草酸钙尿石症患者尿液和结石中凝血酶原片段检测及其意义

为比较正常人和尿石症患者尿液中凝血酶原片段1（UPTF1）在含量及其与草酸钙晶体的结合能力，以探讨UPTF1含量或功能异常与草酸结石形成的关系，用ELISA法检测正常人和尿石症患者24h尿液、用过饱和结晶法制备的晶体表面结合物质和结石基质中UPTF1的含量。结果发现尿石症患者尿液中能与草酸钙结合的UPTF1的浓度及其在24h尿中含量显著低于正常人组；UPTF1普遍存在于含钙结石中。结果表明：尿石症患者尿液中抑制结石形成的UPTF1明显减少可能是结石形成的重要原因。     

苄丙酮香豆素对实验性大鼠肾草酸钙结石形成的影响

目的：探讨Vit．K拮抗剂苄丙酮香豆素(商品名华法令)对大鼠肾草酸钙结石形成的影响。方法：采用乙二醇饮水和氯化铵灌胃作成石剂，30只Wistar大鼠随机分为对照组(A组)、成石组(B组)、华法令组(C组)。饲养4周后，检测大鼠肾组织钙含量和草酸钙晶体形成、24h尿钙、尿草酸含量及血生化指标。结果：成石组和华法令组肾组织中钙、镁含量，24h尿草酸及尿钙、镁排泄量差异无显著性意义；镜下观察发现：华法令组大鼠肾脏草酸钙结晶形成多于成石组，但组间比较差异无显著性意义。结论：苄丙酮香豆素对大鼠肾草酸钙结石的形成无显著影响。     

草酸钙结石形成对肾组织bikunin和IαI表达的影响

目的研究肾草酸钙结石形成对肾组织bikunin基因和间α胰蛋白酶抑制物(IαI)蛋白表达的影响,探讨bikunin在尿结石形成中的意义。方法诱导实验性大鼠肾草酸钙结石模型,收集结石大鼠、正常大鼠、临床肾结石和非结石患者每组各8例的肾组织标本。采用免疫组化、逆转录聚合酶链反应(RT-PCR)和计算机图像分析技术分别检测所有大鼠和人肾组织中bikuninmRNA和IαI蛋白的表达水平。结果正常大鼠和非结石患者肾组织均存在bikuninmRNA和IαI蛋白的表达。肾草酸钙结石形成后,结石大鼠肾组织IαI蛋白的灰度值和bikuninmRNA的相对表达水平分别为198.43±15.17、0.70±0.14;肾结石患者肾组织IαI蛋白的灰度值和bikuninmRNA的相对表达水平分别为263.25±17.41、1.27±0.13,分别和对照组相比,均显著增加(P<0.05)。结论Bikunin作为构成IαI的轻链结构,在肾草酸钙结石形成后,bikuninmRNA的表达迅速增强,提示机体通过肾脏合成更多的bikunin来抑制肾草酸钙结石的形成。     

Fibronectin inhibits endocytosis of calcium oxalate crystals by renal tubular cells

BACKGROUND: Fibronectin (FN; 230 kDa) is a multifunctional alpha2-glycoprotein distributed throughout the extracellular matrix and body fluids. We recently reported that FN has a protective effect against injury of renal tubular cells by exposure to oxalate and calcium oxalate (CaOX) crystals and inhibits the adhesion of CaOX crystals to renal tubular cells. In the study presented here, we investigated whether FN has inhibitory effect on crystal endocytosis by renal tubular cells. METHODS: The inhibitory effect of FN on endocytosis of CaOX crystals by MDCK cells was examined by using a radioactivity uptake assay. Also, crystal endocytosis by cells was morphologically assessed by means of transmission electron microscopy (TEM). RESULTS: FN had inhibitory effects on CaOX crystal endocytosis by MDCK cells. The morphological TEM study showed that few crystals were taken into cells when FN was added compared to the number of crystals when FN was not added. CONCLUSION: We found that FN had the inhibitory effects on the interaction between crystals and renal tubular cells, including the adhesion or endocytosis of crystals by cells.     

