Morphological analysis of renal cell culture models of calcium phosphate stone formation

Cell culture models of calcium phosphate renal stone formation were established using the MDCK cell line. Renal microliths were detected within pseudocysts in three-dimensional soft agar cultures, and were also observed in the basal region of cells lining the cell sheet, and immediately beneath domes or blisters in monolayers and collagen gel cultures. Light and scanning electron microscopy indicated that these microliths had a similar lamellated and spherical appearance to those in humans. These microliths were first detected microscopically after 21 days of culture, and were found to be composed of calcium phosphate by X-ray and microinfrared spectroscopic analyses. These culture models may provide a powerful new tool to study the pathogenesis of renal stone diseases and/or calcium phosphate stone formation in humans and animals.     

载银磷酸锆纱布对烧伤创面常见细菌作用的实验研究

目的 了解载银磷酸锆纱布对烧伤大鼠创面感染常见细菌的抗菌效力。方法制作Wistar大鼠烫伤(以下称烧伤)感染模型，采用试管双倍稀释法测定载银磷酸锆及磺胺嘧啶银的最低抑菌浓度(MIC)及最低杀菌浓度(MBC)。观察大鼠创面用磺胺嘧啶银纱布、普通尢菌纱布、载银磷酸锆纱布(小水洗及水洗20次)后痂下组织的细菌计数和对创面愈合的作用。结果载银磷酸锆对金黄色葡萄球菌、铜绿假单胞菌、大肠竹菌的MIC各为8、8、16mg／L，MBC各为16、8、32mg／L，为磺胺嘧啶银的2～8倍?大鼠创面用未水洗的载银磷酸锆纱布覆盖后，痂下细菌计数比用磺胺嘧啶银纱布低91％，比普通无菌纱布低99％未水洗的载银磷酸锆纱布对创面愈合的作用明显优于其他两种纱布，且其痂下组织细菌计数与水洗20次的效银磷酸锆纱布比较，差异无显著性意义(P＞0．05)。结论载银磷酸锆埘烧伤创面感染常见细菌有较强的抑制和杀灭作用，其敷料可作为治疗措施中新的选择。     

Correlation between 1.25 dihydroxyvitamin D serum levels and fractional rate of intestinal calcium absorption in hypercalciuric nephrolithiasis. role of phosphate

Summary Different mechanisms could explain the elevated calcium elimination, the main cause of calcium oxalate renal stones. Our results suggest that phosphate levels are decreased in patients with absorptive hypercalciuric nephrolithiasis and elevated serum dihydroxyvitamin D. This could be the reason why in this group of patients oral phosphate treatment prevented hypercalciuria and renal lithiasis.This work was supported by FlSss 89/0799     

Effect of adiposity on plasma lipid transfer protein activities: a possible link between insulin resistance and high density lipoprotein metabolism

Abstract. The mechanisms responsible for the decreased high density lipoprotein (HDL) cholesterol levels associated with obesity and insulin resistance are not well understood. Lecithin: cholesterol acyltransferase (LCAT) and cholesterol ester transfer protein (CETP) are key factors in the esterification of cholesterol in HDL and the subsequent transfer of cholesteryl ester towards apolipoprotein B-containing lipoproteins. Phospholipid transfer protein (PLTP) may be involved in the regulation of HDL particle size. We therefore measured the activities of LCAT, CETP and PLTP using exogenous substrate assays, as well as lipids, lipoproteins, insulin and C-peptide in fasting plasma from eight healthy obese men (body mass index >27 kg m^-2) and 24 non-obese subjects. The obese men had lower levels of HDL cholesterol (P<0·05) and higher levels of plasma triglycerides (P<0·05), insulin (P<0·05) and C-peptide (P<0·01), as compared to the quartile of subjects with the lowest body mass index (BMI <22·4 kg m^-2). CETP and PLTP activities were elevated in the obese men by 35% (P<0·01) and by 15% (P<0·05), respectively. LCAT activity was comparable among the quartiles. Linear regression analysis showed that CETP activity was positively correlated with body mass index (P<0·02), fasting blood glucose (P7lt;0·05) and plasma C-peptide (P<0·05). PLTP activity was positively related to body mass index (P<0·01), waist to hip circumference ratio (P<0·001), as well as to fasting blood glucose (P<0·05) and plasma C-peptide (P<0·05) It is concluded that the activities of CETP and PLTP are influenced by adiposity and possibly by insulin resistance. Elevated lipid transfer protein activities may provide a mechanism that contributes to alterations in HDL in insulin resistant states.     

