Augmented production of chemokines (monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1alpha (MIP-1alpha) and MIP-1beta) in patients with systemic sclerosis: MCP-1 and MIP-1alpha may be involved in the development of pulmonary fibrosis.

To determine the role of chemokines in the pathogenesis of systemic sclerosis (SSc), we examined serum levels, spontaneous production by peripheral blood mononuclear cells (PBMC), and histological distribution in the affected skin, of MCP-1, MIP-1alpha and MIP-1beta in SSc patients. Serum levels of these chemokines were examined by ELISA in 58 patients with SSc and 20 normal controls. The levels of these chemokines in culture supernatants from PBMC were also measured by ELISA. Serum levels and spontaneous production levels by PBMC of MCP-1, MIP-1alpha, and MIP-1beta were significantly elevated in patients with SSc compared with normal controls. Elevated serum levels of MCP-1 and MIP-1alpha significantly correlated with the presence of pulmonary fibrosis. MCP-1 expression in the skin of SSc was immunohistochemically examined using anti-MCP-1 MoAb. MCP-1 was strongly expressed in the epidermis, inflammatory mononuclear cells, and vascular endothelial cells in the sclerotic skin of SSc patients, but not expressed in any control skin. Furthermore, the MCP-1 expression in inflammatory mononuclear cells and endothelial cells significantly correlated with earlier onset of SSc. Thus, MCP-1, MIP-1alpha and MIP-1beta may be involved in the disease process, possibly by augmenting leucocyte migration into the affected tissues in SSc. Furthermore, MCP-1 and MIP-1alpha may play an important role in the development of pulmonary fibrosis in SSc.     

Aberrant activation profile of cytokines and mitogen-activated protein kinases in type 2 diabetic patients with nephropathy

Cytokine-induced inflammation is involved in the pathogenesis of type 2 diabetes mellitus (DM). We investigated plasma concentrations and ex vivo production of cytokines and chemokines, and intracellular signalling molecules, mitogen-activated protein kinases (MAPK) in T helper (Th) cells and monocytes in 94 type 2 diabetic patients with or without nephropathy and 20 healthy controls. Plasma concentrations of inflammatory cytokines tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-18 and chemokine CCL2 in patients with diabetic nephropathy (DN) were significantly higher than control subjects, while IL-10, CXCL8, CXCL9, CXCL10 and adiponectin concentrations of DN were significantly higher than patients without diabetic nephropathy (NDN) and control subjects (all P < 0.05). Plasma concentrations of TNF-alpha, IL-6, IL-10, IL-18, CCL2, CXCL8, CXCL9, CXCL10 and adiponectin exhibited significant positive correlation with urine albumin : creatinine ratio in DN patients. The percentage increases of ex vivo production of IL-6, CXCL8, CXCL10, CCL2 and CCL5 upon TNF-alpha activation were significantly higher in both NDN and DN patients than controls (all P < 0.05). The percentage increases in IL-18-induced phosphorylation of extracellular signal-regulated kinase (ERK) in Th cells of NDN and DN were significantly higher than controls (P < 0.05), while the percentage increase in TNF-alpha-induced phosphorylation of p38 MAPK in monocytes and IL-18-induced phosphorylation of p38 MAPK in Th cells and monocytes were significantly higher in NDN patients than controls. These results confirmed that the aberrant production of inflammatory cytokines and chemokines and differential activation of MAPK in different leucocytes are the underlying immunopathological mechanisms of type 2 DM patients with DN.     

Cytokine and chemokine levels in systemic sclerosis: relationship with cutaneous and internal organ involvement

