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Biomedical subjects

M Nagase

Publications and source records attributed to M Nagase.

At least 19 recordsLinked to original sources
PubMed1992

Remodeling of large bone defects in the treatment of space-occupying lesions. Curettage without bone graft for treating benign bone tumors.

Curettage without bone graft was performed in 17 patients with benign bone tumors and tumor-like lesions. New bone formation with uniformly increased radiodensity appeared in serial plain radiographs within 3 months after the operation. The average period before full weight could be borne on the lower extremities was 14 weeks. Computed tomography revealed that the central part of the bone lesions persisted without bone formation. The thickening of cortical bone was predominant. These data indicate that enough mechanical strength for daily activity will be recovered by bone within 4 months after curettage without any filler, although remodeling continues for over a year. It is suggested that bone graft and implantation of "biomaterials" are not necessary in patients, especially younger ones, with benign bone tumors or tumorous conditions.

Adolescent↗
PubMed1992

Intraglomerular fibronectin in rat experimental glomerulonephritis.

To clarify the mechanisms of glomerular pericapillary fibronectin deposition in human membranous nephropathy and mesangial proliferative glomerulonephritis, intraglomerular fibronectin distribution was examined by light and electron microscopy using the experimental rat models of Heymann and nephrotoxic serum nephritis. As previously demonstrated by immunofluorescence microscopy (Pettersson and Colvin 1978; Ikeya et al. 1985, 1986), fibronectin was distributed in the mesangial areas and occasionally on percicapillary walls of normal glomeruli, while in nephrotoxic serum nephritis and Heymann nephritis, fibronectin was diffusely located along glomerular capillary walls as well as in the mesangium. By immunoelectron microscopy using the immunogold technique, fibronectin was also noted in the mesangial areas and the lamina densa of the glomerular basement membrane (GBM) in normal glomeruli. In nephrotoxic serum nephritis, fibronectin was seen around mesangial cells situated between endothelial cells and the GBM, suggesting that pericapillary fibronectin in nephrotoxic serum nephritis reflects mesangial extension. However, in Heymann nephritis, it was found uniformly in the lamina rara interna, lamina densa and lamina rara externa of the GBM, indicating no specific relation to glomerular cells. When sections of normal and both experimental nephritis kidneys were incubated with fluorescein isothiocyanate conjugated with rat plasma fibronectin, a linear pattern of fluorescein staining along the glomerular capillary walls was observed in Heymann nephritis but not in normal or nephrotoxic serum nephritic rats. The GBM in Heymann nephritis would thus appear to have an affinity for plasma fibronectin. Based on the above findings, fibronectin in the GBM of rats with Heymann nephritis may reasonably be concluded to originate from the plasma.

Animals↗
PubMed1992

Toxicity of silica-containing calcium phosphate glasses demonstrated in mice.

Suspensions of calcium phosphate glass containing various concentrations of silica (glass composition (moles): 100 Ca(PO3)2 to x SiO2,x = 0, 5, 10, 15 or 40) dispersed in normal saline were injected intraperitoneally into C57BL/6 mice to determine the mortality within 30 days. The mortality was 0/10, 3/10, 9/10, 10/10 and 10/10 at x = 0, 5, 10, 15 and 40 mol of silica, respectively. By means of inductively coupled plasma analysis, the amount of dissolved silica (Si4+) in water at 37 degrees C from the calcium phosphate glass depended on the amount of silica in the glasses. The mortality of mice was directly proportional to the silica content of the glass injected intraperitoneally. These results clearly show that the dissolved silica (Si4+) from the glass, monomeric or low molecular silicic anion, is highly toxic. The SiO2 component in biomaterials has toxic potential when dissolved in the body.

Animals↗
PubMed1992

Alterations of anionic charge and/or sites of the glomerular basement membrane in the heterologous phase of passive Heymann nephritis.

Alterations of the anionic charge and/or sites of the glomerular basement membrane (GBM) in the heterologous phase of passive Heymann nephritis (PHN) were studied. Rats with PHN induced by a single injection of anti-Fx1A IgG were examined at days 1, 2, 3 and 4. The left kidney was perfused with ruthenium red (RR) solution as a cationic probe. The RR particles (= anionic sites) in the GBM were counted and expressed as the number of RR particles per unit length of GBM. For quantitative determination of the total anionic charge of the GBM, the GBM-bound ruthenium (= anionic charge) was measured with an atomic absorption spectrophotometer (AAS). Abnormal proteinuria corresponding to a decrease in anionic charge was detected at days 3 and 4. The anionic sites in the lamina rara externa (LRE) adjacent to immune complex (IC) deposits were found to have diminished earlier from day 1 onwards. This diminution was largely confined to areas adjacent to the IC deposits and was significantly correlated with the amount of urinary albumin excretion. Proteinuria in the heterologous phase of PHN would thus appear to be causally related to a decrease in the number of anionic sites in the LRE adjacent to IC deposits.

