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Y Yuzawa

Publications and source records attributed to Y Yuzawa.

At least 37 records · Page 2Linked to original sources
PubMed1997

Role of a sialyl Lewis(x)-like epitope selectively expressed on vascular endothelial cells in local skin inflammation of the rat.

The role of the inducible L-selectin ligand was studied in complement-dependent acute dermatitis in rats. Although mAbs against typical sialyl Lewis(x) (CSLEX-1 and SNH-3) did not react with skin venules, a sialyl Lewis(x)-like epitope defined by mAb 2H5 (2H5-Ag) was de novo expressed on the endothelial cells of skin venules in the area of inflammation. Expression of 2H5-Ag increased concomitantly with the progression of inflammation. 2H5-Ag was identified at the 75-, 150-, and 180-kDa bands when inflammatory skin tissue was analyzed by Western blotting. In contrast, P- and E-selectins were not detectable. The role of 2H5-Ag in this model was studied in in vitro and in vivo methods. First, 2H5 was i.v. injected 15 min before induction of dermatitis. 2H5 bound to skin venules and significantly reduced the neutrophil infiltration and plasma protein leakage. In contrast, CSLEX-1, mAb ARP2-4 (P-selectin blocker), or mAb ARE-5 (E-selectin blocker) had no effects. Second, adhesion of isolated rat neutrophils to the inflammatory skin section was inhibited significantly when the sections, but not neutrophils, were preincubated with 2H5. Third, fluorescein-labeled normal rat neutrophils were injected into a rat 10 h after induction of dermatitis. The number of labeled neutrophils infiltrated into the inflammatory site was reduced significantly when they were preincubated with HRL-3 (blocking mAb against rat L-selectin), but not with 2H5 or HRL-4 (nonblocking mAb against rat L-selectin). These data show that de novo expressed 2H5-Ag/L-selectin adhesion pathway contributes to the development of acute complement-dependent inflammation in the skin.

Animals↗
PubMed1997

The role of complement in the pathogenesis of tubulointerstitial lesions in rat mesangial proliferative glomerulonephritis.

Persistent proteinuria and tubulointerstitial lesions are important signs of progressive renal disease. The purpose of this study was to assess the role of complement in the development of tubulointerstitial lesions in rats with proteinuria due to primary glomerulonephritis. Mesangial proliferative glomerulonephritis was induced in mononephrectomized rats by intravenous injection of monoclonal antibody (mAb) 1-22-3 (Clin Exp Immunol 102: 181-185, 1995). As early as 24 h after the injection, proteinuria became evident, persisted throughout the observation period, and was associated with mesangial cell proliferation and tubulointerstitial lesions when examined at 7 and 14 d after mAb administration. Deposition of rat C3 and C5b-9 was observed at the luminal surface of proximal tubules and in cellular debris present in the tubular lumen (group I). Rats injected with mAb 1-22-3 and depleted of complement by injections of cobra venom factor starting at day 3 developed glomerulonephritis and proteinuria comparable to rats of group I, but complement deposition in the tubules and the tubulointerstitial lesions were markedly reduced (group II). Rats in group III were injected with mAb and, from day 3, with soluble complement receptor type 1, which became detectable at the luminal surface of proximal tubules and in the urine. Deposition of C5b-9 in tubular cells was not detectable, and the severity of tubulointerstitial lesions was reduced compared with rats in group I. These results indicate that, in this model of primary mesangial proliferative glomerulonephritis with proteinuria, the development of tubulointerstitial lesions is associated with activation of serum complement at the level of tubular brush border, and tubulointerstitial lesions can be reduced by inhibition of complement activity.

Animals↗
PubMed1995

Role of a rat membrane inhibitor of complement in anti-basement membrane antibody-induced renal injury.

