Resting T cells negatively regulate osteoclast generation from peripheral blood monocytes.

There is accumulating evidence that T cells may be involved in osteoclastogenesis in a variety of murine systems. However, the precise role of human T cells in the regulation of osteoclast generation is still unclear. To address this issue, we investigated the effect of resting peripheral T cells on receptor activator of NF-kappaB ligand (RANKL)-induced osteoclast generation from human peripheral monocytes. Although osteoclasts were not generated in the culture of human peripheral blood mononuclear cells (PBMC) in the presence of RANKL and macrophage colony-stimulating factor (M-CSF), the addition of cyclosporine A (CsA), a potent inhibitor of T-cell function, resulted in the formation of an increasing number of lacunae resorption on dentine, suggesting T cells may inhibit osteoclast formation. In a coculture of T cells and monocytes, which were isolated from PBMC, T cells inhibited the osteoclast generation from monocytes, as determined by tartrate-resistant acid phosphatase (TRAP) staining and a pit assay using dentine. This inhibition of osteoclast generation by T cells was also observed in a culture of the parathyroid hormone-stimulated SaOS4/3 osteoblast cell line and monocytes. The culture in Transwell plates revealed that the cell-to-cell interaction was not required for the inhibition, suggesting that T-cell cytokines may be responsible for the inhibition. Among inhibitory T-cell cytokines on osteoclastogenesis, granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-gamma (IFN-gamma) were actively produced by CD4 T cells but not CD8 T cells in the coculture of T cells with monocytes, and the neutralizing antibodies to these cytokines partially rescued the T-cell-induced inhibition of osteoclast formation. Although CsA did not affect RANKL-induced osteoclast generation in the culture of monocytes alone, it completely rescued the T-cell-induced inhibition of osteoclast formation and strongly inhibited the production of GM-CSF and IFN-gamma. Thus, we demonstrate that resting T cells negatively regulate the osteoclast generation via production of GM-CSF and IFN-gamma by CD4 T cells and that CsA stimulates the osteoclast generation through the inhibition of the production of these cytokines. These findings provide new insight into therapeutic strategies for immunosuppression-induced bone loss in transplant and other diseases.

Clinical application of a new compact computed tomography system for evaluating the outcome of regenerative therapy: a case report.

BACKGROUND: The limitations of conventional 2-dimensional (2-D) radiographs have been emphasized in many studies. Because the image is a 2-D map of the 3-dimensional (3-D) tooth and periodontal tissue, these structures may be superimposed on each other. Recently, 3-D image analysis by computed tomography (CT) was introduced to dentistry, but it has been used only rarely in the periodontal field. METHODS: The purpose of this case report was to introduce the clinical application of a newly developed, compact computed tomography system for evaluating the outcome of regenerative therapy in an adult patient with periodontitis (male, aged 55 years). To evaluate the bone defects including furcation involvement, we took an intraoral radiograph and performed CT scanning on tooth #19. We recorded a number of clinical parameters at the time of surgery. We compared the images of the bone defect obtained by CT images and the conventional radiograph with the true bone defect morphology at the surgical site. RESULTS: One year after the periodontal surgery, we again took CT scans and a conventional radiograph, and the new images of the bone defect were compared and evaluated. The new CT images were reconstructed for 3-D evaluation and compared with those taken before surgery. The CT provides 3-D images of excellent quality for evaluating the morphology of the periodontal bone defect and furcation involvement. CONCLUSIONS: We consider that CT is a useful aid in periodontal examination and diagnosis, and in the prediction and evaluation of periodontal treatment outcomes.

Ortho cubic super-high resolution computed tomography: a new radiographic technique with application to the temporomandibular joint.

OBJECTIVE: The purpose of this study was to present a newly developed ortho cubic super-high resolution computerized radiographic technique (Ortho-CT) and its application to the temporomandibular joint. METHOD AND PATIENTS: A prototype was assembled on a Scanora (Soredex Findent Co) with the use of a 4-inch image intensifier instead of film. Data were collected from a single 360 degrees scan and a cylinder 32 mm in height and 38 mm in diameter. Images were reconstructed with a software program on a personal computer. Imaging data consisted of 240 (height) x 280 (diameter) cubic voxels, each with a dimension of 0.136 mm. With this small voxel size, the image resolution was high and was the same in any direction. Three patients with temporomandibular joint disease (trauma, pain and dysfunction, fibroosseous ankylosis) were evaluated with Ortho-CT, and the images were compared to routine radiographic films. CONCLUSION: Preliminary clinical experience with Ortho-CT demonstrates subjectively superior image quality compared to panoramic and conventional tomographic images. The images were similar to conventional computed tomography, but this new radiographic technique is less expensive, takes less space, and gives a lesser patient dose.

