Studies on urinary gamma-glutamyl transpeptidase in nephrotic syndrome patients

(1) Variations in the levels of GGT were measured in urine specimens taken in the early morning in control and in 20 consecutive adult patients with uncomplicated nephrotic syndrome. (2) The urinary GGT activity was increased in all cases of nephrotic syndrome patients investigated with different etiology. (3) A significant correlation was found between urinary GGT activity and serum albumin (r = 0.727) but not with serum cholesterol (r = 0.129). (4) These findings suggest that enhanced excretion of urinary GGT may be stimulated by decreased albumin concentration or oncotic pressure but does not appear to be due to leakage from plasma. (5) A systematic study on urinary GGT showed that GGT activity was decreased to the upper limit of normal control values in nephrotic syndrome patients after remission.     

成人原发肾病综合征患者血尿酸与血脂代谢的关系

目的:研究成人原发肾病综合征(PNS)患者高尿酸血症的患病率及其与血脂代谢的关系。方法:将109例成人PNS患者根据其尿酸水平分为高尿酸血症组与血尿酸正常组,检测患者的血脂、血清脂蛋白、ALB及24小时尿蛋白定量,分析成人PNS患者高尿酸血症的患病率,比较高尿酸血症组与血尿酸正常组PNS患者的一般情况及血脂水平,并分析PNS患者血尿酸水平的相关因素。结果:成人PNS患者高尿酸血症的发病率为24.77%;高尿酸血症组患者TG及24小时尿蛋白定量水平明显高于血尿酸正常组(P0.01),两组患者TC、LDL-C、HDL-C、Apo AI及Apo B比较差异无统计学意义(P0.05);成人PNS患者血尿酸水平与TG及24小时尿蛋白定量水平呈正相关(r=0.350,P=0.001;r=0.533,P=0.014),与TC、LDL-C、HDL-C及ALB无明显相关性(P0.05)。结论:成人PNS患者高尿酸血症的发生率较高,高尿酸血症患者具有更高的TG及尿蛋白水平,且成人PNS患者血尿酸水平与TG及24小时尿蛋白定量具有相关性,应高度重视成人PNS患者的血尿酸水平。     

Increased glomerular atrial natriuretic peptide receptor affinity in experimental nephrotic syndrome.

Atrial natriuretic peptide (ANP) is a cardiac hormone with natriuretic and diuretic effects. To better define the ANP hormonal system in the nephrotic syndrome, a condition associated with renal sodium retention, we undertook a study of glomerular ANP receptors in rats with puromycin aminonucleoside-induced nephrotic syndrome and in pair-fed controls. Nephrotic rats had significantly decreased serum albumin and total protein and significantly increased serum cholesterol, triglycerides and 24 hour urinary protein excretion. Plasma level of atrial natriuretic peptide was similar in both groups of rats. Competition binding inhibition studies in isolated glomeruli demonstrated one binding site in both groups of rats. The density of ANP binding sites in isolated glomeruli was similar in nephrotic and pair-fed rats while the binding affinity was increased significantly in the nephrotic rats. This is the first study to demonstrate alterations in renal ANP receptors in the nephrotic syndrome. Further studies will be necessary to determine whether alterations in glomerular ANP receptors contribute to renal sodium retention in the nephrotic syndrome.     

Humoral components of immunological response in nephrotic syndrome

Serum and urine were collected from 58 patients with nephrotic syndrome. Immunoglobulins (IgA, IgG and IgM), complement (C3) and transferrin levels were measured by single radial immunodiffusion. The extent of glomerular injury was estimated by determining the selectivity of proteinuria. The relationship between the severity of glomerular damage and serum concentrations of immunoglobulins and complement was assessed. Higher IgM and lower IgG serum concentrations were found in nephrotic patients than in normal controls (157 +/- 108 mg+ vs 127 +/- 38 mg% for IgM, 929 +/- 537 mg% for IgG). The difference was statistically significant (p less than 0.05 for IgM, p less than 0.001 for IgG). No correlation was present between the selectivity of proteinuria and serum levels of IgA, IgM, IgG or C3. The results indicate that abnormalities in humoral components of the immune system are present in nephrotic patients and are probably related to a basic immunological defect in the patients rather than to the severity of glomerular damage.     

