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A new shield-cuttable tunnel wall system has been developed. This system enables a shield tunnelling machine to break in or break out by directly cutting the launch or arrival part of the concrete wall of a vertical shaft with its cutter bits without performing prior ground improvement works and manual demolition. When this system is applied to a column-type diaphragm wall, H-shaped steel piles used as the reinforcement in the wall should be replaced by bit-cuttable mixed-in-place mortar piles reinforced with carbon fibre reinforced polymer (CFRP). In order to connect the grid CFRP reinforcement and the flange of H-shaped steel, a specially designed mechanical splice has been developed. Tension tests of the mechanical splices were carried out to investigate their mechanical behaviour. The mechanical splice was applied to the newest subway tunnel in Tokyo.

Pathologic remodeling of mesangial matrix after glomerular injury is the central biologic feature of glomerular scarring (sclerosis). Transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF)-BB have been implicated in the development of glomerular scarring in rat and human glomerulonephritis. To clarify molecular and cellular mechanisms involved in abnormal mesangial remodeling, this study focused on the role of alpha1beta1 integrin, a collagen/laminin receptor, in rat mesangial cells, using collagen gel contraction as an experimental model of in vivo collagen matrix remodeling and scar formation. In addition, the influence of TGF-beta and PDGF-BB on mesangial cell (MC)-mediated collagen gel contraction in association with the alpha1beta1 integrin expression was evaluated. Integrin function blocking studies using anti-alpha1, beta1 subunit antibodies indicated that MC-alpha1beta1 integrin is essentially required not only for collagen-dependent adhesion/migration, but also for gel contraction. Protein synthesis and mRNA analysis experiments demonstrated that TGF-beta, but not PDGF-BB, increases the expression of alpha1beta1 integrin in mesangial cells cultured on plastic surface and in collagen gels. The upregulation of alpha1beta1 integrin expression by TGF-beta correlated with increases in gel contraction and collagen-dependent adhesion but not migration of mesangial cells. On the other hand, PDGF-BB enhanced MC-mediated gel contraction and migration without affecting cell adhesion to collagen I. Growth factor-induced collagen-dependent adhesion, migration, and gel contraction were significantly attenuated by incubation with anti-alpha1, beta1 subunit antibodies. Thus, these data indicate that alpha1beta1 integrin-mediated collagen matrix remodeling can be modulated by TGF-beta and PDGF-BB via different mechanisms. Alpha1 integrin-mediated mesangial matrix remodeling induced by TGF-beta or PDGF-BB may be a pathogenic mechanism leading to glomerular scarring.

beta 1-integrins, a family of cell-surface receptors, mediate cell-matrix interactions that play a critical role in tissue development and tissue remodeling after injury. In this study, to clarify the importance of beta 1-integrins in human glomerulonephritis (GN), the relationship among the glomerular expression of beta 1-integrins, their ligand matrix components, alpha-smooth muscle actin (alpha-SM actin) as a marker of activated mesangial cells (MC), transforming growth factor-beta (TGF-beta), and glomerular cellularity in two normal kidneys, ten minimal change nephrotic syndrome, 23 immunoglobulin A (IgA) GN, 13 lupus GN, and four membranous GN kidneys were studied. Immunostaining was performed on frozen sections, using monoclonal anti-alpha-SM actin antibody and polyclonal antibodies against fibronectin, collagen type IV, laminin, each subunit of alpha 1 beta 1 (collagen/laminin receptor), alpha 5 beta 1 (fibronectin receptor) and TGF-beta. Quantitation of staining indicated that the glomerular expression of alpha 1 beta 1 and alpha 5 beta 1 integrins correlated with the mesangial amounts of their ligands, collagen type IV, laminin and fibronectin (P0.01), alpha-SM actin (P0.01), and TGF-beta (P0.01). In addition, a correlation was observed between an increased expression of alpha 1 beta 1 and alpha 5 beta 1 integrins and the degree of glomerular cell proliferation (P0.01). Double immunostaining showed that activated MC expressing alpha-SM actin strongly expressed alpha 1 beta 1 and alpha 5 beta 1 integrins, and these MC phenotypic alterations paralleled the level of glomerular TGF-beta staining (P0.01). In conclusion, enhanced expression of beta 1-integrins by activated MC may contribute to the pathological mesangial remodeling characterized by MC proliferation and matrix deposition in human GN. Increased glomerular TGF-beta appears to be involved in these MC phenotypic changes.

