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Biomedical subjects

M Nagase

Publications and source records attributed to M Nagase.

At least 145 records · Page 8Linked to original sources
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↗
PubMed1989

Radiographic and microscopic evaluation of subperiosteally implanted blocks of hydroxylapatite-gelatin mixture in rabbits.

The efficacy of using gelatin as an adherent of particulate hydroxylapitite was studied by implanting preformed blocks of a hydroxylapatite-gelatin mixture subperiosteally on the buccal aspect of the mandible in rabbits. The rabbits were killed at 1, 2, 4, 12, and 24 weeks after implantation. After radiographic examination, excised specimens were decalcified and examined microscopically. The radiographic findings in the hydroxylapatite-gelatin group were essentially consistent with those of the hydroxylapatite group, except that in the hydroxylapatite group migration of particles was seen in some specimens. Microscopically the majority of the gelatin was unidentifiable at 1 week and there was no evidence of a rejection response. The degree of new bone formation and tissue response in hydroxylapatite-gelatin mixture group was essentially the same as in the hydroxylapatite group. The results indicate that gelatin is an excellent adherent for particulate hydroxylapatite, enabling easy handling and proper placement of the material with no inhibitory effect on new bone formation.

Animals↗
PubMed1989

Radiographic and microscopic evaluation of subperiosteally implanted blocks of hydrated and hardened alpha-tricalcium phosphate in rabbits.

Tissue response to preformed tricalcium phosphate (TCP) blocks prepared from alpha-tricalcium phosphate (alpha-TCP) powder by hydration and hardening at 80 degrees C was studied by implanting them subperiosteally on the buccal aspect of the mandible in rabbits. X-ray diffraction of the alpha-TCP powder showed a typical pattern of TCP, whereas a mixed pattern of TCP and hydroxylapatite was obtained after hydration and hardening. The radiographic findings at 4 weeks showed a tendency to bony union of the TCP block with the underlying bone. Microscopically, new bone that was being formed extensively from the underlying bone surface and filling the space between the block and bone at 4 weeks gradually changed into lamellar bone. There was no evidence of resorption of the TCP block throughout the experiment. The tissue response was essentially consistent with that to hydroxylapatite particles studied under similar conditions in our laboratory. It was concluded that the hydration and hardening of alpha-TCP powder may provide an implant block with a desirable contour that does not interfere with bone formation.

Animals↗
PubMed1989

Immunoglobulin G coating on crystals and ceramics enhances polymorphonuclear cell superoxide production: correlation with immunoglobulin G adsorbed.

Crystals and a group of ceramics used in joint replacement surgery were incubated with polymorphonuclear cells (PMN) with and without adsorbed immunoglobulin G (IgG). All 11 particles tested had the capacity to induce the production of superoxide anion (O2-) to at least some extent. Synthetic calcium pyrophosphate dihydrate crystals (CPPD) and several ceramics adsorbed small amounts of IgG and the increment of superoxide production was also small. Both the augmentation of O2- and the adsorption of IgG to hydroxyapatite type I synthetic crystals and the remaining ceramics were intermediate. Synthetic monosodium urate crystals adsorbed the most IgG and the O2- increments were large. The increase in superoxide production correlated with the amount of IgG bound onto crystals or ceramics. The greater protein binding and phlogistic potential of some ceramics needs to be taken into consideration in their clinical use.

Adsorption↗
PubMed1989

[Phosphoproteins biosynthesis induced by 1,25(OH)2D3 in the rat calvarial osteoblasts].