In the kidneys of anti-glomerular basement membrane (anti-GBM) antibody disease, binding of antibodies to tubular basement membrane (TBM) is often observed. The present work was performed to explore the mechanisms of binding of anti-GBM antibodies to TBM in vivo with special reference to 5I2Ag, a rat membrane inhibitor of complement which regulates complement activation at C3 convertase level. To suppress functions of renal 5I2Ag, F(ab')2 fragment of 5I2 (a neutralizing mAb against 5I2Ag) was perfused in the left kidney and then blood circulation was restored. Mild proteinuria ( < 10 mg/16 hr) was observed during first several days. Five days later, there were tubulointerstitial injuries defined by tubular vimentin staining and leukocyte infiltration. Significant deposition of C3 was observed in the capillaries and in TBM. In rats intravenously injected with rabbit anti-rat GBM antibodies five minutes after kidney perfusion with 5I2, strong binding of rabbit IgG to TBM was observed at one and five days after injection. Although these rats showed mild proteinuria comparable to those perfused with 5I2 and those injected with normal rabbit serum, tubulointerstitial injury was significantly enhanced at Day 5. In contrast, rats perfused with irrelevant mAb and injected with anti-GBM antibodies did not show any significant binding of antibodies to TBM nor tubulointerstitial injury. Furthermore, rats which were made proteinuric by puromycin aminonucleoside and injected with anti-GBM antibodies did not show any significant binding of rabbit IgG to TBM. These results indicate that 5I2Ag, a rat membrane inhibitor of complement at the C3 convertase level, regulates vascular permeability in the living kidney, and that dysfunction or decreased expression of this molecule leads to increased accessibility of anti-GBM antibodies to TBM.

Albuminuria↗
PubMed1995

Tubulointerstitial injury induced in rats by a monoclonal antibody that inhibits function of a membrane inhibitor of complement.

The kidney widely expresses membrane-associated complement regulatory proteins (membrane inhibitors of complement). The aim of this work was to evaluate the roles of these molecules in rat kidneys in vivo. To suppress functions of rat membrane inhibitors of complement, two mAbs, 512 and 6D1, were used. 5I2 and 6D1 inhibit functions of membrane inhibitors of complement at C3 level (rat Crry/p65) and C8/9 level (rat CD59), respectively. F(ab')2 fragment of 5I2 or 6D1 was perfused in the left kidneys, and perfusate was discarded from the renal vein. After perfusion, the left kidneys were connected to systemic circulation. In rats perfused with 5I2, mouse IgG was found in glomeruli, peritubular capillaries, vascular bundles, and tubules 15 min after recirculation. Binding of C3 and C5b-9 was evident in these areas. 1 d after perfusion with 5I2, cast formation, dilatation of tubular lumen, and tubular cell degeneration were observed. At day 4 through day 7, significant mononuclear cell infiltration and proximal tubule damage were observed. These changes were completely prevented by complement depletion. Rats perfused with 6D1 showed the binding of mouse IgG in the similar areas as 5I2, but C3 or C5b-9 deposition was not observed. Rats perfused with 6D1 or vehicle only did not show any pathology in the left kidneys. These results suggest that rat Crry/p65 plays protective roles against spontaneously occurring indiscriminate attack to tubulointerstitial tissues by autologous complement and that rat Crry/p65 is one of the important factors to maintain normal integrity of the kidney in rats.

Animals↗
PubMed1995

Interaction of antibody with Forssman antigen in guinea pigs. A mechanism of adaptation to antibody- and complement-mediated injury.

Forssman antigen is a glycosphingolipid with antigenic specificity determined by extra-membrane haptenic sugars similar to blood group antigens and antigens that are the main barrier to xenogeneic organ transplantation. Herein, we describe the localization of Forssman antigen in guinea pig lungs and kidneys and the consequences of its interaction with antibodies in vitro and in vivo (Forssman reaction). Exposure of cultured guinea pig aortic endothelial cells to Forssman antibodies induced rapid redistribution of antigen-antibody complexes at the cell surface, followed by shedding that occurred by blebbing of plasma membrane as vesicles or fragments, and was associated with disappearance of antigen from the cell surface (antigenic modulation). Guinea pigs surviving frequent intravenous infections of increasing amounts of antibodies, for a total of 20 to 40 lethal doses, developed a partial or complete adaptation to generalized Forssman reaction, and adaptation was associated with partial or complete modulation of Forssman antigen at the surface of the pulmonary and, in minor degree, renal endothelial and epithelial cells. These findings support the hypothesis that modulation of endothelial carbohydrate antigens contributes to adaptation of highly vascularized organs exposed to tolerable levels of allo- or xenoantibodies.

