Search PubMed⌕ Search

Biomedical subjects

M Nagase

Publications and source records attributed to M Nagase.

At least 181 records · Page 10Linked to original sources
PubMed1985

[Antigenicity of alumina ceramic and calcium phosphate ceramics--genetic control of the immune response].

Antigenicity of alumina ceramic, hydroxyapatite ceramic and tricalcium phosphate ceramic was studied by induction of footpad swelling in C57BL/6 mice immunized by ceramics with Freund's complete adjuvant. Significant footpad swelling was observed in mice immunized with tricalcium phosphate ceramic at 2 and 4 weeks after immunization. Antigenic specificity was demonstrated between tricalcium phosphate ceramic and fetal bovine serum in crisscross. Time course of the reaction suggested that delayed-type hypersensitivity played an important role in footpad swelling. These results indicate that tricalcium phosphate ceramic has antigenicity to C57BL/6 mice. Antigenicity of alumina ceramic and hydroxyapatite ceramic was not demonstrated in this study. A positive footpad reaction to tricalcium phosphate ceramic was shown in C57BL/10 (H-2b) and C57BL/10 X BR (H-2k), but was not observed in C57BL/10 X D2(H-2d). These results suggest that this response to tricalcium phosphate ceramic was under control by a gene located within the major histocompatibility complex.

Aluminum↗
PubMed1985

Reticuloendothelial system and glomerular deposition of heat-aggregated human IgG.

The influence of functional impairment of reticuloendothelial system on glomerular deposition of heat aggregated human IgG (HAIgG) was studied. I-125 HAIgG was injected to mice treated either with dextran-containing 0.9% saline or with the saline alone. The HAIgG clearance rate from the blood decreased in the dextran-treated mice. The chronologically measured HAIgG contents in the liver, spleen and glomeruli increased in the dextran-treated animals. Immunofluorescent technique also demonstrated an increase in HAIgG and host C3 in the glomeruli. The glomerular hypercellularity was not demonstrated morphologically. Assuming that the function of the hepatic Kupffer cells principally affect the clearance rate of the foreign macromolecules from the blood, it is likely that the dextran administration impaired the function of these cells to digest the phagocytosed HAIgG, and that consequently the injected HAIgG stayed longer in the blood. Thus, increased supply of the HAIgG from the blood and/or the dextran-induced reduction of digesting function of the mesangial cell per se might have led to the accumulation of glomerular HAIgG. We suggest, therefore, that even small amount of immune complex may induce immune complex-mediated glomerular lesion, when associated with long lasting functional impairment of the Kupffer cells.

Animals↗
PubMed1985

Enzyme immunoassay of C1q and its application to the detection of C1q antigens in urine.

A highly sensitive enzyme immunoassay for the determination of C1q, a subcomponent of the first component of complement, C1, was developed to determine C1q in body fluid. Anti-C1q F(ab')2 fragments were immobilized on silicone rubber and after the interaction of anti-C1q with C1q, Fab' fragments of anti-C1q coupled with beta-D-galactosidase were added. The amounts of C1q were measured by enzymatic activity of beta-D-galactosidase to cleave 4-methylumbelliferyl-D-galactoside. A calibration curve of C1q indicates that C1q could be determined in the range of 0.3 ng/ml-1 mg/ml, the optimal range being 1-100 ng/ml. While C1q was not detectable in the urine of healthy volunteers, C1q could be determined in the urine of patients with renal diseases. The highest level of C1q detected was 31.8 ng/ml in urine of chronic nephritis.

Complement Activating Enzymes↗
PubMed1985

Intraglomerular distribution of fibronectin in primary glomerular diseases.

The intraglomerular distribution of fibronectin was examined in 152 renal biopsy specimens with the direct immunofluorescence technique. Fibronectin was detected only in the mesangial area in normal glomeruli, while in proliferative glomerulonephritis, it extended from the mesangium to the pericapillary regions proportionately with the proliferative changes. In membranoproliferative glomerulonephritis, fibronectin globally extended in the glomeruli. Also in membranous nephropathy, fibronectin was observed in the capillary walls despite an absence of proliferation. Electron microscopic examinations revealed that the glomeruli with the pericapillary distribution of fibronectin were mostly found in stage II or III, as determined by WHO criteria. The double immunofluorescence technique demonstrated that in membranous nephropathy fibronectin was on the inner side of the glomerular basement membrane, and that in membranoproliferative glomerulonephritis fibronectin extended concomitantly with the expansion of mesangial matrix. These findings suggest that intraglomerular fibronectin is localized only in the mesangial area in normal glomeruli, and that the pericapillary distribution of fibronectin occurs not only by mesangial proliferation but also by additional unknown mechanisms.

Animals↗
PubMed1984

[The physiological significance of the hippocampus on the inhibitory effects of corticosterone upon the estradiol-induced LH and FSH surges in rats].

