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Biomedical subjects

A Fukatsu

Publications and source records attributed to A Fukatsu.

68 records · Page 4Linked to original sources
PubMed1989

A case of nephrotic syndrome with glomerular lipoprotein deposition with capillary ballooning and mesangiolysis.

A 33-year-old man with nephrotic syndrome and rapid deterioration of renal function showed curious glomerular morphological abnormalities. Ballooning of the glomerular capillaries due to a substance accumulated in the capillary lumina and mesangiolysis were prominent histological features. The deposits in the capillary lumen were positive for Sudan III staining, and also for beta-lipoprotein, apoprotein B and apoprotein E by immunofluorescent technique. The staining of beta-lipoprotein in a flower leaf pattern was a striking characteristic, while such staining was negative when studied in 20 patients with nephrotic syndrome who were used as controls. Based on these findings, the morphological abnormalities in this case were considered to be related to lipoprotein deposition in the glomeruli. This case is thought to be the first reported in a complete form in the literature which could be classified as a new kind of disease related to lipoprotein metabolism abnormalities.

Adult↗
PubMed1989

Interaction of antibodies with human glomerular epithelial cells.

We tested the hypothesis that the pathogenesis of human idiopathic membranous glomerulonephritis is similar to that of Heymann glomerulonephritis, a model of membranous glomerulonephritis induced in rats by immunization with renal brush border preparations; the characteristic subepithelial deposits result from interaction of antibodies with a brush border antigen (gp330) expressed on the plasma membrane of glomerular visceral epithelial cells (GEC), followed by redistribution and shedding of gp330 immune complexes. The experiments were performed in cultured glomerular visceral epithelial cells, in living monkeys and rats, and in isolated perfused human, monkey, and rat kidneys. Antigens from plasma membranes of human renal brush border vesicles (HBBV) and GEC vesicles (HGECV) and their corresponding polyclonal and monoclonal antibodies reactive with human and monkey GEC were prepared. First, polyclonal antibodies to HGECV bound diffusely to cultured GEC; monoclonal antibody 8G5, recognizing a 60-kDa protein, mainly bound to the coated pits and apical invaginations; both polyclonal HGECV and 8G5 monoclonal antibodies induced antigen redistribution (capping) at 37 degrees C. Second, monkeys were actively or passively immunized, and isolated human and monkey kidneys were perfused with the antibodies. Active immunization with HBBV induced tubular immune deposits, whereas active immunization with HGECV did not provoke renal lesions. After passive immunization HBBV and HGECV antibodies bound diffusely to glomerular cells, and subepithelial deposits were observed during the autologous phase; in contrast, 8G5 induced early (day 3) granular deposits. Third, fine granular deposits developed in glomeruli of human and monkey kidneys perfused for 4 hours at 37 degrees C with 8G5; these deposits were more difficult to detect by electron microscopy than those occurring in kidneys of Lewis rats perfused with sheep antiHBBV. The results show that some antibodies redistribute antigens at the surface of human and monkey GEC in vitro, in vivo, and ex vivo and induce formation of granular deposits in human glomerular capillary walls. Failure to induce more severe lesions in human and monkey kidneys may be ascribed to lack of GEC antigens comparable to rat gp330, insufficient cross linking by monoclonal antibody, lack or insufficient concentration of epitope-specific antibodies, insufficient time of kidney perfusion, or a combination of these factors.

Animals↗
PubMed1988

The glomerular distribution of type IV collagen and laminin in human membranous glomerulonephritis.

The glomerular distribution of type IV collagen and laminin, the major collagenous and noncollagenous components of the glomerular basement membrane, was studied by immunofluorescence microscopy in idiopathic and lupus membranous glomerulonephritis. Affinity-purified antibodies against type IV collagen reacted preferentially with the inner aspect and irregularly with the adjacent outer area of the thickened basement membrane. In contrast, laminin was detected along the inner aspect of the glomerular basement membrane, in subepithelial basement membrane protrusions ("spikes"), and in the newly formed basement membrane layer above the immune deposits. We conclude that type IV collagen and laminin do not codistribute in the newly formed matrix. This aberrant antigenic distribution may reflect a loss of coordinate biosynthesis or degradation of these matrix components by visceral epithelial cells.

Basement Membrane↗
PubMed1988

Local formation of immune deposits in rabbit renal proximal tubules.

Rabbits passively immunized with goat antibodies to rabbit angiotensin converting enzyme (ACE), an enzyme synthesized in the endoplasmic reticulum and mainly expressed on the apical membranes of the cells of proximal tubules, developed mild and transient immune deposits in this segment of the nephron. Granular deposits of goat IgG, rabbit ACE and C3 were found in the basolateral compartment and were maximal during the first week of immunization when the highest titers of anti-ACE antibodies were present. As the antibody titer fell to an undetectable level, the immune deposits were rapidly cleared and were virtually absent 21 days after the injections. Artificial increase of glomerular permeability allowed focal binding of ACE antibodies to the brush border of some tubules, but did not significantly alter the pattern of immune injury at the base of tubular cells. The data are consistent with the interpretation that the immune deposits result from in situ formation of immune complexes. This mechanism would involve passage of circulating antibodies across the tubular basement membrane and their combination with ACE associated with tubular cell surface membranes.

Animals↗
PubMed1987

Studies on the formation of glomerular immune deposits in brown Norway rats injected with mercuric chloride.