Animals↗
PubMed1995

[Hypercalcemia is the most common manifestation of hyperparathyroidism].

Hypercalcemia accompanying with the elevation of parathyroid hormone (PTH) is critical for the differentiation of primary hyperparathyroidism (I HPT) from other diseases which show hypercalcemia. Recently, the reliable immunoassays for PTH especially for intact-PTH have been established and widely introduced in the clinical field. Marked development of cellular and molecular biology also contribute to the exploration of the mechanism of calcium/bone metabolism. The diagnosis of I HPT can be easily established in some patients by their typical clinical findings. Many of them, however, usually show asymptomatic hypercalcemia while some patients show normocalcemia. It is highly important to evaluate the parathyroid function precisely by several biochemical or hormonal parameters related to calcium metabolism for complete diagnosis and treatment.

Calcium↗
PubMed1994

Localization of the complement regulatory proteins in the normal human kidney.

The kidney is an organ where complement-mediated tissue injuries take place by various stimuli. To assess how the kidney is protected from the autologous complement attack, comparative localization of decay accelerating factor (DAF), membrane cofactor protein (MCP) and 20 kDa homologous restriction factor (HRF20) was studied in the normal human kidney. Specific monoclonal antibodies to DAF, MCP and HRF20 were used for the study. Studies by immunofluorescence and immunoelectron microscopy showed that the distribution of each protein in the kidney was complementary to each other in most parts. MCP and HRF20 were clearly seen in the glomerular capillaries, while DAF was only faintly observed. Juxtaglomerular apparatus was abundant in DAF and MCP but not in HRF20. HRF20 was most strongly expressed in the peritubular capillaries where MCP was not detectable. Basolateral membranes of the proximal tubules and collecting ducts expressed MCP strongly, while there was no expression of DAF in the proximal tubules. Interestingly, both DAF and MCP, which inhibit complement activation at C3/C4 level, were not expressed in the apical portion of the tubular cells including proximal tubule brush border. In contrast, HRF20 was expressed on the apical part of the tubules. Medullary interstitium strongly expressed MCP but not DAF. Based on these observations, we conclude that each segment of the kidney is protected from the complement attack by the different combination of complement regulatory proteins. We speculate that the tubular cells might be fragile when complements are activated inside the tubular lumen, because there is no expression of complement regulatory proteins which inhibit C3 convertase.

Antibodies, Monoclonal↗
PubMed1994

Identification of risk factors on secondary hyperparathyroidism undergoing long-term haemodialysis with vitamin D3.

In order to evaluate the clinical outcome as well as the effect of vitamin D3 treatment on secondary hyperparathyroidism (SHPT) in the patients undergoing long-term dialysis therapy, we conducted a long-term follow-up survey on the demographic characteristics of 425 patients who were observed for more than 3 years. All patients were treated with daily 1 alpha (OH)D3 treatment after the initiation of dialysis. Among them the percentage of patients needing parathyroidectomy was 4.9%; aggravation of SHPT, 11.8%; an increase of the parathyroid hormone (PTH) level without radiographical abnormalities, 17.4%; stable, 56.2%; and a decrease of the PTH level, 9.7% at the final observation. The average PTH levels increased year by year irrespective of the difference of original renal disease. Gender, age at the start of dialysis, original renal disease, duration of dialysis treatment, the decade of starting dialysis, the degree of phosphate control, and the PTH level at starting dialysis were analysed as potential risk factors for SHPT, and assessed by multivariate analysis. Multivariate analysis revealed that only the terms of duration of dialysis and the PTH level at starting dialysis were the significant risks for developing overt SHPT. Logistic regression analysis revealed that the relative risk was significantly higher in the patients with more than 10 years history of dialysis and in those with the carboxyterminal PTH levels at the start of dialysis being more than 5 ng/ml. These results suggest that the treatment with daily low-dose vitamin D3 administration after dialysis initiation is imperfect; therefore some prophylactic therapy from the predialysis stage is necessary to prevent overt SHPT, which will occur after long-term haemodialysis.