Sialic acid concentrations in the urine of men with and without renal stones

Summary It has been suggested that urinary sialidase may play a role in the formation of renal stones. The present study was therefore undertaken to compare spectrophotometrically the different types of sialic acid concentrations and sialidase activities in fresh first morning urine specimens of men (21–65 years) with (13) and without (9) calcium oxalate renal stones. Although the free urinary sialic acid concentrations of the two groups of men were statistically about the same (P=0.0614), the total (P=0.003) and bound (P=0.0012) urinary sialic acid concentrations differed significantly. Both the total and bound sialic acid concentrations were lower in the urine specimens of the stone patients than in their healthy counterparts. This decrease in urinary sialic acid concentrations was firstly thought to be the result of elevated breakdown enzymes of sialic acid, which would favour the production of pyruvate. However, spectrophotometric determinations of the endogenous pyruvate concentrations of the two types of urine specimens did not differ significantly (P=0.0708). Secondly, the decrease in total urinary total sialic acid concentration of stone patients, could be attributed to less sialic acid synthesis or less renal excretion. Therefore, the same experiments were repeated using serum of 13 patients and 9 healthy men. Conversely, the total (P=0.4425) and bound (P=0.2850) serum sialic acid concentrations were found to be similar in the two types of subjects. However, the free serum sialic acid concentration of stone patients was significantly lower than in the healthy subjects (P=0.0062). This phenomenon is also reflected in the average ratio for serum free: bound sialic acid in healthy and stone patients, 1:7.9 and 1:18.7 respectively (P=0.0009). The lower free serum sialic acid concentration may lead to lower renal excretions of sialic acid. This may explain the decrease in total urinary sialic acid concentration in stone patients. The lower bound urinary sialic acid concentrations in patients was also reflected in the urinary free: bound sialic acid ratio for healthy (1:2.3) and stone patients (1:1.3). The difference between these two groups of men was highly significant (P=0.0001). This phenomenon might be explained by the urinary sialidase activities, which was spectrophotometrically determined at 334 nm at 37°C of 11 patients with stones and 17 healthy men. The ages of both groups of men were the same (P=0.326). An increase in urinary sialidase activity was observed with the stone patients (P=0.00001) when compared to specimens of healthy men. This might explain the decrease in urinary bound sialic acid concentration of the stone group. It seems from these results that the urinary concentration of sialic acid and the activity of urinary sialidase, may play a role in the pathogenesis of the multifactorial disease, urolithiasis.     

Effects of different doses of alkaline citrate on urine composition and crystallization of calcium oxalate

Summary Prophylactic treatment with alkaline citrate in patients with recurrent calcium oxalate (CaOx) stone disease results in reduced CaOx supersaturation and increased urinary citrate. The effects of a single evening dose were compared with those of two and three daily doses in six recurrent CaOx stone formers with hypercalciuria, hypocitraturia or raised calcium/citrate quotients. While on a standardized hospital diet the patients were given 7.5 g (28 mmol) of sodium potassium citrate (URALYT-U) in one, two, and three doses. Fractional urine collections during 24 hours were analyzed for pH, composition, and crystallization risk (CR). All dosage regimens had favourable effects on urinary calcium, citrate, calcium/citrate quotients, and CaOx-CR. The most sustained effect was recorded with three divided doses. Single evening doses resulted in the most pronounced effects between 22.00–06.00 h, thereby counteracting the increased risk of CaOx crystallization during that period. In terms of 24 h urine composition the best effect was recorded with alkaline citrate administered three times daily, but because of the favourable response by a single evening dose between 22.00–06.00 h the assumption was made that this dosage regimen might be sufficient to reduce the risk of CaOx crystallization and stone formation. However, the validity of such an assumption can only be established by long-term clinical studies.     

