Biomedical subjects

Keiichi Yoshimoto

Publications and source records attributed to Keiichi Yoshimoto.

10 recordsLinked to original sources

PubMed2005

Involvement of extracellular signal-regulated kinase and p38 in human diabetic nephropathy.

BACKGROUND: The involvement of mitogen-activated protein kinase (MAPK) in human diabetic nephropathy has not been fully investigated. METHODS: The presence of cells positive for the phosphorylated MAPK family (phosphorylated extracellular signal-regulated kinase [p-ERK], phosphorylated p38MAPK [p-p38MAPK]) was investigated immunohistochemically in kidneys of 30 patients with diabetic nephropathy. In addition, 10 patients with minimal change nephrotic syndrome, 10 patients with thin basement membrane disease, and 5 patients with benign nephrosclerosis were studied as disease controls. The presence of activated nuclear factor-kappaB (p65)-positive cells also was evaluated in kidney specimens. RESULTS: In patients with diabetic nephropathy, p-ERK, p-p38MAPK, and p65 were observed in mesangial cells, endothelial cells, podocytes, tubular epithelial cells, and mononuclear infiltrates in interstitium. Numbers of p-ERK-, p-p38MAPK-, and p65-positive cells in both glomeruli and interstitium in patients with diabetic nephropathy were higher than those in controls. In particular, the number of glomerular p-ERK-positive cells in patients with diabetic nephropathy increased in accordance with the progression of glomerular lesions and correlated well with the number of glomerular p65-positive cells (r = 0.654; P < 0.01; n = 30). Conversely, the number of p-p38MAPK-positive cells in glomeruli did not correlate with glomerular lesions. However, the number of tubulointerstitial p-p38MAPK-positive cells in patients with diabetic nephropathy reflected the severity of tubulointerstitial lesions, and numbers of those in the interstitium increased with good correlation to numbers of tubulointerstitial p65-positive cells (r = 0.757; P < 0.01; n = 30) and interstitial CD68-positive macrophages (r = 0.647; P < 0.05; n = 30) and urinary monocyte chemoattractant protein-1 levels (r = 0.605; P < 0.05; n = 30). CONCLUSION: These results suggest that MAPK phosphorylation contributes to human diabetic nephropathy. In particular, ERK and p38MAPK may be distinctly involved in glomerular and tubulointerstitial lesions in human diabetic nephropathy.

Antigens, CD↗

PubMed2004

Pathologic findings of initial biopsies reflect the outcomes of membranous nephropathy.

BACKGROUND: A considerable diversity of prognosis is seen with idiopathic membranous nephropathy (IMN). The initial factors affecting long-term outcome remain unclear. METHODS: We studied retrospectively 105 patients with IMN who had been followed up for at least 5 years, or until end-stage renal failure (ESRF) (primary outcome), or death (secondary outcome). We analyzed the initial clinicopathologic factors affecting primary and secondary outcomes. We assigned the patients to two groups and one subgroup, based on the electron microscopic findings. The groupings were: homogeneous type with synchronous electron dense deposits; homogeneous type with large dense deposits (deep subgroup); and heterogeneous type with various phases of dense deposits. RESULTS: No differences in the initial clinicopathologic states were seen between the homogeneous (N= 60) and heterogeneous types (N= 45), apart from hypertension and disease history before biopsy. In the homogeneous type, only one patient developed ESRF, which was drug-induced, and remission occurred earlier than in the heterogeneous type. With regard to secondary outcomes, increased age, male gender, heterogeneous type, and deep subgroup were independent risk factors. There were no significant differences attributable to therapeutic regime with respect to primary or secondary outcome in either group. CONCLUSION: Our results indicate that an electron microscopic classification, at initial biopsy, as heterogeneous type or deep subgroup type with dense deposits are independent indicators of poor prognosis in IMN.

Adolescent↗

PubMed2004

The outcome and a new ISN/RPS 2003 classification of lupus nephritis in Japanese.