In vivo platelet activity and serum albumin concentration in nephrotic syndrome

To clarify the relationship between serum albumin concentration and in vivo platelet activity in nephrotic syndrome, Beta-thromboglobulin (B-TG) levels and circulating platelet aggregation ratio (PAR) were determined in 25 nephrotic patients. PAR levels were significantly decreased compared with the controls and showed a positive correlation with serum albumin concentrations. The values of B-TG were high in all nephrotic patients and showed an inverse relationship with serum albumin levels. In addition, increased B-TG levels correlated with decreased PAR values. Therefore serum albumin plays a regulatory role in the activity of circulating platelets in the nephrotic syndrome. Prospective longitudinal studies must be done to elucidate the usefulness of platelet inhibitors as a prophylactic therapy of intravascular thrombosis in nephrotic patients.     

Profound urinary protein loss and acute renal failure caused by cyclooxygenase-2 inhibitor

Cumulative evidence has shown that nonsteroidal anti-inflammatory drugs (NSAIDs) can induce acute renal failure and nephrotic-range proteinuria. Cyclooxygenase-2 (COX-2) inhibitors have less nephrotoxicity; however, recent data indicate that they may cause the same renal problems as NSAIDs do. Herein, we present a case of celecoxib-associated minimal change disease (MCD) with profound urinary protein loss and acute renal failure. Renal function and nephrotic syndrome in this patient resolved completely after discontinuation of celecoxib and treatment with methylprednisolone. Clinicians should keep high index of suspicions in patients developing nephrotic syndrome and acute renal failure after taking COX-2 inhibitors since secondary MCD responds well to timely cessation of COX-2 inhibitors and administration of steroid therapy.     

An unusual case of Waldenstr?m macroglobulinemia with half molecules of IgG in serum and urine

Immunochemical studies are described in an unusual case of Waldenstr?m's macroglobulinemia. Two monoclonal Igs (whole IgG1/kappa and IgG1/kappa half molecules) occurred in the serum in addition to the IgM monoclonal protein. Protein electrophoresis of the serum showed a monoclonal component in the gamma region, and the immunoelectrophoresis allowed detection of a monoclonal IgM/kappa and another abnormality represented by a double precipitin line in serum and urine, observed when antiserum anti IgG was used. The abnormal proteins were purified and further analyzed. The IgG-related proteins were whole four chains IgG monoclonal molecules, 1/2 IgG monoclonal molecules, composed of one heavy and one light chain, and residual polyclonal IgG. The half molecules were antigenically deficient with respect to normal IgG. The idiotypic analysis showed that the three monoclonal proteins shared idiotypic determinants. This patient had clinical and morphological findings of Waldenstr?m's macroglobulinemia and, as observed in other cases, the formation of half molecules was not associated with a distinct clinical syndrome.     

Trypanostatic activity of rat IgG purified from the surface coat of Trypanosoma lewisi

Host IgG is a component of the surface coat of Trypanosoma lewisi; it is specifically acquired during infection in the rat, concomitant with a rise in titer of trypanostatic (ablastic) activity of host serum. Host IgG was eluted from trypomastigotes at 7 to 9 days postinfection with a high salt-low pH buffer. Surface coats and trypanosome ultrastructure were not notably altered by the elution procedure, as determined by electron microscopy. Rat IgG was removed and purified from the trypanosome eluates on an immunoadsorbent column made with the IgG fraction of anti-rat IgG serum coupled to Sepharose beads. Concentrated column eluates, by comparison with a standard, were shown to be rat IgG by immunoelectrophoresis and SDS polyacrylamide gel electrophoresis. As a control, IgG from normal rat serum was purified by the same technique. IgG-negative trypanosomes harvested from immunosuppressed rats bound IgG purified from surface coats of trypanosomes, but not IgG purified from normal rat serum, as demonstrated by subsequent labelling with FITC-conjugated, rabbit anti-rat IgG. The IgG purified from surface coats inhibited the reproduction of T. lewisi in an in vitro assay, but purified, normal IgG did not. These data show that antigen-specific host IgG, adsorbed to the surface of T. lewisi, is ablastic antibody.     

两种果子狸血清IgG纯化方法 的比较

目的 探讨一种具有简便快捷、高纯度、活性好的果子狸血清IgG纯化方法。方法 比较Hitrap Protein A亲和层析和PAGE电泳两种纯化法对果子狸血清IgG的纯化,用PAGE还原电泳和Western-Blot法对IgG作纯度鉴定。结果 对Hitrap Protein A纯化的果子狸血清IgG,其活性虽好,但纯度不高;而非还原PAGE电泳所纯化的果子狸血清IgG不但纯度高（〉95%）、并具有较强的免疫活性。结论 非还原PAGE电泳法纯化果子狸血清IgG,是一种具有高纯度、免疫活性强的纯化方法 。     