Adolescent↗
PubMed1994

A case of renal sarcoidosis showing central necrosis and abnormal expression of angiotensin converting enzyme in the granuloma.

We describe a 66-year-old man who developed renal failure related to granulomatous renal sarcoidosis without systemic manifestations. Renal failure was severe enough to require hemodialysis transiently. Renal biopsy of this patient revealed the central necrosis of the granuloma which is usually absent in sarcoid granuloma. Serum level of angiotensin converting enzyme (ACE) was not helpful for diagnosis in this patient because serum ACE level is often elevated in the condition of chronic renal failure. Immunohistochemical detection of ACE was of diagnostic value in this patient. Subsequent course in which glucocorticoid was used for therapy was consistent with the diagnosis. This is the first report of identification of ACE in renal sarcoid granuloma.

Aged↗
PubMed1993

Antibody-mediated redistribution and shedding of endothelial antigens in the rabbit.

We report the results of studies performed in vitro and in vivo that were designed to explore individual, sequential, and concurrent Ag-antibody interactions at the surface of rabbit endothelial cells. Divalent heterologous antibodies to rabbit lung angiotensin-converting enzyme and to rabbit lung thrombomodulin were employed. In cultured monolayers, both antibodies redistributed the specific Ag and co-redistributed the immunologically unrelated Ag inducing partial or complete disappearance of the Ag from the cell surface (antigenic modulation) in 15 to 60 min. When injected into living rabbits, each antibody induced a rapid (1 to 3 min) redistribution and subsequent modulation of the specific and of the unrelated Ag at the surface of alveolar endothelial cells. Immune complexes, and the unrelated Ag, were shed in the circulation, attaining peak levels 3 to 4 min after the injection; were rapidly bound by platelets, E, and polymorphonuclear leukocytes; and were subsequently found in phagocytic cells in the spleen and in the liver. Thrombomodulin co-shed by angiotensin-converting enzyme antibody and, to a lesser degree, angiotensin-converting enzyme co-shed by thrombomodulin antibody, crossed the glomerular capillary walls and were reabsorbed by the epithelial cells of the proximal tubules within 2 to 3 min. The results show that immunologically unrelated Ag can be passively entrapped during formation of immune complexes at the cell surface, and provide new information on the kinetics of clearance of immune complexes containing endogenous, structural Ag.

Animals↗
PubMed1993

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 from diabetic end-stage renal disease (DM-ESRD) treated with long-term haemodialysis between 1978 and 1991, with special emphasis on visual acuity as well as the heterogeneity of DM-ESRD. The 50% patient survival on haemodialysis was 60 months. Visual disturbances were found in 73.1% (392/536) of eyes at the start of haemodialysis. Chronological assessment of visual acuity demonstrated the stabilization of visual acuity and 87.1% (364/418) of eyes were stable, 4.8% (20/418) were improved, and 8.1% (34/418) were aggravated in the long term respectively. The change of visual acuity was frequently seen in the short term, and rapid shifts of body fluid to correct overhydration induced abrupt changes of glycaemic control as well as retraction of macular oedema. Hence it might be one of the factors affecting rapid change of visual acuity in the short term. Meanwhile, long-term deterioration of visual acuity resulted from either hypertension unresponsive to medical treatment or poor glycaemic control. Some DM-ESRD patients had only background retinopathy at the start of haemodialysis and these were likely to have the nephrosclerotic glomerular lesion. They were old, not nephrotic and had a mild degree of diabetes during the predialysis stage. Thus, DM-ESRD patients seem to have some heterogeneity in their clinical characteristics, and old DM-ESRD patients with only background retinopathy have the appearance of diabetic macroangiopathy rather than microangiopathy.

Adult↗
PubMed1993

Acute renal failure and degenerative tubular lesions associated with in situ formation of adenovirus immune complexes in a patient with allogeneic bone marrow transplantation.