In order to identify a new cell surface antigen as a potential marker of renal epithelial cell injury, we produced a monoclonal antibody (Mab), 1F3, by immunizing mice with cultured human glomerular cells. Immunofluorescence (IF) and immunoelectron microscopy (IEM) studies demonstrated that 1F3-recognizing antigen (1F3 antigen) was strongly expressed on the cell surface of glomerular podocytes and very weakly on parietal epithelial cells. 1F3 antigen was not expressed in any other cells in the normal kidney. Immunoprecipitation analysis using metabolically labeled glomeruli revealed that 1F3 recognized a 125-kD protein under reducing conditions. IF studies of biopsy specimens from patients with a variety of glomerular and tubulointerstitial diseases showed that 1F3 antigen was almost negative in cellular crescents but was strongly expressed in fibrocellular crescents. When glomerular sclerosis appeared, the expression of 1F3 antigen decreased in sclerotic areas of glomeruli. 1F3 antigen became positive in atrophic tubules that were seen in diseased kidneys. Severity of tubular atrophy correlated well with the extent of tubular expression of 1F3 antigen. These results indicate that Mab, 1F3 marks phenotypic changes of renal epithelial cells under disease conditions and may be a useful marker for progressive kidney diseases.

小児期発症のループス腎炎18例 (WHO分類1型1例，II型9例，III型2例，IV型4例，V型2例) に対する治療成績を検討した。18例中，ステロイド剤単独12例，ステロイド剤と免疫抑制剤の併用5例で，他の1例はステロイド剤，免疫抑制剤の投与を行っていない。ステロイド治療に対する反応は良好であり，10年生存率100%，腎生存率100%であった。蛋白尿，血尿の悪化は各々2例，1例にみられたが，他の症例では改善が認められた。血清補体値は全例で改善あるいは正常化し，抗DNA抗体価も全て正常化した。治療後，再生検しえた5例のうち，3例に腎病変の改善を認めた。また，治療中にステロイド中断例が5例あったが，3例が再燃し，うち1例は死亡した。以上より，ループス腎炎では早期診断，早期治療が予後および腎病変の改善に重要であるが，一方，ステロイド維持療法の意義も大きく，治療の中断は予後を著しく悪化させることが明らかとなった。

特発性ネフローゼ症候群におけるキャリーオーバー症例の臨床的検討を行った。小児期に発症し，成人期に至るまで長期観察しえた症例21例中10例 (47.6%) に16歳以後の再発を認めた。うち2例 (9.5%) は20歳以後にも再発の治療を要し，1例 (4.7%) は18歳で血液透析に至った。キャリーオーバー群と長期寛解群との比較検討を行ったが，臨床像，検査所見，ステロイド反応性等には有意な差異は認めなかった。本疾患の予後は良好と思われたが，成人期での再発もあり長期にわたる注意深い経過観察が必要と考えられた。

A patient with myasthenia gravis developed nephrotic syndrome 3 years after thymectomy. The kidney biopsy specimen revealed mesangial proliferative glomerulonephritis with immune deposits. The glomerular mesangial cells and tubular epithelial cells were sensitive to alpha-bungarotoxin (alpha-BT), a ligand for nicotinic acetylcholine receptor (nAChR), and the binding was inhibited by native alpha-BT, as well as other nAChR ligands, nicotine and d-tubocurarine. In addition, FITC-alpha-BT-neuromuscular junction complexes could also bind to the mesangial cells, and preincubation with unlabeled nAChR inhibited the binding. These findings are consistent with the notion that both nAChR-like protein and anti-nAChR antibody are present in t he mesangial cells of the patient. Although the pathogenetic role of anti-nAChR antibody on the development of glomerulonephritis is unclear, the present observations provide an important insight into the autoimmune-mediated pathophysiological relationship between myasthenia gravis and mesangial proliferative glomerulonephritis.