Systemic sclerosis (SSc) is a connective tissue disorder characterized by excessive collagen deposition in the skin and internal organs. Several cytokines and chemokines have been implicated in the induction of fibrosis, but a definitive relationship between specific cytokines and organ involvement has not been established yet. Serum samples, PBMC and T cell lines (TCL) obtained from 54 patients affected by SSc and 20 healthy donors (HD) were examined by ELISA for Interferon-gamma (IFN-gamma ), interleukin (IL)-4, IL-6, IL-10, IL-18, Transforming growth factor (TGF)-beta1, Tumour necrosis factor (TNF)-alpha, sCD30, Macrophage derived chemokine (MDC), Monocyte chemoattractant protein (MCP)-1, Macrophage inflammatory protein (MIP)-1alpha and Regulated on activation normal T-cell expressed and secreted (RANTES). In all the SSc serum samples, we found significantly increased levels of IL6, TNFalpha and MCP-1 but reduced amounts of gamma-IFN and MDC. IL6, IL10, IL18, MIP-1alpha and TNFalpha measured in supernatants from PHA-stimulated PBMC and IL6, MCP-1 and RANTES in supernatants from stimulated TCL were also increased in patients. MDC was decreased in all the biological SSc sources studied. TGF-beta1, IL10, and sCD30 were produced at a significantly lower level by SSc TCL. Serum IL6 and sCD30 levels were significantly increased in dc-SSc patients compared to lc-SSc as were levels of MCP-1 produced by PBMC and IL10 from TCL. We observed a strict relationship between pulmonary fibrosis and IL10, MCP-1 (both from TCL) and serum IL6. Kidney involvement was related to serum MCP-1 levels and IL18 production from PBMC. Oesophageal involvement correlated with MDC production from PBMC and IL10 synthesis by TCL. We showed that IL-6, IL-10, MDC and MCP-1 are variably associated with internal organ involvement and allow the discrimination between limited and diffuse forms of the disease.     

Inhibition of inflammation by pentosan polysulfate impedes the development and progression of severe diabetic nephropathy in aging C57B6 mice

Inflammation has a key role in diabetic nephropathy (DN) progression. Pentosan polysulfate (PPS) has been shown to decreases interstitial inflammation and glomerulosclerosis in 5/6 nephrectomized rats. Since PPS has an excellent long-term safety profile in interstitial cystitis treatment, and we recently found that old diabetic C57B6 mice develop DN characterized by extensive tubulointerstitial inflammatory lesions that mimics human DN, we examined the effect of PPS on old diabetic mice. We also examined the anti-inflammatory properties of PPS in renal cells in vitro. Diabetes was induced with streptozotocin in 18 months female (early aging) C57B6 mice. Mice were then randomized to receive oral PPS (25 mg/kg/day) or water for 4 months. The effect of PPS on NF-κB activation and on TNFα, high glucose or advanced glycation end products (AGEs) stimulated proinflammatory gene expression in renal cells was examined. We found that PPS treatment preserved renal function, significantly reduced albuminuria, and markedly decreased the severity of renal lesions, including tubulointerstitial inflammation. PPS also reduced upregulation of TNFα and proinflammatory genes in aging diabetic kidneys. Furthermore, PPS suppressed NF-κB, decreased the proinflammatory actions of TNFα, and decreased high glucose and AGEs stimulated MCP-1 production in vitro. Finally, PPS decreased TNFα-induced increase in albumin permeability in podocyte monolayers. In conclusion, PPS treatment largely prevents the development/progression of nephropathy in aging diabetic mice. As this may be mediated by suppression of TNFα, high glucose, and AGE-stimulated NF-κB activation and inflammation in vitro, the in vivo blockade of DN may be due to the anti-inflammatory properties of PPS.     

2型糖尿病肾病患者血清MCP-1、NF-κB水平变化及临床意义

目的观察2型糖尿病肾病(DN)患者血清单核细胞趋化蛋白-1(MCP-1)、核因子-κB(NF-κB)表达水平的变化,并探讨其临床意义。方法 76例2型DN患者根据尿白蛋白/尿肌酐(UAlb/UCR)分为早期DN组(n=27例)、临床DN组(n=25例)和晚期DN组(n=24例),检测3组血清MCP-1、NF-κB、血清肌酐(SCr)、尿素氮(BUN)、尿蛋白排泄率(UAER)表达水平,同期选择28例单纯2型糖尿病患者及30例门诊正常体检者作为对照组。结果各组在性别、年龄、腰臀比、身体质量指数(BMI)等各方面比较无显著差异性(P0.05);各组DN患者血清SCr、BUN、UAER、MCP-1、NF-κB表达水平均明显高于对照组和单纯糖尿病组(P0.05),且随着病情程度加重而显著性升高(P0.05);而对照组与单纯糖尿病组比较无显著差异性(P0.05);血清MCP-1和NF-κB表达水平分别与血清SCr、BUN、UAER表达水平呈显著正相关性关系(P0.05)。结论 NF-κB和MCP-1表达水平升高均参与了DN发生、发展过程,阻断NF-κB信号转导途径,进而下调MCP-1表达水平可明显延缓DN的发生、发展过程。     