We describe the development of acute renal failure and degenerative tubular lesions associated with local immune deposits in a patient with allogeneic bone marrow transplantation. A 21-year-old man with an acute myelocytic leukemia received a bone marrow graft from a cousin mismatched for a single HLA-DR locus antigen. Hemorrhagic cystitis due to adenovirus type 11 infection occurred 26 days after transplantation, and 17 days later the patients developed acute renal failure. A study of renal tissue obtained by needle biopsy showed degenerative and necrotic lesions, especially in the distal part of the nephron. By electron microscopy adenovirus type 11 particles were found in the nuclei of tubular cells and in cellular debris in tubular lumina. By immunofluorescence technique, granular immune deposits containing adenovirus type 11 related antigen(s), immunoglobulins, C3, and membrane attack complex (MAC) C5b-9 of the complement system were detected along the tubular basement membranes but not in glomeruli. The patient's IgG did not bind to normal human kidneys. These findings suggest that adenovirus type 11 directly induced acute tubular damage, and that the tubular immune deposits were formed "in situ" by viral antigens and circulating viral antibody.

Acute Kidney Injury↗
PubMed1993

Nephrotic syndrome with massive accumulation of type I and type III collagen in the glomeruli.

A 54-year-old woman with nephrotic syndrome underwent renal biopsy. By light microscopy, the glomerular capillary lumen was remarkably narrowed because of diffuse accumulation of Periodic acid Shiff (PAS) positive material along the glomerular capillary wall. By electron microscopy, collagenous fibers were observed in the mesangium and subendothelial area. The fibrous material reacted with antibodies against type I and III collagen but not with those against laminin or type IV collagen by an indirect immunofluorescence technique. This case seemed to be a case of collagenofibrotic glomerulonephropathy.

Collagen↗
PubMed1993

Expression of interleukin 6 and major histocompatibility complex molecules in tubular epithelial cells of diseased human kidneys.

BACKGROUND: Interleukin-6 (IL-6) exerts multiple effects on infiltrated inflammatory cells and on structural cells in tissues. We previously reported that IL-6 expression is increased in the area of glomerular and tubular inflammation and tubular atrophy (Lab Invest 65:61, 1991). In the present study, we investigated the expression of IL-6 and HLA molecules in the tubules of patients with renal diseases, and correlate it with the morphological findings. EXPERIMENTAL DESIGN: Specific monoclonal antibodies and indirect immunofluorescence microscopy were used to identify IL-6, HLA-ABC, and -DR molecules, CD-2+ and CD-8+ lymphocytes and macrophages, in renal tissues obtained by biopsy from 41 patients that were divided into three groups on the basis of clinical, functional, and histologic findings. Group 1 included 12 patients with signs of acute renal disease and prevalent acute tubulointerstitial lesions. Group 2 included 19 patients with signs of chronic renal disease and histologic lesions of glomerulo- and tubulointerstitial nephritis. Group 3 included 10 patients that developed an acute renal disease treated with corticosteroids. When the acute symptoms subsided and the renal biopsy was performed, lesions characteristic of chronic tubulointerstitial nephritis were found. RESULTS: IL-6 was localized in all or in some cells of injured proximal tubules, including atrophic tubules. In one-third of specimens, there was more IL-6 in tubular cells than in infiltrated cells. The strongest expression of IL-6, HLA-ABC, and DR molecules was found in group 1, and the weakest in group 3. In the area with tubulointerstitial lesions, tubular IL-6 colocalized with HLA-ABC. Colocalization of IL-6 and HLA-DR was more evident in tubulointerstitial lesions of patients in group 2. In both groups 1 and 2, the distribution of IL-6 was statistically correlated with that of HLA-ABC and with interstitial infiltration of inflammatory cells. In group 2, there was statistical correlation between the expression of IL-6 and HLA-DR. The expression of IL-6 and of HLA molecules decreased in group 3. CONCLUSIONS: These results suggest that tubular IL-6 may be involved in the pathogenesis of tubulointerstitial nephritis.

Fluorescent Antibody Technique↗