BACKGROUND: A considerable diversity in prognosis is seen with lupus glomerulonephritis (LGN). Hence, the clinical usefulness of a recent International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003 classification to judge the long-term outcome of human LGN has been investigated. METHODS: We studied retrospectively 60 subjects with LGN (7 males, 53 females, mean age of 33 years old) who underwent renal biopsies and were followed from 1 to 366 months, with a mean of 187 months. We diagnosed renal pathology as classes, active and sclerosing lesions, according to the new and WHO1995 classification of LGN, and analyzed the clinicopathologic factors affecting to the prognosis of LGN. RESULTS: New classification got much higher consensus in the judgment of classes (98% vs. 83%, P = 0.0084). The group of Class IV-S (N = 6) or IV-G (N = 17) at initial biopsies showed higher rate of end-stage renal failure (ESRF) compared with that of Class I, II, III or V (40.9% vs. 2.6%, P < 0.001). The mean 50% renal survival time of Class IV was 189 +/- 29 months, and patients with Class IV-S tended to have a poorer prognosis (95 +/- 22 months for IV-S vs. 214 +/- 35 months for IV-G, P = 0.1495). Class IV was also selected as the most significant risk factor for ESRF by stepwise model (P = 0.002). In subanalysis for ESRF in Class IV (-S or -G), treatment including methylprednisolone pulse therapy was only selected as a significant improving factor for primary outcome (P = 0.034). In addition, activity index was the significant risk factor of death and/or ESRF after initial renal biopsies (P = 0.043). As for actuarial patient death during all follow-up periods, complications with anti-phospholipid syndrome or nephrotic syndrome were significant risk factors (P = 0.013, P = 0.041, respectively). CONCLUSION: New ISN/RPS 2003 classification provided beneficial pathologic information relevant to the long-term renal outcome and the optimal therapy preventing ESRF and/or death in patients with LGN.

Adolescent↗

PubMed2004

CD68 and MCP-1/CCR2 expression of initial biopsies reflect the outcomes of membranous nephropathy.

BACKGROUND: A considerable diversity of prognosis is seen with idiopathic membranous nephropathy (IMN). The initial factors affecting long-term outcome remain unclear. METHODS: We studied retrospectively 30 patients with IMN who had been followed up for at least 5 years, or until end-stage renal failure (ESRF). We analyzed the prognostic factors of ESRF in the first renal biopsies; these factors included presence of tubulointerstitial lesions and foam cells, as well as expression of CD68, monocyte chemoattractant protein-1 (MCP-1), its cognate receptor chemokine receptor 2 (CCR2) and alpha-smooth muscle actin. RESULTS: The patients who developed ESRF showed higher percentages of glomerular segmental sclerosis, interstitial MCP-1 expression, CCR2- or CD68-positive monocyte/macrophages and foam cells in the interstitium, and these proved on multivariate analysis to be independent risk factors for ESRF. Finally, ESRF was characterized by the presence of ten interstitial CD68-positive cells per visual field at 200x magnification (hazard ratio 4.096, CI 1.271-15.029, p < 0.001). CONCLUSIONS: Our results suggested that an interstitial infiltration of CD68-positive cells accompanied by MCP-1/CCR2 expression is the most significant indicator of ESRF in IMN.

Antigens, CD↗

PubMed2004

[Membranous nephropathy].

Membranous nephropathy (MN) is a frequent cause of nephrotic syndrome in adults. A considerable diversity of prognosis is seen with idiopathic MN. We overview the recent progress of clinicopathological research, especially the initial factors affecting the longterm outcome of idiopathic MN. We studied retrospectively 105 patients with idiopathic MN and could assign the patients to two different groups based on the electron microscopic (EM) findings. In the homogeneous type only one patient developed end-stage renal failure, and earlier remission occurred in this group. With regard to secondary outcome, increased age, focal segmental glomerular sclerosis, arteriolosclerosis, heterogeneous type of EM findings were independent risk factors. Our results suggest that a new EM classification at initial biopsy is an independent indicator of prognosis in human idiopathic MN.