Brown Norway rats injected with mercuric chloride (HgCl2) develop autoantibodies which immunolocalize along the glomerular basement membrane at first in a linear pattern and then in a granular pattern. The aim of this study was to characterize the specificity of these antibodies and to investigate the mechanisms responsible for the formation of granular immune deposits in the subepithelial zone of the glomerular basement membrane. The rats were found to develop circulating anti-laminin, anti-type IV collagen, anti-heparan sulfate proteoglycan, and anti-entactin antibodies. Antibodies against laminin and type IV collagen were found in relatively high titers in the sera and were specifically concentrated in the nephritic kidneys. Antibodies eluted from the nephritic kidneys with either linear or granular deposits reacted with basement membrane antigens synthesized and secreted by cultured rat glomerular visceral epithelial cells. Thus, in this model, the interaction of anti-laminin and type IV collagen antibodies with antigens secreted by glomerular visceral epithelial cells might, together with other mechanisms, contribute to the formation of granular immune deposits in the subepithelial part of the glomerular basement membrane.

Animals↗
PubMed1987

Glomerulonephritis induced in the rabbit by antiendothelial antibodies.

The effects of interaction between endothelial angiotensin converting enzyme (ACE) and goat anti-rabbit ACE (GtARbACE) antibodies were studied in rabbit glomeruli. By immunofluorescence ACE was not detectable in normal glomeruli. However, when kidneys were perfused with GtARbACE antibodies glomerular bound IgG was seven times higher than that of non-immune IgG and granular deposits of goat IgG were found on the endothelium of glomeruli and arteries. Rabbits injected intravenous for 4 d with GtARbACE antibodies showed on day 1 granular deposits of goat IgG on the glomerular endothelium; from day 3 to 24 there was gradual development of subepithelial deposits of goat IgG, rabbit IgG and C3. When GtARbACE antibodies were similarly injected into proteinuric rabbits there was formation of subepithelial granular deposits of goat IgG and ACE. The results document that a glomerular endothelial antigen is redistributed in vivo by a specific ligand, an event associated with formation of immune deposits. Furthermore, if the glomerular permeability is artificially increased, immune complexes shed from nonglomerular endothelia into the circulation can contribute to form subepithelial immune deposits.

Animals↗
PubMed1979

Application of magnification radiography to the biliary system.

Magnification radiography was applied for the diagnosis of the biliary tract diseases including cancer. Our X-ray unit was consisting of HITACHI DR-155-23 U-6M-55P and 0.1 mm focal-spot tube, FFD 80 cm giving a magnification of x2 with the conditions of 60 kVp, 20 mA, 0.8 sec. Intensifying screens such as Kyokko LH II (for a standard sized subject) or DuPont Q II (for an obese subject) were used in combination with Fuji RX films. We confirmed a high diagnostic value in revealing early lesions of this sytem. The skin dose test indicated that this technique was routinely applicable with safety for clinical use.

Biliary Tract↗
PubMedDate not supplied

Clinical benefits and tolerability of increased fill volumes in Japanese peritoneal dialysis patients.

BACKGROUND: Increasing fill volume is an effective means of improving clearances in patients on peritoneal dialysis (PD). Since Japanese PD patients are physically smaller than their Western counterparts, there is some concern that PD patients in Japan may be unable to tolerate larger fill volumes. OBJECTIVE: To determine patient tolerance and changes in solute clearance and net ultrafiltration resulting from increased fill volumes in Japanese patients on PD. DESIGN: Prospective double-blind study, randomizing patients to three different fill volumes (2.5% dextrose solution: 1.5 L, 2.0 L, or 2.5 L) administered in random order on three different occasions separated by 1 week. RESULTS: Twenty-one patients with a mean age of 55.4 +/- 2.1 years and a mean body surface area of 1.66 +/- 0.03 m2 were studied. On a scale of 0 to 10, patients' mean discomfort scores were 2.14 +/- 0.59, 3.48 +/- 0.54, and 3.81 +/- 0.63 (p = 0.047) at the end of the 1.5-L, 2.0-L, and 2.5-L dwells, respectively. There were no reports of cramps or shortness of breath with any fill volume. Patients were able to correctly guess the actual fill volume for only 34 of the 63 total exchanges (54.0%). Increasing fill volume resulted in an incremental improvement in peritoneal creatinine clearance, from 3.74 +/- 0.16 to 4.49 +/- 0.21 (p < 0.001, 2.0 L vs 1.5 L) to 5.12 +/- 0.20 mL/minute (p< 0.001, 2.5 L vs 2.0 L) for 1.5-L, 2.0-L, and 2.5-L dwells, respectively. Peritoneal urea clearance also increased significantly, from 5.65 +/- 0.13 to 7.04 +/- 0.17 (p < 0.001, 2.0 L vs 1.5 L) and 8.16 +/- 0.29 mL/minute (p < 0.001, 2.5 L vs 2.0 L), with incremental increases in fill volume. Similarly, net ultrafiltration in a 4-hour dwell increased significantly with fill volume, from 255.24 +/- 24 mL with 1.5 L, to 356 +/- 24 (p < 0.004, 2.0 L vs 1.5 L) and 392 +/- 29 mL (p < 0.086, 2.5 L vs 2.0 L) in patients receiving 2.0 L and 2.5 L, respectively. CONCLUSION: Increasing the fill volume results in improvement in solute clearance and net ultrafiltration in Japanese PD patients, with minimal increase in patient discomfort. A large percentage of patients were unable to identify the actual fill volume.

Body Surface Area↗