Bacterial superantigen enhances cytokine production by T-helper lymphocyte subset-2 cells and modifies glomerular lesions in experimental immunoglobulin a nephropathy

Background The purpose of this study was to examine the effects of bacterial suporantigens, which can derange the immune response and contribute to the renal lesions of immunoglobulin A (lgA) nephropathy. Methods Twenty-five micrograms of a bacterial superantigen, staphylococcal enterotoxin B (SEB), was injected into IgA nephropathy-prone ddY mice intrathymically when they reached 6 weeks of age. Evaluation included measurement of albumin excretion in urine, immunoglobulin concentration, and lymphokine production in vitro, as well as analysis of T-cell receptor expression in splenic T-cell subsets and examination of renal histology by light and fluorescence microscopy. Results At 40 weeks of age, the serum level of IgA in these mice was substantially increased and the number of Vβ8⁺ CD4⁺splenic T-cells was significantly decreased compared with measurements in untreated controls. Both control and SEB-treated mice excreted less than 30 μg/mL of urinary albumin. In mice given SEB, the amount of interleukin 2 (IL-2) and tumor necrosis factor-α (T helper 1 [Th1]-type cytokines) produced by the in vitro-stimulated lymphocytes significantly decreased. whereas that of interleukin 4 (IL-4) and interleukin 6 (IL-6) (Th2-type cytokines) markedly increased compared with measurements in control mice. At 40 weeks of age, mice given SEB showed marked glomerular hypercellularity and enhanced glomerular C3 deposition by renal histology, compared with control mice. Conclusion These results suggest that bacterial superantigen SEB may modify glomerular lesions through activating Th2 cells, while inducing deletion of Th1 cells in this experimental model.     

血浆中高级糖化终产物的水平与糖尿病并发症的关系研究

目的 探讨高级糖化终产物与糖尿病并发症的关系。方法 采用本实验室自行研制的竞争性酶联免疫吸附分析方法，测定了糖尿病有并发症组病人血浆95例，糖尿病无并发症组人血浆65例，正常对照65例。结果：在糖尿病有并发症组中，高级糖化终产物（AGEs）浓度[（6．625（1．691）U／mL，n=95]明显高于糖尿病无并发症组[（5．904（2．071）U／mL，n=65，P=0．017]，也明显高于正常人组[（5．337（1．138，n=65，p〈0．005]。以有无并发症为应变量进行多元logistic回归分析显示，血浆AGEs浓度〉6．085U／ml者，糖尿病并发症发生的危险性增加（OR值为2．989，95％可信限为1．407—6．350）。多元逐步线性回归显示：糖尿病病程、冠心病史与血浆AGEs浓度之间有线性关系。结论血浆AGEs浓度是糖尿病发生并发症的独立危险因素。     

Non-immune therapy of IgA glomerulonephritis

Summary: The involvement of the IgA immune system and complement components in IgA glomerulonephritis (IgAGN) has prompted the use of immunosuppressive drugs in therapy, but none has so far been shown to alter the natural course of the disease. Because most patients with IgAGN present during the chronic phase of their illness, at the time when the initiating immune events may no longer be active, nonimmune therapy which targets the common pathway of progressive renal injury is likely to be more useful. There is increasing evidence that angiotensin-converting enzyme inhibitors (ACEI) reduce proteinuria and renal injury in patients with IgAGN, and this effect may be observed in both normotensive and hypertensive patients. Yet to be determined is whether this effect is specific for ACEI and whatever other effective antihypertensive drugs may achieve a similar result. Fish oil has recently been shown to retard the progression of renal failure in patients with aggressive IgAGN, but a narrow therapeutic window appears to exist for this form of treatment. Antiplatelet agents on their own appear to be ineffective but in combination with anticoagulation (low dose warfarin) have been shown to have an antiproteinuric effect and may preserve renal function in patients with progressive disease. Future directions of non-immune therapy of IgAGN include evaluation of the renoprotective effect of angiotensin II receptor antagonists, free-radical scavengers and antilipid drugs. More work should also be done to identify factors which put the patients at risk of developing progressive disease and which predict therapeutic response, as has been done recently with the identification of the deletion polymorphism of the angiotensin-converting enzyme gene as a marker of progressive disease and therapeutic response to ACEI in patients with IgAGN.     