MCP-1 and RANTES polymorphisms in Korean diabetic end-stage renal disease

Macrophage infiltration has been observed in the renal biopsy specimens of diabetic nephropathy (DN), and hyperglycemic state stimulates the renal expression of RANTES (regulated upon activation, normal T-cell expressed and secreted) and MCP- 1 (monocyte chemoattractant protein-1). Upregulation of RANTES and MCP-1 with infiltrating macrophages may play a crucial role in the development and progression of DN. Genetic polymorphisms of RANTES and its receptors were reported to be independent risk factors for DN. We genotyped single nucleotide polymorphism (SNPs) in the MCP-1 G-2518A, CCR2 G46295A, RANTES C-28G and G-403A in 177 diabetic end-stage renal disease (ESRD) patients and 184 patients without renal involvement (controls) in order to investigate the effects of these SNPs on DN in Korean patients with type 2 DM. There were no differences in the frequencies of SNPs and the distribution of haplotypes of RANTES promoter SNPs between two groups. In conclusion, there were no associations of MCP-1, CCR2 and RANTES promoter SNPs with diabetic ESRD in Korean population. Prospective studies with clearly-defined, homogenous cohorts are needed to confirm the effect of these genetic polymorphisms on DN.     

Immune response of tonsillar lymphocytes to Haemophilus parainfluenzae in patients with IgA nephropathy

The pathogenesis of IgA nephropathy (IgAN) is unclear. We have previously shown glomerular deposition of Haemophilus parainfluenzae (HPI) antigens and the presence of IgA antibody against HPI antigens in patients with IgAN. We examined the immune response to HPI antigens in tonsillar lymphocytes from patients with IgAN. Lymphocytes isolated from the palatine tonsils of 13 IgAN patients and 16 patients with chronic tonsillitis but without renal disease were used as controls. We examined lymphocyte proliferation and production of IgA antibody against HPI antigens by measuring thymidine uptake and IgA antibody in culture supernatants after lymphocyte incubation with HPI antigens. Patients with IgAN showed a significantly higher stimulation index to HPI antigens (thymidine incorporation in tonsillar lymphocytes with HPI/thymidine incorporation in unstimulated tonsillar lymphocytes) than controls (P < 0.002). Lymphocytes from patients with IgAN also showed a significantly higher level of IgA antibody and IgA1 antibody against HPI antigens in culture supernatants than lymphocytes from controls (P = 0.0002 and P = 0.004, respectively). Our results suggest that HPI antigens stimulate tonsillar T and B lymphocytes in patients with IgAN and that an immune response to HPI antigens may play a role in the pathogenesis of this disease in some cases.     

甲基四氢叶酸还原酶基因多态性与糖尿病肾病关系的研究

目的：探讨甲基四氢叶酸还原酶（methylenetetrahydrofolate reductase,MTHFR)基因多态性与糖尿病肾病（diabetic nephropathy,DN)发生的关系。方法：利用聚合酶链反应－限制性片段长度多态性分析法（PCR－RFLP）检测了85名健康人和经尿微量白蛋白检测确诊的82例合并DN和79例无DN的2型糖尿病患者MTHFR基因第677位碱基多态性。结果：DN患者MTHFR基因变异型纯合子和等位基因频率均明显高于无肾病患者及健康者,P＜0．01。结论：MTHFR基因第677位碱基变异可能是中国汉族人DN发生的一个遗传危险因子。     

血、尿IL-6变化在糖尿病肾病中的意义

目的 探讨血、尿IL-6变化在糖尿病肾病诊断治疗中的意义.方法 将实验对象分为观察组和对照组,观察组52人,对照组40人.根据尿白蛋白排泄率(UAER)将观察组又分为两个小组:分别为微量蛋白尿组DN1(24例)和临床蛋白尿组DN2(28例).对照组选取40名健康成年人.观察各组血、尿IL-6水平.结果 ①观察组病人血、...     