The present study attempts to explore the newly synthesized phosphoproteins secreted by osteoblast-like cells incubated with 1,25(OH)2D3. The phosphoproteins, which are non-collagenous proteins, may possess the ability to regulate bone mineral solubility. An osteoblast-enriched cell population isolated from 2 day-old rat calvaria by sequential enzymatic digestion was cultured in a defined medium containing dialized fetal calf serum protein (FCSP, 2 mg/ml) with 1, 5 and 10 x 10(-9)M 1,25(OH)2D3. At confluence, 32Pi (Na2H32PO4, NEX-011) was added for 24 hr. The medium proteins were precipitated by cold 10% TCA, dissolved in 15 mM Tris-HCl, pH 7.4 containing 7 M urea and chromatographed on hydroxyapatite columns (Bio-Rad, HTP). After stepwise elution with 6 mM, 0.1, 0.5 and 1.5 M Pi Hepes buffer pH 7.4 containing 3 M urea and 5 mM levamisole, the phosphoproteins were applied to 10% SDS-PAGE and autoradiographed. The 32Pi incorporated phosphoproteins of 75K, 66K, 58K, 42K, 38K, 24K, 22K, 19K, 15.5K, 13K and 3.5-10K molecular weight which were bound on a hydroxyapatite column were identified on autoradiograms of SDS-PAGE. The synthesis of 19K phosphoprotein was stable. However the synthesis of 75K, 66K, 38K and 15.5K phosphoproteins were increased by 1,25(OH)2D3. Therefore, 1,25(OH)2D3 induced phosphoproteins synthesized in rat calvarial osteoblasts, which can bind tightly on hydroxyapatite, may regulate the solubility of bone mineral and play a role in maintaining a blood/bone equilibrium.

Alkaline Phosphatase↗
PubMed1988

Alterations of glomerular basement membrane relevant to haematuria.

To elucidate the morphological basis of glomerular haematuria, morphometric analysis of the glomerular basement membrane (GBM) and lamina densa (LD) was performed on silver impregnated samples for electron microscopy. The cases studied consisted of 3 groups: group A, normal controls, being from donors for kidney transplantation; group B, haematuric; and group C, non-haematuric cases with isolated proteinuria. Qualitative analysis revealed that gap formation, splitting, segmental and diffuse thinning of the GBM occur preferentially in haematuric cases. The morphometry of the GBM and LD yielded increased mean values of the GBM and of LD thickness in groups B and C. The coefficient of variation (CV, SD/mean) for the GBM and LD, however, was the highest in group B among the 3 groups, suggesting the most irregular GBM and LD in group B. In addition, CV was significantly higher in cases with splitting, segmental attenuation and gap of the GBM than cases without. The findings suggest that the irregularity of the GBM rather than its mean thickness is clearly associated with splitting and ultimately with haematuria via the gaps produced.

Adult↗
PubMed1988

Inhibitory effect of lysozyme on the intraglomerular immune complex formation in lupus mice.

The effect of lysozyme on intraglomerular immune complex deposition was examined in NZB/W F1 mice undergoing unilateral nephrectomy. Unilateral nephrectomy enhanced the glomerular immune complex deposition and glomerular lesions, which were suppressed by repeated intraperitoneal injections of lysozyme, in spite of unaltered serum anti-DNA antibody titers. DNA binding to the glomerular basement membrane (GBM) examined in vitro and that to glomeruli examined in vitro were also suppressed by lysozyme. An increased survival rate and decreased proteinuria were also induced by this basic protein. The mechanisms of the ameliorative effect were studied in vitro. DNA was bound to the GBM only in the presence of serum, plasma, or fibronectin. A similar inhibitory effect on DNA binding was also obtained by another polycation, hexadimethrine, in place of lysozyme. The in vitro findings suggest that DNA binding to the GBM is mediated by fibronectin, and that lysozyme electrostatically inhibits this binding, thereby possibly reducing the in situ DNA-anti-DNA complex formation in the GBM.

Albuminuria↗
PubMed1988

Chondrosarcoma of the mandible. Report of case and a survey of 23 cases in the Japanese literature.

A huge chondrosarcoma of the mandible (80 X 95 X 100 mm in size) with extension into the infratemporal fossa is described. The tumour was successfully treated by surgical removal and postoperative irradiation. A survey of the Japanese literature revealed 23 cases of chondrosarcoma with involvement of the mandible. The tumours occurred equally in males and females whose mean age was 38 years. The molar region was the site of predilection. The most common symptom was swelling and it was accompanied by pain in 7 cases and paraesthesia in 5 cases. Radiographically, the lesions were quite variable and with the exception of 3 cases in which information was not available, they consisted of a combination of irregular radiopacity and radiolucency in 9 cases, whereas the predominant feature was radiopacity in 6 cases and radiolucency in 4 cases. There was no radiographical abnormality in 2 cases. Root resorption of adjacent teeth was noted in 3 of 6 cases where information existed. Computed tomography was thought to be quite valuable in determining the nature and extent of the tumour. Although an elevation of serum alkaline phosphatase was observed in our case, results of laboratory tests were mostly of no diagnostic significance. Surgical removal was employed in 22 cases alone or in conjunction with irradiation and/or chemotherapy. Of 14 cases on whom information was available, local recurrence occurred in 6 cases in which radiotherapy was not given and distant metastasis in 2 of 10 cases on whom information was available. Of 20 patients on whom information was available on the postoperative course, 7 patients died 5 months to 6 years after the primary treatment.