Animals↗
PubMed1991

Altered localization of antigen recognized by proteinuria-inducing monoclonal antibody in experimental nephrosis.

Change in the localization of the antigen recognized by the proteinuria-inducing monoclonal antibody (MA) 5-1-6 in experimental nephrosis was studied by indirect and biotin-avidin immunofluorescence, and immunoperoxidase at light and electron microscopical levels. The proteinuric state was induced by the administration of the aminonucleoside of puromycin (PAN) or adriamycin. The antigen decreased in quantity and/or its distribution changed with an increase in the amount of protein excreted in both experimental models. Recovery from the alterations observed during the development and proteinuria appeared to occur when PAN-induced proteinuria subsided. This antigenic molecule may thus be essential for maintaining the normal permselectivity of glomerular capillary walls.

Animals↗
PubMed1991

Evaluation of a bone substitute prepared from alpha-tricalcium phosphate and an acid polysaccharide solution.

Tissue response to a readily consolidating material prepared by mixing alpha-tricalcium phosphate (alpha-TCP) powder with a glycolic acid dextran solution and to this consolidating material combined with particulate hydroxylapatite (HA) was studied after implantation in the subperiosteal space of the mandible in rabbits. Active new bone formation comparable to that seen on HA implants was observed around the two compounds. The newly formed bone was in direct contact with the HA as well as the readily consolidated material and little adverse effect resulting from the glycolic acid and dextran was observed. Because the readily consolidating material was firm and could be contoured into any shape during the process of consolidation, it may be quite useful as a bone substitute and as an adherent for HA particles for reconstructive bone surgery, overcoming the disadvantages inherent to the particulate form of HA.

Alveolar Ridge Augmentation↗
PubMed1991

Nephrotoxic serum nephritis in nude rats: the roles of host immune reactions.

A description is made of renal lesions in rats induced by heterologous (rabbit) nephrotoxic serum with or without subsequent host immune reactions against it and the effects of immune reactions on the course of classical nephrotoxic serum (Masugi) nephritis are discussed. The disease was induced by injecting congenitally athymic ACI nude rats (rnu/rnu) and their normal heterozygous littermates (rnu/+) with rabbit anti-rat glomerular basement membrane (GBM) antiserum. In the autologous phase, rat IgG and immunoglobulins were localized in a linear pattern along capillary walls only in nephritic heterozygous rats. In the indirect plaque-forming cell (PFC) assay against rabbit immunoglobulins in the autologous phase, significantly more PFC could be detected in nephritic heterozygous rats than in nephritic nude rats. The nude and heterozygous rats were essentially the same with respect to the amount of urinary protein, histological change and clinical course. At least in classical nephrotoxic serum nephritis in rats, host immune reactions against GBM bound heterologous nephrotoxic serum were concluded to have no effect on the course of the disease.

Animals↗
PubMed1991

Plasmapheresis in conjunction with the dextran sulfate cellulose column for hypertriglyceridemic patient: a comparison with familial hypercholesterolemia.

For assessment of the usefulness of a dextran sulfate cellulose (DSC) column in the conduct of plasmapheresis (DSC lipoprotein adsorption, DSC-LA) for patients with hypertriglyceridemia on hemodialysis, a study was conducted to determine whether the adsorption of lipoproteins on a column varies in response to a variation in the lipoprotein composition. A patient with type V hyperlipoproteinemia on hemodialysis, a patient with type IIa homozygous, and a patient with type IIa heterozygous familial hypercholesterolemia were used in this study. In all patients, apolipoprotein B- and E-containing lipoproteins were removed preferentially by a DSC column. Following DSC-LA, abdominal pain before DSC-LA in a patient with type V hyperlipoproteinemia subsided, and regression of tuberous and tendinous xanthomas was induced in familial hypercholesterolemia. In cases of hyperlipoproteinemia, this column thus appears to exert a therapeutic effect regardless of the type of disease.

Achilles Tendon↗
PubMed1991

Crystal-storing histiocytosis and crystalline tissue deposition in multiple myeloma.

Systemic distribution of crystal-storing histiocytes, increasing in number, and widespread crystalline tissue deposition were found in a 75-year-old man with a 5-year history of IgG-kappa-type multiple myeloma associated with corneal opacity and chronic renal failure. Characteristic crystalline inclusions were present not only in myeloma cells but also in cornea, epithelial cells of glomeruli, tubuli, Bowman's capsules, and choroid plexus. Histiocytes had particularly infiltrated the renal interstitium. These inclusions were positive by immunofluorescence for kappa light and gamma heavy chains. By electron microscopy, the inclusions were filled with fine crystalline hexagonal columns, each possessing a core structure. Of various factors generally considered responsible for renal failure in multiple myeloma, marked infiltration of histiocytes and the nephrotoxic effects of light chain appeared most relevant in the present case.

Aged↗
PubMed1990

Structure and expression of mouse furin, a yeast Kex2-related protease. Lack of processing of coexpressed prorenin in GH4C1 cells.