Diagnostic efficacy of three-dimensional images by helical CT for lesions in the maxillofacial region.

The purpose of this study was to evaluate the efficacy of three-dimensional (3-D) images produced with a helical CT for the diagnosis of lesions occurring in the maxillofacial region. Thirty-four patients, who had lesions in the maxillofacial region, were examined by plain radiography (intra and extraoral) and the helical CT. Further, 3-D images were reconstructed from the data provided by the helical CT using the volume rendering method. These images were compared with plain radiographic images and conventional two-dimensional (2-D) CT images in terms of the information they provided for diagnosis. Using the 3-D images for tumors, bone destruction, inner components, extent of the lesion,the relationship between the lesion and surrounding anatomical landmarks, and the roots of the adjacent teeth were observed in overall views. We conclude that 3-D images produced by helical CT may provide useful information for the diagnosis of lesions.

Development of X-ray TV M-mode and reconstructed ultrasound M-mode methods for investigating tongue movement during swallowing in humans.

There were two purposes of this study. The first purpose was to introduce the "X-ray TV M-mode waveform" which is reconstructed from sequential X-ray TV images and the "reconstructed ultrasound M-mode waveform" which is delivered from ultrasound B-mode images. The second purpose was to evaluate the usefulness of these two types of waveforms in the investigation of tongue movement during swallowing. The instrument system employed in this study consisted of ultrasound and X-ray TV synchronized by a time marker. After the X-ray images and ultrasound B-mode images were recorded on an optical disk, X-ray TV M-mode waveform and ultrasound M-mode waveform were reconstructed using an MC 68030/OS-9 computer. No significant differences in quality of images were observed between the X-ray TV M-mode waveform and the reconstructed ultrasound M-mode waveform. Therefore, both waveforms of the X-ray TV M-mode and the reconstructed ultrasound M-mode are equally useful in measuring tongue movement.

[Effects of cepharanthine on liposomal permeability and size].

Effects of cepharanthine, one of membrane-stabilizing agents, on membrane permeability and on liposomal size were examined. When cepharanthine was added to the lipid before liposome formation, the size of liposome increased and the permeability did not change. On the other hand, when cepharanthine was added to the liposome suspension after liposome formation, no effect was found on liposomal size but the membrane permeability increased and lag time of initial leak of 5 (& 6)-carboxyfluorescein reduced dose-dependently.

Development of perioral muscle activity during suckling in infants: a cross-sectional and follow-up study.

The activity of the perioral muscles during breastfeeding in infants was investigated using EMGs. Fifty-six infants aged from 1 to 5 months were classified into five groups according to month of age in the cross-sectional study. Follow-up was carried out on 18 infants whose mean age was 2.5 months at the initial examination, and 4.8 months at the second. During suckling, EMGs were recorded unilaterally from the temporalis (TM), the masseter (MM), the orbicularis oris (OM), and the suprahyoid (SM) muscle groups. The activity of the SM increased significantly with age, while there was no appreciable increase in the activity of the TM, MM, and OM in either the cross-sectional study or the follow-up. However, total muscle activity was shown to increase significantly in both parts of the study. These findings suggest that the active tongue- and jaw-lowering movement may play a primary role in increasing sucking strength during the suckle-feeding period in infants.

Effect of phenytoin on interleukin-1 beta production in human gingival fibroblasts challenged to tumor necrosis factor alpha in vitro.

