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Biomedical subjects

J Usui

Publications and source records attributed to J Usui.

14 recordsLinked to original sources
PubMed2003

Glomerular crescents predominantly express cadherin-catenin complex in pauci-immune-type crescentic glomerulonephritis.

AIMS: To investigate the expression of the cadherin complex in human crescentic glomerulonephritis to elucidate the role of intercellular adherens junction molecules in crescent formation. METHODS AND RESULTS: Immunostaining revealed cadherin complexes localized in Bowman's epithelial cells, but not in podocytes, of normal human glomeruli. Eight adult cases with myeloperoxidase anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA)-related (pauci-immune type) crescentic glomerulonephritis were examined on immunofluorescence microscopy with anti-pan cadherin, p120 catenin, and beta-catenin antibodies. The specimens provided six cellular crescents, 12 fibrocellular crescents, and four fibrotic crescents. Immunofluorescence was semiquantitatively estimated by the rate of the field of localization within the whole area of the crescent, according to the four-grade system [(-) - (++)]. All the tested molecules consisting of the cadherin complex were abundantly observed in cytokeratin-positive epithelial components in crescents, each with an equivalent area of localization. The expression of the cadherin complex was closely associated with that of cytokeratin and both diminished as the crescents developed from cellular to fibrotic. CONCLUSIONS: The cadherin-catenin complex is a specific marker of Bowman's epithelial cells in human glomeruli. The cellular crescents in pauci-immune-type crescentic glomerulonephritis possess adherens junction molecules, indicating a principle parietal epithelial cell phenotype.

Adherens Junctions↗
PubMed2001

Heterogeneity of prognosis in adult IgA nephropathy, especially with mild proteinuria or mild histological features.

OBJECTIVE: The present study was undertaken to clarify the clinical course and prognosis of adult patients with primary IgA nephropathy (IgAN), especially with mild proteinuria or mild histological alternations. PATIENTS AND METHODS: A population of 735 IgAN patients whom we were able to observe for more than two years was examined. RESULTS: A total of 115 patients (15.6%) was on dialysis during the observation period. The overall 5-year renal survival rate was 92.0%. On the other hand, 166 patients (22.6%) were in clinical remission. A group with mild proteinuria included 197 patients (26.8%). Forty-seven patients of this group showed minor glomerular abnormalities, whereas 12 patients with mild proteinuria showed severe mesangial involvement. Three patients with mild proteinuria were on dialysis during the observation period, whose proteinuria was increased during the clinical course. A group with minor glomerular abnormalities included 82 patients (11.2%). Forty-seven patients of this group showed mild proteinuria, of whom 12 patients showed moderate proteinuria. However, three patients with minor glomerular abnormalities who were not on dialysis showed loss of renal function. CONCLUSION: These results indicated the heterogeneity of the course and prognosis in IgAN. Even if a patient's initial clinical or histological findings are comparatively mild, strict follow-up management is needed.

Adolescent↗
PubMed1999

Dieulafoy's lesion of the esophagus as a probable complication of Takayasu's arteritis.

Dieulafoy's lesion is an abnormal submucosal artery in the gastrointestinal tract characterized by massive gastrointestinal bleeding. We describe a patient who developed Dieulafoy's lesion of the esophagus in the course of isolated pulmonary Takayasu's arteritis. Angiographic findings indicated a relationship between pulmonary arterial involvement of Takayasu's disease and Dieulafoy's lesion of the esophagus. This observation represents the first report of the association between Takayasu's arteritis and Dieulafoy's lesion of the esophagus.

Adult↗
PubMed1994

Alteration in protein-tyrosine phosphatase of rat epithelial cells by RSV-transformation: application of phospho-tyrosyl glutamine synthetase to the study of protein-tyrosine phosphatase.

We prepared phospho-tyrosyl glutamine synthetase (P-GS) with suppressed activity from a highly adenylylated glutamine synthetase and applied it to the assay of protein-tyrosine phosphatase (PTPase) present in non-malignant rat liver cells (BRL) by RSV-transformation. The maximum PTPase activity toward P-GS was observed at neutral pH (pH 7.5-8.0) in the soluble and particulate fractions prepared from both BRL and RSV-transformed (RSV-BRL) cells. At low activity levels (< about 0.3 U), the PTPase activity in each fraction was proportional to the sample protein concentration (A280) and the specific activity of PTPase in the soluble fraction of BRL cells was about twofold higher than that in the soluble fraction of BRL cells, while those in particulate fractions of BRL and RSV-BRL cells were almost the same as each other. Soluble fractions of BRL and RSV-BRL were subjected to molecular-sieve and anion-exchange chromatographies. One major PTPase activity, with an M(r) of about 40,000 (40k), was detected in the BRL soluble fraction, and two were detected in the RSV-BRL soluble fraction with M(r)s of about 40k and 60k. The 40k PTPases in BRL and RSV-BRL had the same profiles on anion-exchange chromatography, but the 60k PTPase in RSV-BRL cells showed a different profile. We suggest that the RSV-transformation of BRL cells induced the appearance of the 60k PTPase in the soluble fraction.