儿童激素耐药型肾病综合征合并星形诺卡菌脑脓肿1例

本文报道1例激素耐药型肾病综合征儿童合并星形诺卡菌(Nocardia asteroides,N.asteroides)脑脓肿。患儿,男性,8岁,临床诊断为原发性肾病综合征(激素耐药型),病理诊断为局灶节段性肾小球硬化症(经典型)。肾穿后第4天患儿出现持续高热、抽搐,时有头痛,抗感染、抗凝治疗效果不佳。复查颅脑磁共振成像(magnetic resonance imaging,MRI)提示多发脑脓肿。头颅脓肿液经穿刺后培养显示为星形诺卡菌感染。予以多种抗生素联合糖皮质激素等治疗2个月,患儿体温正常,头痛缓解,脑脓肿范围明显缩小。因此,肾病综合征患儿在应用激素及免疫抑制剂治疗过程中如出现化脓性炎症,常规抗生素疗效差,应积极寻找病原,高度警惕诺卡菌病及其他机会性感染的可能。     

Serum malondialdehyde levels,myeloperoxidase and catalase activities in patients with nephrotic syndrome

Abstract

Objectives

Some studies have indicated the pathophysiological importance of reactive oxygen species (ROS) in patients with nephrotic syndrome. Myeloperoxidase (MPO) is a leukocyte-derived enzyme-generating ROS that has been proposed to exert a wide array of pro-atherogenic effects throughout all stages of the atherosclerotic process. The aim of this study was to investigate the serum malondialdehyde (MDA) levels, MPO and catalase activities in patients with adult nephrotic syndrome.

Patients and Methods

Twenty-four patients with nephrotic syndrome and 24 healthy controls were enrolled. Serum MPO activity, catalase activity, and MDA levels were assessed.

Results

Serum MPO activity and MDA levels were signi?cantly higher in patients with nephrotic syndrome than controls (both, P < 0.001), while catalase activity was signi?cantly lower (P < 0.001). Serum catalase activity was found to be significantly correlated with MPO activity (r = ?0.417, P = 0.003) and MDA levels (r = ?0.532, P = 0.007). The serum MDA levels were also found to be significantly correlated with MPO activity (r = 0.419, P = 0.003).

Conclusions

We concluded that serum MPO activity and oxidative stress were increased and that serum catalase activity was decreased in patients with adult nephrotic syndrome. In addition, these results indicate that increased MPO activity is associated with an oxidant–antioxidant imbalance that may contribute to atherosclerosis in patients with adult nephrotic syndrome.     

Human anti-Pseudomonas aeruginosa outer membrane proteins IgG cross-protective against infection with heterologous immunotype strains of P. aeruginosa.

In order to develop an effective means to treat and prevent Pseudomonas aeruginosa infections, we have purified P. aeruginosa outer membrane protein (Oprs)-specific human IgG antibody using a large-scale affinity column. In this study, we investigated the cross-protective activity of the purified anti-Oprs IgG against various immunotype strains of P. aeruginosa. The anti-Oprs IgG reacted with Oprs isolated from seven Fisher-Devlin immunotype strains of P. aeruginosa and was able to promote opsonophagocytic killing of all seven immunotype strains by human phagocytic cells. Administration of 500 microg anti-Oprs IgG to mice raised the LD50 of the P. aeruginosa strains by 8-250-fold, indicating the protective capacity against heterologous P. aeruginosa strains as well as homologous strains. In contrast, despite high titers against P. (aeruginosa Oprs, total serum IgG isolated from burn patient sera was no better than normal serum IgG in protecting mice from infection with P. aeruginosa. These data demonstrate that the affinity-purified human anti-Oprs IgG could afford protection against heterologous immunotype P. aeruginosa strains and provide a rationale to use anti-Oprs IgG as an adjunct for treatment of P. aeruginosa infections in humans.     

Cav2.1 Voltage-dependent Ca<Superscript>2+</Superscript> Channel Current is Inhibited by Serum from Select Patients with Guillain-Barré Syndrome