We have cloned and sequenced a mouse cDNA encoding the 793-residue amino acid sequence of furin, which is a protein homologous to the yeast Kex2 protease. The entire sequence is 94% identical to that of human furin, and it contains the 289-residue sequence of the subtilisin-like catalytic domain. Within this region, 99, 64, and 53% of the amino acids are identical to those of human furin, human PC2 (the other mammalian Kex2-like protein), and yeast Kex2, respectively. It has been proposed that furin is a mammalian prohormone processing enzyme which cleaves precursors at paired basic amino acids, based on the fact that the Kex2 protease is responsible for processing of alpha-mating factor and killer toxin precursors at dibasic sites. However, Northern blot analysis has revealed that a furin mRNA transcript is present in all tested mouse tissues and culture cell lines, including those known not to process prohormones. Moreover, when furin and a prohormone, prorenin, have been coexpressed in mammalian cells by DNA transfection, no processing has been observed. These observations fail to show a role for furin, a Kex2-like mammalian protease, in prohormone processing.

Amino Acid Sequence↗
PubMed1990

Replantation: an analysis of 29 teeth.

The results of replantation of 29 teeth are described. Maxillary incisors constituted 85% of 27 permanent teeth. The period between avulsion and replantation ranged from within an hour to 86 days, but the actual extraoral period was within 5 hours in all but one case. Nineteen of the 27 permanent teeth were functioning for 7 months to 6 years and 7 months postoperatively. Root resorption was the cause of tooth loss in five cases. The incidence of root resorption seemed to increase with the increase of the extraoral period, but it was not affected by the period between avulsion and replantation, the condition of supporting tissues, the degree of root formation, and the type and period of splinting, indicating multiple factors involved in determining the prognosis of replanted teeth. In conclusion, every effort should be made to preserve avulsed teeth even in unfavorable conditions.

Adolescent↗
PubMed1990

[Immunoglobulin G coating of ceramic powders enhances superoxide production].

Crystals and a group of ceramics used in joint replacement surgery were incubated with polymorphonuclear cells with and without adsorbed immunoglobulin G to study their ability to generate superoxide anion. All eight particles tested had the capacity to induce superoxide anion to at least some extent. Alumina ceramic and some of the ceramics adsorbed small amounts of immunoglobulin G onto their surfaces and the increment of superoxide production was also small. Both the augmentation of superoxide anion and the adsorption of immunoglobulin G to tricalcium phosphate ceramic and the remaining ceramics were intermediate. Synthetic monosodium urate crystals adsorbed immunoglobulin G most efficiently with large increments of superoxide anion. The increase in superoxide production by the adsorption of immunoglobulin G depended on the amount of immunoglobulin G bound onto crystals or ceramics. The greater phlogistic potential of some ceramics need to be taken into consideration in their clinical use.

Adsorption↗
PubMed1990

[Prolonged inflammatory reactions induced by ceramic powders in the rat air pouch model].

The subcutaneous air pouch of the male Sprague-Dawley rat was used to study inflammatory potential of artificial ceramics. Local leukocyte influx, proteinase, prostaglandin E2 (PGE2) and tumor necrosis factor (TNF) levels were measured after injection of hydroxyapatite ceramic (HAP), tricalcium phosphate ceramic (TCP) and apatite-wollastonite glass ceramic (GC) into the pouch. Synthetic monosodium urate crystals (MSU) were used as positive controls and normal saline (NS) as a negative control. The response was monitored over a period of 168 hours by irrigating the pouch with 5 ml of NS and withdrawing 4 ml. MSU produced the greatest response in leukocyte counts, proteinase and PGE2, whereas HAP, TCP and GC often appeared later than with MSU. TNF was significantly detected only after ceramics and not after MSU. The chronic and relatively prolonged reaction to HAP, TCP and GC suggests that an inflammatory reaction may occur after implantation of these ceramics in humans. The increased levels of TNF and production of PGE2, which are substances proposed to contribute to osteolysis associated with loosening, are of special interest for further research.

Animals↗
PubMed1990

HLA phenotypes in patients who have osteosarcoma.

Human leukocyte antigen (HLA) phenotypes were studied in twenty Japanese patients who had typical osteosarcoma. The HLA-A11 phenotype was found in ten (50 per cent) of the twenty patients, compared with 16.6 per cent of 235 control subjects (chi square = 13.248; p less than 0.0005)--an odds ratio of 5.026. These data suggest that major histocompatibility complex-linked genes may determine susceptibility to osteosarcoma.

Adolescent↗
PubMed1989

Apicoectomy with retrograde gutta-percha root filling.

Sixty-four teeth were treated by means of apicoectomy with retrograde gutta-percha filling with the use of new instruments that we devised. The new instruments consisted of a biangle explorer, angle reamers, and angle files. Operations with this technique showed a success rate of 95.3% (61/64 teeth). We conclude that our technique for apicoectomy with retrograde gutta-percha filling is not only simple in procedure, but also shows excellent results.

Adolescent↗