Mechanisms of proteinuria in nephrotic humans

The glomerular capillary wall imposes a remarkably efficient barrier to the passage of proteins the size of albumin and larger. The development of heavy proteinuria signifies impairment of the function of this barrier. Because endogenous proteins of graded size are heterogeneous with respect to their molecular charge and undergo extensive tubular reabsorption, they are not useful for quantifying the extent of barrier dysfunction. An alternative approach is to determine the fractional clearance of uncharged and non-reabsorbable polymers of graded size. When combined with a hydrodynamic theory of solute transport through a heteroporous membrane, the intrinsic properties of healthy and diseased glomerular capillary walls can be inferred. This approach reveals the nephrotic range proteinuria that attends minimal change nephropathy to be associated with impairment of both the size- and charge-selective properties of glomerular capillary walls.     

伊那普利治疗糖尿病肾病的临床研究

目的评估伊那普利治疗糖尿病肾病(DN)的临床疗效 ,并探讨其作用机制。方法40例持续微量蛋白尿的非胰岛素依赖型糖尿病(NIDDM)患者随机分为常规治疗组(n=19)和伊那普利治疗组(n=21)。利用 131I -邻碘马尿酸钠测定有效肾血浆流量(ERPF) ;肾小球滤过率(GFR)以内生肌酐清除率表示 ;通过ELISA法测定尿微量蛋白 ,包括白蛋白(ALB)、转铁蛋白(TF)、视黄醇结合蛋白(RBP)和N -乙酰 - β氨基葡萄糖苷酶(NAG)。结果伊那普利治疗组增高的尿ALB、TF、RBP和NAG均显著下降 ;ERPF显著增加 ;增加的滤过分数(FF)显著减低。而常规治疗组这些参数无显著变化。结论伊那普利具有改善DN患者的肾小球血流动力学 ,保护肾小球和肾小管功能的作用     

Measuring oscillatory potentials: Fourier analysis

Studying the oscillatory potentials in diabetic retinopathy, the authors experienced several problems interpreting results of digital filtering. The main problem was the separation of the first potential from the a-wave, since their frequencies are within the same range. To improve the procedure of measuring implicit times and of calculating amplitudes, the filtering was started with a finite impulse response filter and followed by a fast Fourier transform. The power of the oscillatory potential was calculated by determining the dominant frequency in the Fourier transformed response and expressed in microwatts. A group of normal subjects was compared with a group of early diabetic retinopathy patients. It appears that even in pathological circumstances a quantitative expression of the oscillatory potential is possible.     

N-acetylcysteine prophylaxis significantly reduces the risk of radiocontrast-induced nephropathy: comprehensive meta-analysis.

The objectives of this study was to assess the overall effect of N-acetylcysteine (NAC) in preventing radiocontrast-induced nephropathy (RCIN) using all available data in the literature. RCIN is associated with increased morbidity and mortality. Existing randomized trials of NAC are small and show inconsistent results. Prior meta-analyses do not include data from the most current studies. We used standard search protocols to identify all published articles and abstracts of prospective trials using NAC with fluid hydration compared to hydration alone in patients with chronic renal insufficiency undergoing contrast procedures. A rise in serum creatinine by 0.5 mg/dl or 25% above baseline at 48-72 hr after contrast exposure was used as the primary outcome. We identified 14 trials of NAC with 1,584 patients published as full-text articles. Using a random-effects model, the use of oral NAC resulted in a significant reduction in the risk for developing RCIN (RR = 0.57; 95% CI = 0.37-0.84; P = 0.01). This finding did not significantly change in a fixed-effect model (RR = 0.55; 95% CI = 0.42-0.73) or when the data were reanalyzed using only randomized trials in all forms (i.e., articles and abstracts; RR = 0.67; 95% CI = 0.47-0.95). We identified only one important difference between the positive and the negative studies: the cumulative exposure to contrast media (174 vs. 152 ml). Metaregression did not show a significant relationship between contrast volume and the RR of developing RCIN (P > 0.10). In the trials showing benefit for NAC, the treated patients' postprocedure creatinine unexpectedly decreased by 0.21 mg/dl (95% CI = 0.33-0.08). Prophylaxis with NAC significantly reduces the risk for RCIN. The reasons for improvement in serum creatinine in patients treated with NAC are unclear, but may include improved renal blood flow due to NAC and/or vigorous hydration.     