Adult↗

PubMed2002

Electron-dense deposition patterns and the outcomes of idiopathic membranous nephropathy in Japanese.

A considerable diversity in prognosis is seen with membranous nephropathy (MN). In terms of pathological findings, the presence of tubulointerstitial lesions was emphasized as a poor prognostic factor. However, the glomerular factors affecting the long-term outcome of idiopathic human MN have remained unclear. We reviewed the initial clinicopathological factors affecting the primary and secondary outcomes in 105 patients with primary MN, as well as reviewing previous reports. Based on electron microscopic (EM) findings, we could divide patients into two subtypes and one subgroup; i.e., homogeneous type with a synchronous phase of electron-dense deposits, with large dense deposits (deep subgroup) and heterogeneous type with various phases of dense deposits. The homogeneous type showed no endstage renal failure, and had earlier remission as compared with the heterogeneous type. For the secondary outcome, heterogeneous type and deep subgroup were also independent risk factors. However, there was no significant difference in the final primary or secondary outcome for any treatment subgroups. These results indicated that our category of EM findings was a beneficial marker of the primary and secondary outcomes in MN; the homogeneous type of MN with synchronous phase of electron-dense deposits (except for the "deep" subgroup) had a good outcome.

Female↗

PubMed2002

The beneficial effects of lymphocytapheresis for treatment of nephrotic syndrome.

A considerable permeability factor (or factors) derived from circulating T cells has a crucial role in proteinuria of nephrotic syndrome (NS). We attempted to remove pathogenic T cells through lymphocytapheresis (LCAP) in 6 patients with primary NS, 2 patients with minimal change nephrotic syndrome (MCNS), 2 patients with focal segmental glomerulosclerosis (FSGS), 1 patient with membranous nephropathy (MN), and 1 patient with MN and FSGS using Cellsorba (Asahi Medical Co., Osaka, Japan). LCAP was performed 2 times in 2 consecutive weeks and was followed with corticosteroid therapy with or without cyclosporine A in 5 patients. Two patients with MCNS, 1 with FSGS, and 1 with MN and FSGS showed a dramatic decrease of proteinuria (-30% and -94%) in their urine protein/creatinine ratio. Three out of 4 patients had a complete or partial remission (proteinuria <1g/day) within 8 weeks following immunosuppressive therapy. During the LCAP, T cells, especially activated T cells, decreased significantly in the response group. The other 2 patients, 1 with FSGS and 1 with MN, however, had no response to LCAP and following immunosuppressive therapy or low-density lipoprotein apheresis and suffered from end-stage renal failure or death by pneumonia. These results suggested that LCAP might have a beneficial effect on the treatment of NS, especially MCNS and in some patients with FSGS, despite varying responses to LCAP and concomitant immunosuppressive therapy.

Adolescent↗

PubMed2002

Administration of FR167653, a new anti-inflammatory compound, prevents renal ischaemia/reperfusion injury in mice.

BACKGROUND: Various types of chemokines/cytokines play important roles in ischaemia/reperfusion injury in kidneys. However, the roles of p38 mitogen-activated protein kinase (MAPK) in the inflammatory processes of renal ischaemia/reperfusion injury remain to be investigated. We explored the effect of FR167653, a specific inhibitor of p38 MAPK, on renal ischaemia/reperfusion injury in mice. METHODS: The renal artery and vein of the left kidney were occluded with a vascular clamp for 60 min. FR167653 was injected 2 h before or 24 h after renal vessel clamp. Renal tissues were removed for pathological examination 4, 24 or 48 h after reperfusion. RESULTS: We observed a large number of infiltrated cells and marked acute tubular necrosis in outer medulla after renal ischaemia/reperfusion injury in mice. FR167653 significantly decreased cell infiltration into outer medulla, and the extent of acute tubular necrosis 24 and 48 h after reperfusion. FR167653 markedly decreased the transcription of interleukin-1beta, tumour necrosis factor-alpha, monocyte chemoattractant protein-1 and regulated upon activation, normal T cell expression and secreted in diseased kidneys. Moreover, FR167653 decreased the number of phosphorylated p38 MAPK-positive cells 4 h after reperfusion. CONCLUSION: These results suggest that FR167653 markedly ameliorated renal ischaemia/reperfusion injury, possibly by inhibiting cytokine/chemokine expression and consequent phosphorylation of p38 MAPK in renal tissue.