雷公藤多甙联合奥美沙坦脂治疗早中期糖尿病肾病的临床观察

目的观察雷公藤多甙治疗早中期糖尿病肾病（DN）的临床疗效。方法将80例早中期DN患者随机分为治疗组45例、对照组35例,两组患者均口服奥美沙坦脂。治疗组在此基础上加服雷公藤多甙。观察两组患者治疗前后尿白蛋白排泄率（UAER）、尿β2微球蛋白（β2-MG）、单核细胞趋化因子（MCP-1）、血清白蛋白（ALB）、血肌酐（SCr）和谷丙转氨酶（ALT）等指标变化。结果治疗组的总有效率为84.44%,对照组的总有效率为54.29%,治疗组的疗效较对照组好,差异有统计学意义（P〈0.01）。治疗后两组UAER、β2-MG和MCP-1水平较治疗前出现明显下降（P〈0.05或〈0.01）,但治疗组下降更为明显,与对照组比较差异有统计学意义（P〈0.01）。仅治疗组SCr较治疗前和对照组出现明显下降（P〈0.01）,而治疗组ALB水平较对照组和治疗前出现明显提高,差异有统计学意义（P〈0.01）。两组治疗前后的ALT水平差异无统计学意义（P〉0.05）。结论雷公藤多甙联合奥美沙坦酯治疗DN疗效显著,其机理可能与降低MCP-1水平有关,并且毒副作用较小。     

Increased expression of plasminogen activator inhibitor-1 in hypoxic renal injury and its pathological significance in progression of advanced renal disease

Chronic hypoxia has been newly proposed as a common mechanism of progressive renal fibrosis where PAI-1 plays important roles in the accumulation of extracellular matrix (ECM) through inhibition of plasmin-dependent ECM degradation. Hypoxia is also presumably associated with macrophage recruitment and angiogenesis that form fibrotic lesions. In the present study, we examined the effects of hypoxia and TNF-alpha on PAI-1, MCP-1 and VEGF expression in cultured human proximal renal tubular cells (HPTECs). We also investigated the presence of PAI-1 in renal tubular cells by immunostaining renal biopsy samples and measuring urinary PAI-1 levels in different kidney diseases. cDNA array analysis identified PAI-1 as a major gene highly induced by hypoxia in HPTECs. Hypoxia, TNF-alpha and their combination induced a 2.8-fold, a 1.8-fold, and a 4.6-fold increase in PAI-1 protein secretion, and produced a 3.6-fold, a 3.3-fold, and a 12.1-fold increase at the PAI-1 mRNA level, respectively. Similar results were confirmed by luciferase assay. Immunoblot analysis and immunocytochemistry revealed that hypoxia-inducible factor-1alpha (HIF-1alpha) was markedly accumulated in nuclei after 16-hours of hypoxia. Hypoxia reduced basal and TNF-alpha-stimulated MCP-1 expression, while it induced VEGF expression in HPTECs. In crescentic glomerulonephritis (CrGN) or diabetic nephropathy (DN) with severe proteinuria, clusters of proximal tubules and a part of the fibrotic interstitium were specifically stained for PAI-1, while no stainings were found in minor glomerular abnormality or minimal change nephrotic syndrome. Urinary PAI-1 levels were significantly higher in CrGN and DN than in healthy controls. In DN, urinary TNF-alpha levels were significantly correlated with urinary PAI-1 levels. PAI-1 induced by hypoxia and inflammation may contribute to further progression of advanced kidney disease, CrGN or DN. Hypoxia together with inflammation may also be involved in promotion of renal fibrosis in part by modulating MCP-1 and VEGF expression.     

Effect of interleukin-2 on peripheral blood mononuclear cell cytokine production and the hepatic acute phase protein response

This study investigated the ability of recombinant interleukin-2 (IL-2) to modulate the ability of peripheral blood mononuclear cells (PBMCs) to stimulate an acute phase protein response in isolated human hepatocytes. The effect of IL-2 on the production of tumour necrosis factor-alpha (TNF) and interleukin-6 (IL-6) by PBMCs isolated from patients with gastrointestinal cancer, multiple organ failure, and healthy controls was also studied. The ability of supernatants from IL-2-treated PBMCs to elicit an acute phase response in hepatocytes was then investigated. IL-2 had no effect on IL-6 or TNF production by PBMCs isolated from any group in the presence or absence of bacterial lipopolysaccharide (LPS). Despite this, preincubation of PBMCs with IL-2 significantly reduced the potential of LPS-stimulated PBMC supernatants to stimulate production of alpha1 antichymotrypsin, alpha1-acid glycoprotein, and C-reactive protein by hepatocytes. These observations were not due to a direct effect of IL-2 on hepatocyte acute phase protein production. These findings suggest that in this model IL-2 may modulate PBMC-induced acute phase protein production through an IL-6 and TNF-independent pathway.     