To investigate the pathophysiological mechanisms of immune-mediated peripheral neuropathies, we studied the effects of sera from patients with Guillain-Barré syndrome (GBS) on the Cav2.1 voltage-dependent calcium channel (VDCC) current in Purkinje cells. Using the whole-cell recording technique, Cav2.1 VDCC current was measured in cerebellar Purkinje cells in the presence of serum from GBS patients with acute motor axonal neuropathy (AMAN) or acute inflammatory demyelinating polyneuropathy (AIDP). The AMAN patient sera significantly inhibited the Cav2.1 VDCC current compared with healthy volunteer sera, and this inhibition was fully reversible by washing out the AMAN serum. Similarly, IgG purified from AMAN sera also inhibited the Cav2.1 VDCC current. However, the activation and inactivation kinetics of the Cav2.1 VDCC currents were not affected by serum from an AMAN patient. Moreover, the VDCC current of Purkinje cells was also inhibited by IgG anti-GM1 monoclonal antibody (anti-GM1 mAb). In an immunocytochemical study using double fluorescence staining, Purkinje cells were stained by monoclonal IgG anti-GM1 mAb. In contrast, AIDP patient and healthy volunteer sera did not affect the Cav2.1 VDCC current. These results suggest that in some case of GBS, particularly of AMAN patients with IgG anti-GM1 mAb, muscle weakness may be induced by dysfunction of Cav2.1 VDCC functioning at the motor nerve terminals. Special issue article in honor of Dr. George DeVries.     

长爪沙鼠IgG的纯化及抗血清的制备

目的 纯化长爪沙鼠血清IgG,制备兔抗长爪沙鼠IgG抗血清。方法 采用Hitrap Protein G亲和层析预装柱来纯化长爪沙鼠血清IgG;通过SDS-PAGE电泳和Western-Blotting免疫印迹法对长爪沙鼠血清IgG进行纯度鉴定,免疫兔子制备抗血清。结果 7 mL长爪沙鼠血清纯化得到11 mg IgG;电泳和免疫印迹测定,IgG纯度大于95%;用纯化的IgG作抗原制备了兔抗血清,免疫双扩散测定效价达1∶32。结论 建立了长爪沙鼠血清IgG的纯化方法,制备了长爪沙鼠IgG抗血清,证实长爪沙鼠血清IgG和Protein G具有较高的亲和性。     

An attempt to analyze various thyroid stimulators by the receptor assay using hTSH radioimmunoassay.

In an attempt to analyze thyroid stimulators in serum we developed an assay procedure using hTSH radioimmunoassay (RIA) in combination with receptor competition. The principle of this method is the determination by RIA of hTSH displaced by other thyroid stimulators from a thyroidal receptor preparation which previously bound unlabelled hTSH. Practically 4 microunits of hTSH were bound with human or bovine receptor, and then hTSH displaced by addition of test serum (0.1 ml) or samples dissolved in serum (0.1 ml) was measured by RIA. This assay can determine the thyroid stimulators other than hTSH in serum that has the displacement activity of 0.5-4.0 microunits of hTSH in the useful range, such as mU/ml level of bovine TSH or rat TSH. Cholera toxin that has the thyroid stimulating activity like TSH also showed the displacement of the bound hTSH. This assay is not applicable for the human serum with more than 5 microunits/ml of TSH, because the assay value is over estimated by the free hTSH derived from the test serum. On the other hand, eighteen sera with high LATS activity and 42 sera with negative LATS activity from patients with untreated hyperthyroidism did not show any displacement. This might be due to the lower binding activity of LATS with hTSH receptor or the lower sensitivity of this assay method. Although it is difficult to use this assay clinically because of its low sensitivity, increased TSH in animal serum can be determined by this assay. The principle of this method may be also useful for examining the receptor binding of other peptide hormone that can be determined by an RIA method.     

黑线毛足鼠和金仓鼠血清IgG的纯化及抗血清的制备

目的 纯化黑线毛足鼠和金仓鼠血清IgG,制备兔抗金仓鼠和黑线毛足鼠血清IgG的抗血清。方法 用Hitrap Protein G亲和层析纯化黑线毛足鼠和金仓鼠血清IgG,经SDS-PAGE电泳鉴定纯度,标准免疫方法免疫兔子制备抗血清。结果 黑线毛足鼠和金仓鼠血清IgG对protein G有很高的亲合性,用Hitrap Protein G亲和层析纯化,得到高纯度黑线毛足鼠和金仓鼠IgG,利用纯化的IgG作抗原制备了高效价的抗血清,免疫双扩散测定效价达1∶32和1∶16。结论 证实黑线毛足鼠和金仓鼠IgG和Protein G具有很高的亲和性,Protein G亲和层析是纯化黑线毛足鼠和金仓鼠IgG有效的方法之一,制备了黑线毛足鼠和金仓鼠IgG的抗血清。     

Protective effects of mesenchymal stromal cells on adriamycin-induced minimal change nephrotic syndrome in rats and possible mechanisms

