolated water (1%) for 35 days was summarized. Ethylene glycol administration led to oxalate stone formation, as indicated by its high level in urine. Complementary to this anion, the cation calcium level in urine was elevated. These two ions may have contributed to the formation of calcium oxalate stones. In addition to high serum potassium, a low serum magnesium level contributed to stone formation. Simultaneous administration of the powdered root of Cyclea peltata resulted in decreased urinary oxalate and calcium. Likewise, serum potassium was lowered and magnesium was elevated. These observations provided the basis for the conclusion that this plant inhibits the stone formation induced by ethylene glycol treatment.     

Physico-chemical alterations of urine in experimental hyperoxaluria: a biochemical approach with fucoidan

Urinary supersaturation-induced crystal formation has been attributed as one of the key factor for the pathogenesis/progression of lithogenesis. This study was aimed at investigating whether fucoidan, a naturally occurring sulfated glycosaminoglycan, could ameliorate the biochemical changes in urine induced by stone formation. Two groups of male albino Wistar rats (120+/-20 g) received 0.75% ethylene glycol (EG) for 28 days to induce hyperoxaluria, and one of them received sulfated polysaccharides (fucoidan from Fucus vesiculosus, 5 mg kg(-1), s.c.), commencing from the 8(th) day of the experimental period. One group was maintained as normal control group and another group served as drug control, which received sulfated polysaccharides. The urine collected from all the groups was analysed for changes in pH, volume, oxalate, calcium, phosphorus, uric acid, magnesium, citric acid and glycosaminoglycans. Urinary crystals were analysed with a light microscope. Renal tissues were studied under polarized light for deposition of crystals and also analysed for their oxalate and calcium content. The changes in extracellular matrix on crystal deposition were also evaluated. The urinary pH and volume were altered in rats treated with EG along with an increase in weight of the kidney. Further, administration of EG to rats increased the supersaturation of urine by escalating the levels of the stone-forming constituents, such as oxalate, calcium, phosphorus and uric acid, which was completely restored by fucoidan treatment. The decrease in the inhibitors, like citrate, magnesium and glycosaminoglycans, in urine was prevented by the co-treatment with fucoidan. In hyperoxaluric rats, there was an increased excretion of calcium oxalate monohydrate crystals in urine along with crystal deposition in renal tissues; this was prevented by fucoidan treatment. Fucoidan administration reversed even the tissue levels of calcium and oxalate. The increased accumulation of collagen and expression of transforming growth factor-beta(1) in hyperoxaluria was normalized on fucoidan administration. These results suggest that the physico-chemical alterations in urine produced during hyperoxaluria can be reversed by fucoidan administration.