Effects of vitamin D on renal fibrosis in diabetic nephropathy model rats

This study is to investigate the effects of vitamin D on renal fibrosis in rat diabetic nephropathy models, as well as the changes and interactions in the expressions of renal fibrogenesis- and inflammation-related genes. Rat diabetic nephropathy models were established by high-fat diets, which were subjected to TGF-β1 manipulation, as well as vitamin D treatment. H&E staining, Masson staining, and TEM detection were performed to assess the effects of vitamin D treatment and/or TGF-β1 manipulation on pathological changes in the renal tissues in these rat diabetic nephropathy models. Immunohistology and real-time PCR were used to evaluate the expressions of TGF-β1, MCP-1, CTGF, and VDR. Histological staining and TEM detection showed that, in both TGF-β1 over-expressed and interfered groups, vitamin D administration alleviated the renal fibrosis, compared with the vehicle treatment. Similar results were observed with the immunohistological staining. Real-time PCR analysis indicated that, when TGF-β1 was over-expressed in diabetic nephropathy, the expressions of MCP-1 and CTGF were also up-regulated, which would be decreased by the treatment of vitamin D. On the other hand, when TGF-β1 was interfered in DN, the expressions of MCP-1 and CTGF were relatively down-regulated, which would be further lowered by vitamin D administration. The mRNA expression of VDR was elevated by vitamin D treatment in these diabetic nephropathy models. Active vitamin D₃ and lentivirus-mediated TGF-β1 interference could effectively reduce the renal fibrosis and protect the renal function in diabetic nephropathy rat models, which makes a promising therapeutic strategy for the disease.     

单核细胞趋化蛋白-1与糖尿病肾病

单核细胞趋化蛋白-1(MCP-1)是一种特异性趋化因子，在糖尿病肾病 (diabetic nephropathy，DN)的发生发展中起重要作用。代谢性因素如高糖（HG）、糖基化白蛋白（glycated albumin， Gly-Alb）、氧化应激，蛋白激酶C(protein kinase C，PKC)等和血流动力学因素如肾素-血管紧张素系统（RAS）等均可上调肾小球内皮细胞、系膜细胞 (mesangial cell，MC)、小管上皮细胞（tubulus epithelial cells，TECs）中MCP-1基因和蛋白的表达，使单核/巨噬细胞在肾组织中聚集，通过多种机制引起肾脏损伤。     

血管紧张素原基因M235T分子变异与型糖尿病肾病的关系

目的 探讨血管紧张素原ａｎｇｉｏｔｅｎｓｉｎｏｇｅｎ,ＡＧＴ）基因Ｍ２３５Ｔ分子变异与中国人无肾病并发症的２型糖尿病（ｄｉａｂｅｔｅｓ ｍｅｌｌｉｔｕｓ,ＤＭ）、２型糖尿病肾病（ｄｉａｂｅｔｉｃ ｎｅｐｈｒｏｐａｔｈｙ,ＤＮ）的关系。方法用ＰＣＲ及ＲＦＬＰ方法对８４例ＤＭ、９６例ＤＮ及９８名正常对照进行了ＡＧＴ基因Ｍ２３５Ｔ多态性的检测。结果 ＤＮ组Ｔ等位基因频率０．８２,ＴＴ基因型频率０．７０     

DN患者血清内脂素和脂联素检测的临床意义

目的：探讨2型糖尿病肾病（DN）患者血清内脂素和脂联素水平的变化及意义。方法：应用放射免疫分析和酶联法测定41例DM2无肾病组和32例DN组患者血清内脂素和脂联素水平,并与35名正常人作比较。结果：DM2患者无论有无肾病组其血清内脂素水平均显著地高于正常人组（P〈0.01）,血清脂联素水平显著低于正常人组（P〈0.01）,两者呈明显的负相关（r=-0.4108,P〈0.01）。DN组血清脂联素水平高于DM2组。结论：血清内脂素、脂联素水平与DN的发生与发展密切相关,有重要的临床价值。     