Background aimsMinimal change nephrotic syndrome is the most frequent cause of nephrotic syndrome in childhood. Current treatment regimes, which include glucocorticoid hormones and immunosuppressive therapy, are effective and have fast response. However, because of the side effects, long treatment course, poor patient compliance and relapse, novel approaches for the disease are highly desired.MethodsThe adriamycin-induced nephrotic rat model was established. Rats were allocated to a model group, a prednisone group or mesenchymal stromal cell (MSC) group. Clinical parameters in each treatment group were determined at 2 weeks, 4 weeks and 8 weeks. The messenger RNA (mRNA) levels of synaptopodin, p21 and monocyte chemoattractant protein-1 were determined through the use of quantitative real-time–polymerase chain reaction. Protein levels were determined by means of Western blot or enzyme-linked immunosorbent assay. Podocytes were isolated and apoptotic rate after adriamycin with or without MSC treatment was analyzed by means of flow cytometry.ResultsMSC intervention improved renal function as assessed by urinary protein, blood creatinine and triglyceride levels. MSC intervention reduced adriamycin-induced renal tissue damage visualized by immunohistochemistry and light and electron microscopic analysis and reduced adriamycin-induced podocyte apoptosis. After MSC intervention, mRNA and protein levels of synaptopodin and p21 in renal cortex were significantly increased. MSCs also restored synaptopodin mRNA and protein expression in isolated podocytes. In addition, monocyte chemoattractant protein-1 mRNA in renal cortex and protein level in serum of the MSC treatment group were significantly decreased compared with that in the adriamycin-induced nephropathy model group.ConclusionsOur data indicate that MSCs could protect rats from adriamycin-induced minimal change nephrotic syndrome, and the protective effects of MSCs are mediated through multiple actions.     

虎血清免疫球蛋白（IgG）的纯化及纯度、活性鉴定

目的 建立高纯度、高活性的虎血清IgG纯化方法。方法 用饱和硫酸铵沉淀虎血清得到IgG粗品;结合Hitrap Protein A亲和层析预装柱及阴离子交换层析法对粗品IgG进一步分离纯化,采用PAGE电泳和Western-Blot免疫印迹法鉴定IgG纯度和免疫活性。结果 80 mL虎血清亲和纯化得到84 mg IgG,阴离子交换层析纯化得到30 mg虎的IgG纯品。结论 建立了简便快速、纯度高、活性好的虎血清IgG的分离纯化方法,为虎血清IgG二级抗体的制备提供了高纯度、活性好的一级抗体免疫原。     

Antibodies to meningococcal H.8 (Lip) antigen fail to show bactericidal activity

Purified H.8 (Lip) antigen was coupled to tresyl-activated Sepharose 4B and used in affinity columns to purify anti-Lip antibodies from convalescent patient sera and from immune rabbit sera. Affinity-purified anti-Lip antibodies isolated from two convalescent patient sera contained 1000 and 1280 ELISA units of antibody and included antibodies of IgG, IgA, and IgM isotypes. An anti-Lip mouse monoclonal ascites (2-1-CA2) had 28,400 ELISA units of antibody. Bactericidal assays were performed using three different case strains of Neisseria meningitidis group B, namely 44/76, 8532, and 8047. Neither preparation of purified human anti-Lip antibodies had detectable bactericidal activity against strains 44/76 and 8532, but one of the two had a titer of 1:4 against strain 8047. Anti-Lip antibodies that were purified from immune rabbit serum and contained 1600 ELISA units of anti-Lip antibodies also failed to show detectable bactericidal activity. The rabbits were immunized with purified Lip antigen and showed specific antibody levels of 2000-2200 units by ELISA, but even the unfractionated sera had little or no bactericidal activity against the test strains. The high titer mouse monoclonal ascites had no bactericidal activity against the test strains. The poor bactericidal activity associated with monoclonal and polyclonal antibodies to the Lip antigen suggest that in spite of other attractive properties it may not be useful as a meningococcal vaccine.     

Resistance of proteinuric rats to furosemide: Urinary drug protein binding as a determinant of drug effect

The effect of drug binding to urinary proteins on the diuretic response to furosemide was assessed in normal and nephrotic rats. Nephrosis was induced by treating Sprague-Dawley rats with puromycin aminonucleoside. Binding of furosemide to urinary proteins was found to range from 60 to 95% depending on the concentration of urinary protein. The diuretic response to furosemide reaching the renal tubular lumen was inversely correlated with the degree of proteinuria, a finding that was independent of serum protein concentration of glomerular filtration rate. These data suggest that the binding of furosemide to urinary protein decreases the diuretic effect of furosemide and that drug-protein interactions of this type may also be important in modulating the activity of other lumenally-active drugs or endogenous substances exhibiting a high degree of protein binding. The binding of furosemide to urinary protein may explain the refractoriness of some patients with proteinuria to this agent.