Transforming growth factor-beta (TGF-beta) has been implicated in the pathogenesis of mesangial matrix (MM) accumulation in human and experimental glomerulonephritis. To clarify molecular mechanisms responsible for pathological MM deposition, we examined the effect of TGF-beta on the production of beta1 integrins and on adhesion function of rat mesangial cells (MC). In immunoprecipitation experiments using [35S]methionine-labeled MC, stimulation of MC with TGF-beta for 48 h resulted in an increase in the synthesis of alpha1beta1 (collagen/laminin receptor) and alpha5beta1 (fibronectin receptor) integrins accompanied by increases in the synthesis of their ligands, collagen type I (collagen I), and fibronectin. A time-dependent increase in beta1, alpha1 integrin subunit mRNA peaking 48 h after exposure to TGF-beta was shown by Northern blot analysis. After 48 h of treatment with TGF-beta, MC displayed significant increases in adhesion to fibronectin, collagen I, and laminin as compared to untreated MC. Anti-beta1 antiserum significantly inhibits MC adhesion to fibronectin, collagen I, and laminin. Anti-alpha1 subunit antibody very strongly inhibited adhesion to collagen I and laminin, but not to fibronectin. Synthetic peptides containing RGD sequences specifically blocked adhesion to fibronectin. These data suggest that TGF-beta may promote MM deposition by increasing MC synthesis of both matrix proteins and beta1 integrins which facilitate binding of these proteins to the MC surface and thus enhance their incorporation into MM.

Streptococcus mutans has been shown to share a polysaccharide (PS) antigen with S. pyogenes strains isolated from patients with acute poststreptococcal glomerulonephritis (PSGN), using a monoclonal antibody f-77 reactive with the PS. To investigate the pathogenetic role of the shared PS in PSNG, experimental nephritis was induced in animals. Rats were immunized thrice with heat-killed cells of S. mutans or S. pyogenes, followed by an intravenous injection of live cells of S. pyogenes. Histologic examination showed that both animal groups had comparable degrees of diffuse proliferative nephritis characterized by immune deposits. The shared PS antigen was detected in glomeruli of all nephritic rats by immunofluorescence using monoclonal antibody f-77. Furthermore, all nephritic rats had an elevated antibody titer to the shared PS antigen. These results suggest that prior sensitization (infections such as dental caries) to S. mutans modulates immune responses to subsequent S. pyogenes infections and induces immune-complex disease (PSGN) through the shared PS antigen.

A 5-year-old Japanese girl was affected with acute nephritis. The patient had hypo-complementaemia and an elevation of anti-streptolysin O with positive throat culture of Group A streptococci. Four weeks after onset of the disease, serum complement level returned to normal, but proteinuria increased into the nephrotic range with a deterioration in renal function. Four weeks after onset, light microscopy of a renal biopsy showed diffuse endocapillary proliferation, and immunofluoroscopy revealed predominant IgA deposition in the mesangium. Electron microscopy showed electron dense deposits in the mesangial and subendothelial area, but subepithelial deposits were not found in the glomeruli. Histological diagnosis was IgA nephropathy, while her clinico-serological features were typical of acute post-streptococcal glomerulonephritis These results suggest that in some patients, IgA nephropathy may be triggered by streptococcal infection and misdiagnosed as acute post-streptococcal glomerulonephritis if renal histological examinations are not done.

Dual effects of angiotensin II on the plasminogen/plasmin system in rat mesangial cells. Previous studies indicate that angiotensin II (Ang II) stimulates extracellular matrix synthesis through induction of transforming growth factor-β (TGF-β) expression. Here we investigate Ang II effects on the plasmin protease system. Plasmin both degrades extracellular matrix itself and activates metalloproteinases which then degrade collagens. Plasmin production is determined by the balance between plasminogen activators (PA) and their inhibitors (PAI-1,2). The data presented here indicate that Ang II treatment of mesangial cells in culture markedly increases PAI-1 gene transcription and PAI-1 mRNA levels but does not change the half life of PAI-1 mRNA. Increased PAI-1 protein was detected 24 hours after Ang II stimulation with a concomitant decrease of PA activity. To determine whether these effects were mediated by TGF-β, cells were coincubated with Ang II and neutralizing antibody to TGF-β. Induction of PAI-1 at four hours was not altered but the prolonged effect of Ang II on PAI-1 protein synthesis was markedly diminished. Thus, Ang II acts both through rapid, direct transcriptional up-regulation of the PAI-1 gene and through induction of TGF-β, providing sustained changes in the PAI-1/PA system, which would favor extracellular matrix accumulation by inhibiting turnover. These data provide further evidence that Ang II can act as a potent fibrogenic molecule independent of its effects on blood pressure.