ACUTE EFFECT OF ETHANOL ON RENAL ELECTROLYTE TRANSPORT IN THE RAT

1. Despite human and animal studies, the direct effect of ethanol on renal water and electrolyte transport is poorly understood. The acute effect of increasing plasma concentrations of ethanol was evaluated in a water diuretic anaesthetized rat model which inhibits endogenous arginine vaso-pressin (AVP) release. 2. Ethanol at a plasma concentration of 1.69 ±0.28 mmol/L produced an immediate increase in urine flow (174 ± 11 μL/min pre-ethanol and 189 ± 13 and then 206 ± 12 μL/min during the ethanol infusion; P<0.001) as well as an increase in fractional sodium excretion (0.17 ± 0.04 to 0.28 ± 0.05 and 0.27 ± 0.05%; P<0.001). There was also a brief phosphaturia. These increases in electrolyte excretion had returned to control values by 20 min despite a further increase in the plasma ethanol concentration. 3. The urinary excretion of potassium, calcium and magnesium was not altered nor was glomerular filtration rate or renal plasma flow. 4. Ethanol at a mean concentration of 1.60 mmol/L did not alter the action of a maximal concentration of AVP (75 ng/kg) on water or electrolyte transport. However, the antidiuretic effect of a submaximal concentration of AVP (7.5 ng/kg) was augmented by ethanol at concentrations of 1.63 and 0.98 mmol/L. 5. These studies suggest that the ethanol induced diuresis commonly ascribed to inhibition of AVP secretion may also be due to other intrarenal effects of ethanol, possibly acting within the proximal tubule. These results also confirm recent in vitro findings that while ethanol does not inhibit the action of a maximal concentration of AVP, it does modulate the effects of lower AVP concentrations.     

胆固醇酯转运蛋白基因多态性在多囊卵巢综合征中的初步研究

目的:探讨胆固醇酯转运蛋白(CETP)在PCOS患者中的基因多态性和血脂、性激素的关系,以进一步认识PCOS脂代谢的特点。方法:应用PCR酶切方法检测108例PCOS患者及60例对照组的CETPTaqIB位点基因多态性。结果:CETPTaqIB基因频率及基因型分布在两组间分布差异无显著性。结论:CETPTaqIB基因多态性影响PCOS患者的HDLC水平,该基因在PCOS患者分布与正常人群分布无差异性。     

新型骨水泥粘接固定骨折的动物实验研究

目的：应用磷酸镁骨水泥(magnesium phosphate cement，MPC)粘接固定家兔胫骨平台骨折，探讨其治疗效果、粘接和降解机理。方法：20只家兔分为两组，第1组15只，第2组5只，通过开放截骨法建立家兔双侧胫骨平台骨折模型。第1组：实验组用MPC骨水泥固定，对照组用“L”形钢板固定。第2组：实验组也同样用MPC骨水泥固定，而对照组作空白对照。通过大体观察、影像学、组织学及电解质检查，探讨MPC骨水泥治疗骨折的效果、对体内电解质的影响、粘接和降解机理。结果：6周后实验组都获得稳定的骨折愈合，没有发现骨折错位及延迟愈合，MPC骨水泥逐渐被吸收，对体内电解质无明显影响，其对骨折的治疗和钢板固定组达到同样的治疗效果。而空白对照侧均出现骨折错位、畸形愈合。通过对标本的组织学检查发现其粘接机理为镶嵌固定，并通过溶解而逐步降解。结论：MPC骨水泥具有一定的粘接强度，能降解，对体内电解质干扰小，是一种较为理想的骨水泥，可以用于骨折的粘接固定。     

Distal radial fractures Injectable calcium phosphate bone cement versus conventional treatment

AMEDLINEsearchwasconductedtoidentifystudiespublishedfromJanuary1999toMarch2004thatcom-paredinjectablecalciumphosphatebone(NorianSRS)cementwithconventionaltreatmentindistalradialfrac-tures.Fromalistof13articlesidentifiedfromthesearchstrategy,fourarticleswe…