Adult↗
PubMed1988

Malignant paraganglioma. Report of a case and review of the Japanese literature.

An unusual case of malignant paraganglioma that manifested itself as pain in the temporomandibular joint and trismus and later manifested itself as a rapidly growing neck mass is described. Computed tomography revealed a huge mass with upward and downward extension in the infratemporal fossa. Radiotherapy was completely ineffective. At autopsy, a malignant paraganglioma with multiple metastases was found, but the site of origin could not be determined because of the size and extent. One hundred and ninety-one cases of paraganglioma of the head and neck published in the Japanese literature were analyzed with regard to their site, clinical, radiographic and microscopic features as well as treatment and results.

Adult↗
PubMed1988

Treatment of "idiopathic midline destructive disease" by irradiation. A case report.

An unusual case with an aggressive destructive granulomatous lesion of the maxilla is reported. Although the possibility of infection and neoplasm could be ruled out, a definite diagnosis could not be established even by repeated biopsies which showed the lesion to be a non-specific inflammatory process. Since Wegener's granulomatosis was most unlikely, the patient was treated by radiotherapy which caused rapid remission of the lesion with no sign of recurrence after 4 years. The clinical and histological findings as well as the responsiveness to the treatment were most indicative of idiopathic midline destructive disease. Effective management of lethal midline granuloma of unknown aetiology is discussed.

Aged↗
PubMed1988

Glomerular refractoriness to contractile stimuli in rabbits recovering from ischemic acute renal failure.

The present work was performed on uninephrectomized rabbits recovering from ischemic acute renal failure (ARF) in an attempt to elucidate whether or not intraglomerular events are a determinant factor in the development of resistance to ARF. 14 days after a 2-hour clamping of the renal artery (the recovery phase), the animals did not show resistance to an additional ischemia. On the other hand, glomeruli derived from normal kidneys displayed a contractile response to angiotensin II, arginine vasopressin or norepinephrine in Eagle's minimum essential medium, whereas glomeruli from rabbits recovering from ischemic ARF were refractory to the vasoconstrictor agents. The findings suggest that glomerular refractoriness to contractile stimuli does not provide resistance to an additional renal ischemia in the ischemic model of ARF.

Acute Kidney Injury↗
PubMed1988

Prolonged inflammatory reactions induced by artificial ceramics in the rat air pouch model.

The male Sprague-Dawley rat subcutaneous air pouch was used to study the inflammatory potential of artificial ceramics that are used in joint replacement surgery. Local leukocyte influx, proteinase, prostaglandin E2 (PGE2) and tumor necrosis factor (TNF) levels were measured after injection of hydroxyapatite type I 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) was a negative control. The response was monitored over 168 h 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 elicited less response. The peak response with HAP, TCP and GC often appeared later than with MSU. TNF activity was significantly detected only after ceramics and not after MSU. The chronic and relatively prolonged reaction to some ceramics suggests that an inflammatory reaction may be seen after human implantation of these ceramics. The increased levels of TNF and production of PGE2, which is one substance proposed to contribute to bone lysis associated with loosening, are of special interest.

Air↗
PubMed1988

Glycolipids of rat glomerular mesangial cells: antibody against the cells reacts specifically to isoglobotetraosylceramide.

Cultured rat glomerular mesangial cells had relatively simple glycolipid composition which comprised mainly monoglycosylceramide, diglycosylceramide, isoglobotetraosylceramide and GM3. Beside these glycolipids, sulfatide, polar gangliosides and an unknown neutral glycolipid were detected in whole kidney and tubules. Polyclonal antibody against the cultured rat mesangial cells, which induced glomerular injury in vivo, bound specifically with isoglobotetraosylceramide.

Animals↗