Animals↗

PubMed2002

p38 MAPK phosphorylation and NF-kappa B activation in human crescentic glomerulonephritis.

BACKGROUND: p38 mitogen-activated protein kinase (p38 MAPK) followed by the activation of NF-kappa B participates in the intracellular signal transduction and production of cytokines and chemokines. The pathophysiological roles of p38 MAPK and NF-kappa B in human glomerulonephritis, however, remain to be investigated. METHODS: We investigated the phosphorylated p38 MAPK (p-p38 MAPK) and activated NF-kappa B immunohistochemically in the kidneys of 34 patients with crescentic glomerulonephritis and 26 control patients with thin basement membrane disease and minimal change nephrotic syndrome. We also explored the co-localization of p-p38 MAPK with CCR5, the signal of which leads to p38 MAPK activation. Furthermore, urinary levels of MIP-1 alpha, the cognate ligand for CCR5, were determined by enzyme-linked immunosorbent assay. RESULTS: p-p38 MAPK-positive cells and activated NF-kappa B-positive cells were mainly detected in crescentic lesions, tubular epithelial cells, and interstitial mononuclear infiltrates. The number of p-p38 MAPK-positive cells in patients with crescentic glomerulonephritis was higher than that in control patients. The number of p-p38 MAPK-positive cells in glomeruli was well correlated with the percentage of cellular crescents, the number of CD68-positive cells, and urinary MIP-1 alpha levels. In addition, the number of activated NF-kappa B-positive cells was well correlated with the number of p-p38 MAPK-positive cells in glomeruli. Dual staining revealed that most of CCR5-positive cells were positive for p-p38 MAPK. Finally, p-p38 MAPK-positive cells and activated NF-kappa B-positive cells decreased during glucocorticoid therapy-induced convalescence. CONCLUSIONS: We conclude that the phosphorylation of p38 MAPK associated with the activation of NF-kappa B may be involved in the upregulation of intrarenal MIP-1 alpha and the utilization of CCR5 signalling, which may result in human crescentic glomerulonephritis.

Female↗

PubMed2000

A new anti-inflammatory compound, FR167653, ameliorates crescentic glomerulonephritis in Wistar-Kyoto rats.

The pathophysiologic effects of FR167653 were investigated in a model of crescentic glomerulonephritis induced by a small dose of nephrotoxic serum in Wistar-Kyoto rats. The rats developed crescentic glomerulonephritis by 6 d after the administration of serum. The subcutaneous administration of FR167653 (32 mg/kg) markedly decreased the severity of the renal damage. In a group of rats treated with FR167653 daily from day 0 to day 6, glomerular damage, including crescent formation and proteinuria, was virtually absent. FR167653 markedly decreased urinary levels of monocyte chemoattractant protein-1 (MCP-1). In addition, FR167653 reduced production of MCP-1 protein and transcripts in the diseased kidneys. In a group of rats for which treatment was initiated on day 3, shortly after the appearance of glomerular abnormalities, the progression of renal disease was appreciably retarded, with partial inhibition of MCP-1. In contrast, when rats were treated only on the first day, no beneficial effects were observed and severe proliferative and necrotizing glomerulonephritis, with crescent formation, was induced by day 6, with the upregulation of MCP-1. These results suggest that FR167653 may be effective against crescentic glomerulonephritis, possibly via the inhibition of MCP-1. In addition, there was marked reduction in renal injury even when FR167653 treatment was initiated after glomerular inflammation was established, suggesting that the therapeutic application of FR167653 may be clinically useful for human renal diseases.

Animals↗