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Biomedical subjects

Kazuhiro Aoki

Publications and source records attributed to Kazuhiro Aoki.

44 records · Page 3Linked to original sources

[Outcome of surgery for bilateral third nerve disorder].

PURPOSE: To review the outcome of surgery for bilateral third nerve palsy. CASES AND METHODS: The series comprised 16 cases. The eye deviation in the primary position averaged -27.0 degrees horizontally. Surgery was aimed at bringing both eyes into alignment in the primary position by recession-resection of the horizontal muscles. Transposition of the superior oblique was performed for complete third nerve palsy. Surgery was initially performed on the nonfixating eye. The fellow eye received further surgery for residual disorders. RESULTS: Within 6 months after surgery, the eye deviation in the primary position averaged -0.7 degrees horizontally. After longer follow-up, the eye deviation averaged -4.7 degrees horizontally. Postoperatively, diplopia in the primary position was absent in 11 and present in 5 cases. CONCLUSION: Surgery for bilateral third nerve paresis or palsy induced lasting cosmetic or functional improvements in the majority of cases.

Adult↗

Gene expression of bone matrix proteins in a calcified tissue appeared in subcutaneously transplanted rat dental pulp.

Dental pulp self-mineralizes or induces calcified tissue formation, when it is subcutaneously transplanted. This study aims to clarify the nature and process of this tissue calcification by using histochemical techniques and in situ hybridization methods. The dental pulps of incisors from Sprague-Dawley strain rats were homogeneously transplanted into the subcutaneous tissue of the head of another rat. On the 1st day of transplantation, the mRNAs of type I collagen (COL I) and bone sialoprotein (BSP) were expressed in the transplant. On the 5th to 7th days after transplantation, von Kossa-positive, calcified tissues appeared in the transplanted tissues. The mRNAs of COL I, BSP and osteopontin (OPN) were expressed with the same distributions as those of the von Kossa-positive areas, but those of type II collagen (COL II) and bone morphogenic protein 2 (BMP-2) were not expressed in the transplant. When the cellular incorporation of BrdU was examined after its subcutaneous injection into the animals, positive cells were present in the von Kossa-positive calcified foci as well as in their surrounding areas. These results indicate that the transplanted dental pulp possesses the ability to induce cell proliferation resulting in the synthesis of several bone matrix proteins and the formation of calcified tissue. This may give us an insight into the nature and processes of pulp obliteration, which occurs in a human tooth following an episode of trauma.

Animals↗

High extracellular calcium affects osteoclastogenesis in mouse bone marrow cell culture.

The effects of high extracellular calcium (high Ca) in the local microenvironment on osteoclasts, osteoclast progenitors and stromal cells are not fully understood. We examined high Ca effect on osteoclastogenesis in mouse bone marrow cell culture. Mouse bone marrow cells were cultured for up to 6 days in the medium supplemented with 1, 25(OH)2 vitamin D3 (D3). High Ca treatment at the early stage of culture (the initial 24 hours) reduced the number of tartrate resistant acid phosphatase-positive multinuclear cells (TRAP(+)MNCs). This treatment slightly up-regulated the mRNA expressions of receptor activator of NF-(B ligand (RANKL), RANK and osteoprotegerin (OPG). This inhibitory effect on the formation of TRAP(+)MNCs was recovered by RANKL. In contrast, high Ca treatment at the later stage of osteoclastogenesis (the last 2 days of culture) stimulated the formation of TRAP(+)MNCs, increased RANKL and RANK mRNA expressions and decreased OPG mRNA. High Ca at neither the early nor the later stage of culture affected the total number of adherent cells and the mRNA expression of alkaline phosphatase and osteopontin. In conclusion, high Ca affects osteoclastogenesis in a manner depending on the stage of osteoclastogenesis, which is partly mediated via the RANKL-RANK-OPG regulatory system.

Acid Phosphatase↗

[The drug treatment for bone resorption in the oral area].

The bone resorption in the oral area can be divided into the inflammatory and the metabolic bone resorption. In this review, we show a possibility for drug treatment in oral area, focusing on the drug development of TNF antagonist which inhibits the actions of both TNF-alpha and RANKL; the cytokines which have a critical role in the inflammatory bone resorption.

English Abstract↗

Characterization by denaturing gradient gel electrophoresis of bacterial communities in deep groundwater at the Kamaishi Mine, Japan.

Bacterial communities in groundwater collected from five different sites at the Kamaishi Mine were investigated by using denaturing gradient gel electrophoresis (DGGE). The bacterial cells in groundwater were collected on Millipore filters, and their nucleic acid was extracted by freeze-thaw cycles. A partial 16S rRNA gene was amplified by using a universal primer set by PCR. The PCR products were analyzed by DGGE. The band pattern of DGGE was essentially identical between two samples obtained from different depths in the same borehole (KH-1). Samples from the other sites differed from one another. The partial sequences of 16S rRNA genes (about 350 base pairs) isolated from bands were determined and analyzed for phylogenetic position. Almost half the sequences from two samples of the KH-1 belonged to the cluster of spore-forming, gram-positive sulfate reducer, Desulfotomaculum. The other bands also were related to those of obligate anaerobes. This suggests that the environment in both sites of KH-1 was highly anaerobic. Although only a few sequences were retrieved from the other sites, they were phylogenetically distanced from known isolates.

Journal Article↗

Outcome of surgery for bilateral third nerve palsy.

PURPOSE: To review the outcome of surgery for bilateral third nerve palsy. METHODS: The series comprised 16 cases. The eye deviation in the primary position averaged -27.0 degrees horizontally. Surgery was aimed at bringing both eyes into alignment in the primary position by recession-resection of horizontal muscles. Transposition of the superior oblique was performed for complete third nerve palsy. Surgery was initially performed on the nonfixating eye. The fellow eye underwent further surgery for residual disorders. RESULTS: Within 6 months after surgery, the eye deviation in the primary position averaged -0.7 degrees horizontally. After longer follow-up, the eye deviation averaged -4.7 degrees horizontally. Postoperatively, diplopia in the primary position was absent in 11 and remained in 5 cases. CONCLUSION: Surgery for bilateral third nerve paresis or palsy achieved lasting cosmetic or functional improvements in the majority of cases.

Adult↗

Physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination in vivo.

This study evaluated the physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination. The artificially demineralized dentin was produced on 84 monkey teeth using a decalcifying solution. Half the samples were left open to the oral cavity for one week, then, all cavities were restored with two glass-ionomer cements: Fuji IX or Fuji II LC improved (n = 7). The nanohardness of the artificially demineralized dentin at 3, 90 and 360 days was measured using a nanoindentation tester (ENT-1100, Elionix) and compared statistically by two-way ANOVA and Fisher's PLSD test (p < 0.05). Each mineral (Ca, Mg, P, F) within the demineralized dentin was also analyzed using Electron Probe Microanalysis. For the samples, the mean nanohardness of the three-day samples was significantly lower than the 360-day samples (p < 0.05). Although there was no significant difference in the mean nanohardness within all the bacterially-contaminated groups through the experimental periods (p > 0.05), the mean nanohardness of the bacterial-contaminated samples were significantly lower than the non-bacteria-contaminated samples (p < 0.05). From the EPMA results, fluoride release from both cements to the bottom of the artificially demineralized dentin was detected within three days. Although Ca density was sparse within this demineralized dentin lesion, for the Fuji IX sample, a high Mg density within this lesion was detected at 360 days.

Analysis of Variance↗