The effects of corticosterone (CS) on the gonadotropin surge induced by estradiol-benzoate (E2) were studied in adrenalectomized and ovariectomized (ADRX-OVEX) rats. The results are as follows. In ADRX-OVEX rats implanted with E2-tablets in the bilateral axillae, LH and FSH surges occurred 4 days after the implantation of E2, peaking at 17:00 h. The levels of these surges were markedly higher than those in OVEX rats similarly treated but were attenuated significantly by the subcutaneous injection of CS (25 micrograms in sesame oil) given at 12:00 h. The CS implantation (0.5 micrograms in 2 microliters sesame oil) into the dorsal hippocampus at 15:00 h significantly inhibited the levels of LH and FSH surges in ADRX-OVEX rats with E2-tablets. The effect of the CS implant in the lateral septal nucleus was also inhibitory but not statistically significant. The CS administration in the ventral part of the midbrain tegmentum did not elicit any change in the surge of LH and FSH. In animals with the dorsal fornix-section at the post-anterior-commissural level, surges of LH and FSH also occurred in the afternoon of the 4th day after the E2-tablets implantation, but the levels of LH and FSH were not significantly altered by an intravenous injection of CS (5 micrograms in saline) at 15:30 h. It was suggested the CS circulating in the blood would induce a rise of hippocampal activity which would exert a suppressive influence on the gonadotropin release.

Adrenalectomy↗
PubMed1984

Glomerular alterations in uranyl acetate-induced acute renal failure in rabbits.

The study was performed to elucidate the progression and regression of superficial and inner glomerular alterations in uranyl acetate-induced renal failure in rabbits. Fifteen hours after the drug injection, creatinine clearance (CCr) decreased to 55% of controls with slightly elevated plasma creatinine concentration (initiation stage). After 5 days, urine flow and CCr decreased to approximately zero, with severe azotemia (maintenance stage). Scanning electron microscopic observations in these stages revealed a flattening and spreading of podocyte cell bodies associated with loss of epithelial foot processes, and reduction in the density of endothelial fenestrae. These changes were more advanced in the maintenance stage. Glomerular and fenestral diameters did not significantly change in the initiation stage but increased in the maintenance stage. There was no significant difference in these morphologic alterations, however, between the superficial and inner glomeruli. Glomerular alterations reverted to normal within 14 days, with good recovery of glomerular function. The findings show no significant difference in the progression or regression of the glomerular changes between the superficial and deep cortex. These morphologic changes may play a role in the reduction of CCr observed in this model.

Acute Kidney Injury↗
PubMed1984

Suppression of proteinuria by dipyridamole in rats with aminonucleoside nephropathy.

Nephrosis was induced by single injections of puromycin of aminonucleoside to rats which were divided into two groups; the experimental group receiving dipyridamole in addition to aminonucleoside and the control group receiving aminonucleoside alone. 24-hour urinary albumin increased in rats of both groups after aminonucleoside injections. However, the experimental rats excreted significantly less albumin than controls. On the contrary, there was no significant difference in urinary IgG between the two groups. The stainings of anionic sites of glomerular basement membrane using ruthenium red revealed the reduction of anionic charge in the glomerular basement membrane of both groups, but the decrease of anionic charge was suppressed in lamina rara interna of the experimental rats. Considering the role of charge barrier in the glomerular basement membrane, it is concluded that the maintenance of anionic charge in experimental rats is causally related to the suppressed excretion of albumin.

Animals↗
PubMed1983

Recurrent melanotic neuroectodermal tumour of infancy. Case report and survey of 16 cases.

A case of melanotic neuroectodermal tumour of infancy (MNTI) with rapid recurrence is described, together with a survey of 16 reported recurrent cases. The recurrent lesion was successfully treated by wide excision of the maxilla. The recurrent tumour had two lesions of different natures, one consisting of a lobular mass indistinguishable from the primary tumour but located remote from the original site and the other showing diffuse infiltration of tumour cells deep in the medulla of the maxilla. A survey of the recurrent cases indicated that, although incomplete removal of the primary tumour, dissemination of tumour cells during surgery and a multicentric origin could be the causes of a recurrence, the presence of a silent lesion which may express an aggressive growth on stimulation may also explain the complex behaviour of the tumour.

Humans↗
PubMed1983

Changes in pituitary-adrenal function under continuous exposure to hypoxia in male rats.

The plasma corticosterone concentration and incorporation of 14C-1-acetate into adrenocortical hormones were measured in male rats exposed to hypoxia (12.5% O2 in N2 balance) for periods of 30 min--14 days. Hypoxia significantly increased the weight of the adrenal and pituitary glands in early stages of exposure. However, weight returned to the control level on the 14th day of exposure. Hypoxia consistently decreased the weight of the thymus. Hypoxia elevated the plasma corticosterone concentration in the early stages of exposure. However, the elevated corticosterone level gradually decreased by the 7th day. The corticosterone level at this stage was lower than in the control. The corticosterone concentration returned to the control level on the 14th day. Hypoxia significantly facilitated incorporation of 14C-1-acetate into corticosterone and cortisol in the adrenal homogenate. The elevated incorporation was maintained until the 7th day and gradually decreased to the control level there after. Body weight was decreased by hypoxia (12 gram in 24 hours). On the 5th day, the weight returned to the control level. Hematocrit increased gradually during 14 days of hypoxia exposure. These results suggest that pituitary-adrenal function is greatly facilitated by 1-6 hours of hypoxia exposure, and hypoxia acclimatization is accomplished humorally within 14 days of exposure in rats.

Acetates↗