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Volume 60 (1993)
- Issue 4 Pages 429-
- Issue 3 Pages 327-
- Issue 2 Pages 249-
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Volume 60, Issue 3
Displaying 1-11 of 11 articles from this issue
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Shuichi Nozaki1993 Volume 60 Issue 3 Pages 327-343
Published: 1993
Released on J-STAGE: October 27, 2010
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Noritaka Inaba1993 Volume 60 Issue 3 Pages 344-358
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe effects of stimulation of the lateral pterygoid (LP) nerve on the contralateral LP motoneurons (Mns) were investigated in the decerebrate guinea pig.
1. Stimulation of the LP nerve induced a hyperpolarizing potential (HP) in the contralateral LP Mn. The onset and peak latency of this HP were 2.14ms and 4.10ms in 11 LP Mns on the average, respectively. The HP was reversed to a depolarizing potential after intracellular Cl- injection, indicating that it mainly consisted of IPSPs.
2. The antidoromically evoked field potential (AFP) in the LP Mn pool was depressed by the stimulation of the contralateral LP nerve. The threshold intensity was about 1.2 times the LP nerve threshold.
3. The crossed depression of AFP was significantly diminished after the destruction of the caudal part of the contralateral trigeminal mesencephalic nucleus, but not by the lesion of the trigeminal spinal tract.
4. The most rostral level in the trigeminal spinal tract nucleus, where the HRP-labelled axon terminals were found after its injection into the LP muscle, was located caudally to the lesion of the spinal tract. It is concluded that the muscle spindle afferents from the LP muscle are involved in the crossed inhibition of the LP Mns evoked by the stimulation of the LP nerve.View full abstractDownload PDF (6283K) -
Takeo Ohmura1993 Volume 60 Issue 3 Pages 359-371
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSA new cell line (VMCs) was established from the mouse calvarial cells transfected with the plasmid (pMT1-neo) containing a SV40 large T antigen gene and neomycin-resistance gene. The VMCs cell has been subcultured weekly for over 100 passages at the ratio of 1: 20-1: 60. Their population doubling time was about 15 hours. The VMCs cell seemed to be fibroblast-like monomorphic cells by a phase-contrast microscope.
The cells were examined and characterized as osteoblastic features by alkaline phos-phatase activity, bone formation in diffusion chamber and the expression of mRNAs of type I collagen and osteopontin. The features were as follows:
1. Alkaline phosphatase activity of the VMCs cell was low in growth phase but was increased by the treatment with retinoic acid.
2. Differentiation of the VMCs cell was examined by diffusion chamber implanted intraperitoneally into Balb/c mouse. Implants were sectioned and stained with hematoxylin-eosin, alizarin red S, von KÓssa, alcian blue or Azan. In the chambers formation of mineralized matrices and collagenous fibrils were observed.
3. Northern analysis demonstrated the expression of type I collagen and osteopontin mRNAs. Osteopontin mRNA was increased by the treatment with lα, 25 (OH) 2D3 or retinoic acid.
These results suggest that the VMCs cell have some properties of the osteoblast and consider to be useful for the study of bone formation and the biocompatibility test for the dental or medical materials.View full abstractDownload PDF (9324K) -
Scanning Electron Microscopic Observation and Electron Probe Microanalysis on Crown SurfacesHideo Hani1993 Volume 60 Issue 3 Pages 372-397
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSIn order to study the changes of the intraoral metals, the surface condition and composition of the crowns removed from mouths were analyzed by SEM and EPMA. Thirty-four samples were categorized into four types of alloys. Corrosive changes were evaluated by comparing the analysis results between the crown surface and its fresh sectioned surface, and also with the data from former studies.
1. Changes observed in the Au alloys were slight compared to the other three types, both in surface feature and composition, except for a slight decreace in Cu.
2. In some Au-Ag-Pd alloys, nearly no dissolution was evident. Composition changes were small, with a slight decrease in Ag and relative increase in Pd.