Animals↗
PubMed1991

Detection of anti-nuclear antibodies from patients with systemic rheumatic diseases by ELISA using HEp-2 cell nuclei.

A microtiter plate was coated with cell nuclei from HEp-2 cells, and the stabilized nuclei were fixed with acetone for an enzyme-linked immunosorbent assay (ELISA). Autoantibodies against nuclear antigens were detected from the sera of patients with various systemic rheumatic disease but not from healthy individuals by means of the nucleus ELISA procedure. Ninety-one percent of antinuclear antibody (ANA)-positive sera as demonstrated by immunofluorescence (IF) test were also judged as positive for ANAs by the nucleus ELISA and 5% of them as pseudo-positive. Patient's sera with homogeneous and fine-speckled IF patterns displayed the highest ELISA titers. A large portion of ss-A/Ro antigen is localized in the cytoplasm; therefore, anti-ss-A/Ro antibody was hardly detected by nucleus ELISA. The population of ANAs detectable by nucleus ELISA included anti-ss-B/La, anti-DNA, anti-histone, anti-Sm, anti-RNP, and anti-scl-70.

Antibodies, Antinuclear↗
PubMed1989

Selective killing of carcinoembryonic-antigen (CEA)-producing cells in vitro by the immunoconjugate cytorhodin-S and CEA-reactive cytorhodin-S antibody CA208.

Cytorhodin-S, an anthracycline derivative, was covalently coupled to a monoclonal antibody (mAb) CA208, against carcinoembryonic antigen (CEA) in order to achieve selective killing of a CEA-producing colon carcinoma cell line, COLO 205. The conjugate (15 molecules of drugs/antibody) retained substantial antibody activity as well as drug activity as assessed by enzyme-linked immunosorbent assay and 24-h L1210 proliferation assay, respectively. Furthermore, the conjugate inhibited the growth of COLO 205 cells in a short-term cytostatic assay. This cytostatic effect of the immunoconjugate on COLO 205 cells was inhibited in a dose-dependent manner by pretreatment of the cells with unconjugated CA208 mAb. In addition, chloroquine, a lysosomotropic agent, inhibited the cytostatic effect of the immunoconjugate, indicating the involvement of lysosomal enzymes in releasing drugs from the immunoconjugate. The antibody (CA208) was significantly incorporated into the cytoplasm of COLO 205 cells as demonstrated by immuno-electron microscopy. These in vitro results indicate that cytorhodin-S may be a good partner in immunoconjugates. However, in vivo animal experiments with the immunoconjugate revealed that the immunoconjugate was not so effective in prolonging survival. Thus, in vivo efficacy of this immunoconjugate remains to be further improved in application to cancer immunotherapy.

Animals↗
PubMedDate not supplied

Crescentic glomerulonephritis associated with renal cell carcinoma after cancer immunotherapy.

A 59 year-old woman showed rapidly progressive glomerulonephritis during immunotherapy for metastatic renal cell carcinoma. She received unilateral nephrectomy and cytotoxic T lymphocyte (CTL) therapy for the treatment of retroperitoneal lymph node metastasis of renal cell carcinoma. With CTL therapy, her retroperitoneal lymph node mass decreased in size. One year after the third round of CTL therapy, her serum creatinine was increased and massive proteinuria occurred. Her renal biopsy specimen revealed necrotizing and crescentic glomerulonephritis with immune complex deposition. Her retroperitoneal lymph node mass continued to decrease in size. Consequently, for the purpose of avoiding interfering with the CTL therapy, we performed double filtration plasmapheresis (DFPP) monotherapy for removal of immune complexes without using immunosuppressive drugs or prednisolone. After 24 sessions of DFPP, her serum IgG was reduced from 3,942 mg/dL to 2,400 mg/dL, and proteinuria (from 9.0 g/day to 0.9 g/day) and renal function (serum creatinine; from 5.6 mg/dL to 2.2 mg/dL) also improved. However, 3 months after the final DFPP, she expired due to perforation of the colon. The autopsy sample of the kidney showed that most of the glomeruli were obsolescent, but immunoglobulin depositions were reduced and necrotizing lesions were diminished. In the patients with RPGN associated with renal cell carcinoma, renal functional recovery has not been observed upon immunosuppressive treatment. Consequently, plasmapheresis is considered to be one of the effective and safe methods for patients with this association. We also discuss previous reports of RPGN associated with renal cell carcinoma, or RPGN after cancer immunotherapy.

Biopsy↗