血管紧张素转换酶基因缺失纯合型与糖尿病肾病相关联

应用ＰＣＲ扩增方法检测２０３例ＮＩＤＤＭ患者和１６５例正常对照者血管紧张素（ＡＣＥ）基因的１６内含子中２８７ｂｐ片段缺失／插入多态性。结果显示,糖尿病肾病患者组ＡＣＥ基因缺失纯合型（ＤＤ）频率明显高于非肾病组和正常对照组,Ｐ〈０．００１;ＤＤ缺失纯合型患者肾病进展速度明显快于缺失／插入（ＤＩ）杂合型及插入／插入（ＩＩ）纯合型糖尿病患者,Ｐ〈０．０１。表明ＡＣＥ基因缺失纯合型是糖尿病肾病的独立危险因     

血管紧张素原基因M235T分子变异与2型糖尿病肾病的关系

目的　探讨血管紧张素原（ａｎｇｉｏｔｅｎｓｉｎｏｇｅｎ , Ａ Ｇ Ｔ） 基因 Ｍ２３５ Ｔ 分子变异与中国人无肾病并发症的２ 型糖尿病（ｄｉａｂｅｔｅｓ ｍ ｅｌｌｉｔｕｓ , Ｄ Ｍ） 、２ 型糖尿病肾病（ｄｉａｂｅｔｉｃ ｎｅｐｈｒｏｐａｔｈｙ , Ｄ Ｎ） 的关系。方法　用 Ｐ Ｃ Ｒ及 Ｒ Ｆ Ｌ Ｐ 方法对８４ 例 Ｄ Ｍ、９６ 例 Ｄ Ｎ 及９８ 名正常对照进行了 Ａ Ｇ Ｔ 基因 Ｍ２３５ Ｔ 多态性的检测。结果　 Ｄ Ｎ 组 Ｔ 等位基因频率０８２ , Ｔ Ｔ 基因型频率０７０ ,与对照组（０６３ ,０４３） 比较有显著差异（ Ｐ＝ ０００３ , Ｐ＝００００４） ;校正了 Ｄ Ｎ 的几种危险因素后, Ｔ Ｔ 基因型对 Ｄ Ｎ 的 Ｏ Ｒ 为３４７（９５ ％ Ｃ Ｉ 为１５１ ～７９４ , Ｐ＝０００３３） 。 Ｄ Ｍ 组基因型频率分布与对照组比较无显著差异（ Ｐ＞ ００５） 。结论　 Ａ Ｇ Ｔ 基因 Ｔ Ｔ 型可能是中国人群２ 型糖尿病肾病的独立危险因素之一。     

Immunofluorescence staining in unfixed or fixed renal biopsy specimens from patients with diabetic nephropathy

Immunofluorescence staining in unfixed or fixed renal biopsy specimens were evaluated in nine patients with diabetic nephropathy in order to elucidate if immunofluorescence staining is applicable in fixed renal tissues in such patients. Renal biopsy specimens were embedded in gelatin or paraffin matrix. Renal biopsy specimens embedded in paraffin matrix were digested with 0.05% protease. Immunofluorescent studies of kidney tissues were performed by staining with FITC-labeled heavy chain specific anti-human IgG, IgA, IgM, acute phase reactant (APR) proteins such as alpha 1-anti-trypsin (alpha 1-AT), haptoglobin (Hpt) and beta-lipoprotein (beta-Lp) antisera, and then examined with a fluorescent microscope. Linear and nodular deposition of IgG, IgA, IgM, alpha 1-AT, Hpt, and beta-Lp were observed in the glomerular capillary walls of the renal specimens embedded in paraffin matrix. The staining patterns in specimens embedded in paraffin matrix was similar to that embedded in gelatin matrix. There was no significant difference in the intensity or distribution of IgG, IgM, alpha 1-AT, and beta-Lp deposition among the two different conditions of immunofluorescence in patients with diabetic nephropathy. It was suggested that immunofluorescence staining in renal biopsy specimens embedded in paraffin matrix after digestion with protease is useful for the evaluation of IgG, IgM, APR proteins, and beta-Lp in glomeruli from patients with diabetic nephropathy.