3. The greatest changes were observed in the Ag-Sn-Zn alloys and Ag-In alloys, even with short intraoral usage period. Generally, their surfaces were rough, with thick layers of organic materials. The dendritic structure was distinct, and dissolution between each dendrite was observed.
4. Many of the Ni-Cr alloys presented dendritic structure with dissolution. Decrease in Ni and relative increase in Si and Cr were observed.
5. Corrosive changes showed a close resemblance to the results obtained by the conven-tional basic tests. However, there were some features which did not coincide, depending on the types of alloys.View full abstractDownload PDF (20178K) -
Keiichi Ohya, Maki Sumikawa, Hideaki Ogura1993 Volume 60 Issue 3 Pages 398-407
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe confocal laser scanning microscope (CLSM) is the most recently doveloped micro-scope using the confocal system and laser light source. This microscope is possible to create optical sectioning images from any depth of the specimen. In this study, the incorporation of rhodamine-labeled albumin (R-ALB) into the bone and incisor dentin was observed by CLSM. Male Japanese white rabbits were given an intravenous injection of R-ALB every two days for 10 days and sacrificed 3 days after the last injection. Transverse ground section of the tibia about 80 μm thickness showed the incorporation of orange-red fluorescence labeling into the endosteal surface as well as the Haversian system of bone. Each labeling line of R-ALB was clearly visible by CLSM compared with the normal fluorescence image. Three-dimensional reconstruction of the sectioning images showed the process of the incorporation of R-ALB into the bone and the complexity of the labeled pattern. R-ALB was incorporated into the incisor dentin and showed the periodic labeling pattern. The high resolution image of the periodic labeling pattern was observed by CLSM. These results indicated that CLSM is a valuable apparatus for studying the fluorescence labeling images of hard tissues.View full abstractDownload PDF (13064K) -
Ken-ichi Ueno, Masamichi Yoshihashi, Norihiro Sawada, Mitsumasa Nakaji ...1993 Volume 60 Issue 3 Pages 408-415
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSBacteria in the infected root canal play an important role in the progression of the periapical lesion. The purpose of the present study was to investigate the cytotoxic effects of bacteria isolated from an infected root canal on the periapical lesion. Four obligately anaerobic bacteria were isolated and their sonic extracts (SE) were prepared. The cytotoxic assay of each SE for MC3T3-E1 cell was used with respect to the morphological cell changes and [3H] -thymidine uptake. The following results were obtained :
1. Four obligately anaerobic bacteria were identified as follows :
Poiphyromonas asaccharolytica (P. a.), Fusobacterium nucleatum (F. n.), Eubacterium lentum (E. 1.), and Peptostreptococcus micros (P. m.) .
2. The protein concentrations which induced the morphological cell changes differed in each SE. The SE from P. m. caused cell abnormalities at 10μg protein/ml, F. n. and E. 1., at 30μg protein/ml, and P. a., at 100μg protein/ml.
3. The inhibition of the incorporation of [3H] -thymidine into DNA was concentration-dependent. The SE of P. a. showed less cytotoxicity than the others at lower concentrations; 3, 10, 30μg protein/ml.
The SE from F. n. had more cytotoxicity at higher concentrations; 100, 300, a g protein/ml. These results suggest that these bacterial sonic extracts have a potential to cause mor-phological cell changes and inhibit the cell proliferation in different concentrations.View full abstractDownload PDF (6361K) -
[in Japanese], [in Japanese], [in Japanese]1993 Volume 60 Issue 3 Pages 416
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (249K) -
[in Japanese], [in Japanese]1993 Volume 60 Issue 3 Pages 417
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (240K) -
[in Japanese], [in Japanese]1993 Volume 60 Issue 3 Pages 418
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (2545K) -
[in Japanese], [in Japanese]1993 Volume 60 Issue 3 Pages 419
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (211K) -
[in Japanese], [in Japanese]1993 Volume 60 Issue 3 Pages 420
Published: 1993
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (216K)
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