P_(27)、PCNA与IgA肾病中医证型及病理类型的关系

目的 :运用免疫组化方法研究原发性IgA肾病患者肾组织中细胞周期调控蛋白P2 7(P2 7)、增殖细胞核抗原PCNA(PCNA)的表达 ,探讨两者与IgA肾病病理分级及其与中医证型之间的关系。 方法 :选择行肾穿刺活检的IgA肾病住院患者 5 2例 ,并按照中医辨证分型标准将其分为肺肾气虚证、脾肾阳虚证、肝肾阴虚证、气阴两虚证、血瘀证、湿热证六型。系膜增生的病理组织学分为 4级。运用免疫组化方法检测P2 7、PCNA的表达。结果 :(1)IgA肾病各个病理分级P2 7、PCNA的表达两两比较有统计学意义。显示随着系膜细胞增生的病理分级程度增高 ,PCNA的表达增高 ,而P2 7的表达则按相反方向进行。病理分级和P2 7、PCNA表达的等级相关性检验 (Spearman法 )显示 :P2 7的表达与病理类型呈非常显著负相关 ,而PCNA的表达与病理类型呈显著正相关。 (2 )IgA肾病三个中医证型的病理分级之间有统计学意义 ,其中气阴两虚证的病理分级比湿热证、肝肾阴虚证高 ,湿热证与肝肾阴虚证的病理分级之间无统计学意义。 (3)随着湿热→肝肾阴虚→气阴两虚的进展 ,P2 7的表达呈现出逐渐减少的趋势 ,而PCNA的表达呈现出逐渐增加的趋势。结论 :(1)P2 7、PCNA作为判断IgA肾病肾脏组织学损伤程度和预后的指标值得深入研究。 (2 )IgA肾病中医证型之间病理分     

大豆异黄酮对大鼠慢性移植肾肾病的防治作用

目的通过对肾移植大鼠的饮食营养干预，观察大豆异黄酮对慢性移植肾肾病的防治作用。方法选择近交系雄性Fisher（F344）大鼠作为供者，雄性Lewis（Lew）大鼠作为受者，采用显微外科技术制作肾移植模型。将受者随机分为三组，分别给予高异黄酮大豆蛋白饲料（HIS组）、低异黄酮大豆蛋白饲料（LIS组）或酪蛋白饲料（CAS组）。移植前和移植后第4、12和24周时检测血压，并收集受者的血和尿样，检测尿蛋白和血肌酐含量。24周时处死大鼠获取移植肾，行组织学和免疫组织化学检查。结果在移植后4周时，HIS组受者的尾动脉收缩压、24h尿蛋白含量和血肌酐浓度即低于LIS组和CAS组，但差异无统计学意义（P〉0．05）；移植后12周和24周时，HIS组的受者尾动脉收缩压、24h尿蛋白含量和血肌酐浓度均较LIS组和CAS组显著降低（P〈0．05）；移植后24周时，HIS组移植肾组织的间质纤维化和炎症、血管硬化、肾小球硬化和肾小管萎缩等慢性病变均较LIS组和CAS组为轻（P〈0．05）；HIS组移植肾组织中转化生长因子-β1（TGF-β1）的表达和分泌均较LIS组和CAS组为少（P〈0．05）。结论大豆异黄酮对移植肾功能和结构有保护作用，可作为一种防治慢性移植肾肾病的新方法。     

Long-term follow-up study of 268 diabetic patients undergoing haemodialysis, with special attention to visual acuity and heterogeneity

We studied the long-term outcome of 268 patients suffering fromdiabetic end-stage renal disease (DM-ESRD) treated with long-termhaemodialysis between 1978 and 1991, with special emphasis onvisual acuity as well as the heterogeneity of DM-ESRD The 50%patient survival on haemodialysis was 60 months. Visual disturbanceswere found in 73.1% (392/536) of eyes at the start of haemodialysis.Chronological assess ment of visual acuity demonstrated thestabilization of visual acuity and 87.1% (364/418) of eyes werestable, 4.8% (20/418) were improved, and 8.1% (34/418) wereaggravated in the long term respectively. The change of visualacuity was frequently seen in the short term, and rapid shiftsof body fluid to correct overhydration induced abrupt changesof glycaemic control as well as retraction of macular oedema.Hence it might be one of the factors affecting rapid changeof visual acuity in the short term. Meanwhile, long-term deterioration of visual acuity resulted from either hyperten sionunresponsive to medical treatment or poor glycaemic control.Some DM-ESRD patients had only background retinopathy at thestart of haemodialysis and these were likely to have the nephroscleroticglomerular lesion. They were old, not nephrotic and had a milddegree of diabetes during the predialysis stage. Thus, DM-ESRDpatients seem to have some heterogeneity in their clinical characteristics,and old DM-ESRD patients with only background retinopathy havethe appearance of diabetic macroangiopathy rather than microangiopathy.