一种中西药复方制剂(PESM)对大鼠实验性肾结石形成的抑制作用

用乙二醇法诱导大鼠产生草酸钙结石，用45~Ca示踪测定法了解中草药复方制剂（PESM）对草酸钙结石形成的抑制作用。结果显示，实验组肾脏放射性强度明显减少（实验组3.47±3.52cpm／mg，对照组10.89±14.24cpm／mg）。干肾重量明显下降（实验组306.0±47.0mg，对照组343.1±59.4mg），说明PESM能明显抑制肾脏草酸钙结石的形成。     

Effects of naftidrofuryl oxalate, a 5HT2 antagonist, on neurotransmission and transduction systems in the gerbil hippocampus

We investigated the effects of age and naftidrofuryl oxalate (Naftidrofuryl), a 5-HT₂ antagonist, on neurotransmission and transduction systems in the gerbil hippocampus using quantitative autoradiography. [³H]Quinuclidinyl benzilate (QNB), [³H]cyclohexyl-adenosine (CHA), [³H]MK-801, and [³H]muscimol were used to label muscarinic acetylcholine, adenosine A1, N-methyl-d-aspartate (NMDA), and γ-aminobutyric acid-A (GABA_A) receptors, respectively. [³H]PN200-110 labeled L-type Ca²⁺ channels. [³H]Forskolin, [³H]cyclic adenosine monophosphate (cAMP), [³H]phorbol 12,13-dibutyrate (PDBu), and [³H]inositol 1,4,5-triphosphate (IP₃) were used to label adenylate cyclase, cAMP-dependent protein kinase, protein kinase C (PKC), and IP₃ receptors, respectively. Approximately 20% reductions in [³H]QNB, [³H]forskolin, and [³H]PDBu binding were observed in the hippocampus of 9-month-old gerbils in comparison with 5-week-old gerbils. Treatment with Naftidrofuryl (10 mg/kg, i.p., once a day for 7 days) ameliorated these reductions. No changes were found in [³H]CHA, [³H]MK-801, [³H]muscimol, [³H]PN200-110, [³H]cAMP, and [³H]IP₃ binding. The results suggest that Naftidrofuryl may have beneficial effects on the age-related alterations in signal transmission and transduction systems in the brain. Because the acetylcholine system, adenylate cyclase, and PKC are considered to be involved in learning and memory processes, the result may have clinical implications.     

Acute Oxalate Nephropathy: A New Etiology for Acute Renal Failure Following Nonrenal Solid Organ Transplantation

Acute renal insufficiency (ARI) is a frequent complication of nonrenal solid organ transplantation and may be responsible for an unfavorable outcome, particularly if dialysis is required. The etiology of post-transplantation ARI is poorly understood, with only isolated clinical cases being reported, most imputed to drug toxicity. We report here, the first three observations of irreversible ARI associated with acute oxalate nephropathy (AON) in the course of nonrenal organ transplants: a lung transplant and a lung-liver transplant in two patients with mucoviscidosis, and a cardiac transplant. The diagnosis of AON was made histologically. In all three cases, the ARI supervened after prolonged consumption of antibiotics capable of interfering with the colonic flora, and leading to enteric hyperoxaluria. The recognition of AON as a cause of post-transplantation, ARI underlines hyperoxaluria and digestive hyperabsorption of oxalate as specific risk factors for AON and should permit better posttransplant care of these patients.     

Nature and significance of calcium oxalate crystals in normal human thyroid gland

To elucidate the significance and nature of calcium oxalate crystals in the thyroid, we studied these crystals clinicopathologically and immunohistochemically in 182 normal thyroids from patients autopsied within 5 h of death. Under polarized light, calcium oxalate crystals showed brilliant birefringence and were invariably found within the colloid. The crystals were found in 73.1% of all cases but were more prevalent and denser in older individuals, with the highest prevalence (85.2%) being observed in those over 70 years of age. No crystals were seen in those under 10 years of age. Although underlying diseases seemed to have little influence, post-mortem delay apparently affected the prevalence and density of occurrence since the crystals tended to disappear with hours after death. An immunohistochemical study using anti-thyroid hormone antibodies revealed that the crystals were within negatively or weakly stained colloid and were not common in strongly stained colloid. These findings support the hypothesis that the occurrence of calcium oxalate crystals in normal human thyroid is associated with a low functional state of the thyroid follicles.