Effects and interaction of tumor necrosis factor alpha (TNF alpha) and the antiepileptic drug phenytoin (PHT) on interleukin-1 beta (IL-1 beta) production as well as on prostaglandin E2 (PGE2) formation were studied in gingival fibroblasts in vitro. TNF alpha, in contrast to PHT, dose-dependently stimulated the production of cell-associated IL-1 beta. The stimulatory effect of TNF alpha on IL-1 beta production was accompanied by enhanced PGE2 formation. When PHT and TNF alpha were added simultaneously, the drug potentiated the stimulatory effect of TNF alpha on both IL-1 beta production and PGE2 formation. The major PHT metabolite, p-HPPH, did not affect IL-1 beta production, either alone or in combination with TNF alpha. The production of IL-1 beta induced by TNF alpha and the combination of TNF alpha and PHT was further enhanced in the presence of the prostaglandin endoperoxide (PGH) synthase inhibitors, indomethacin and flurbiprofen. The PHT-mediated enhancement of TNF alpha-induced IL-1 beta production and PGE2 formation in gingival fibroblasts may be an important link in the pathogenesis of gingival overgrowth induced by PHT.

[Analysis of occlusal contacts of children by the T-Scan system. (1) The reproducibility of the sensor].

The present study was designed to discuss the reproducibility and the clinical usage of the T-Scan system in children. A plastic model of a normal permanent dentition was used for the study. The model was pressed on the sensor of the T-Scan system in maximum intercuspation under various assigned pressures (10, 20, 30, 40 and 50 kg) which were controlled by a press machine (Auto Graph AG-5000C). The pressings were made under following conditions, such as 1) the sensor handle was fixed, 2) the sensor handle was free and 3) the sensor handle was free but the maxilla arch form was marked on the sensor by the silicone impressional material. The total number of tooth contacts were counted and sagittal and the vertical distance from midline to the tooth contacts were measured. The results obtained in the present study are summarized as follows: 1) The number of tooth contacts became stable, when the pressing sensor was exercised several times. 2) The more pressure raised on the sensor, the more the number of tooth contacts increased, and the more the coefficient of variation tended to decline. 3) The arch model displayed on the T-Scan system was not exactly represented in the actual dental arch. 4) Due to the marking by silicone impressional material on the sensor, the reproducibility of the T-Scan system was further improved.

Prostaglandin E2 level in gingival crevicular fluid from patients with Down syndrome.

The levels of prostaglandin E2 (PGE2) and interleukin-1 beta (IL-1 beta) were determined in gingival crevicular fluid (GCF) collected from patients with gingivitis: 15 Down syndrome children and 15 controls. The mean level of PGE2 in GCF was significantly higher (P < 0.05) in the Down syndrome group (10.0 pg/microliters GCF) than in the control group (4.6 pg/microliters GCF). In GCF samples collected from sites characterized as noninflamed, the mean level of PGE2 was significantly higher (P < 0.001) in the Down syndrome group than in the controls. The mean level of PGE2 in samples from inflamed sites, on the other hand, did not differ between the two groups. The mean level of IL-1 beta was not significantly higher in the Down syndrome group than in the controls. This study shows that the level of PGE2 detected in GCF from Down syndrome patients is increased, a fact that may be of importance in the pathogenesis of the periodontal disease frequently seen in these patients.

Enzymatic characterization of human alpha1,3-fucosyltransferase Fuc-TVII synthesized in a B cell lymphoma cell line.

The human alpha1,3-fucosyltransferase, Fuc-TVII, a key enzyme in the biosynthesis of selectin ligands, was expressed as a soluble protein-A chimeric form in a human B cell lymphoma cell line, Namalwa KJM-1, and purified using IgG-Sepharose. The enzymatic properties of recombinant soluble Fuc-TVII were then examined. Its enzyme activity was highest at pH 7.5, and the presence of 25 mM Mn2+ was required for full activity. Fuc-TVII exhibits an acceptor specificity restricted to alpha2,3-sialylated type 2 oligosaccharides, and the apparent Km values for alpha2,3-sialyl lacto-N-neotetraose and GDP-fucose were 3.08 mM and 16.4 microM, respectively. The inhibitory effects of various nucleotides on the activity of Fuc-TVII reflected its donor specificity for the nucleotide portion of GDP. Fuc-TVII was demonstrated to be useful for the synthesis of a sialyl Lewis x hexasaccharide from lacto-N-neotetraose in combination with an alpha2, 3-sialyltransferase, ST3Gal IV. Polyethylene glycols enhanced the thermal stability of Fuc-TVII, leading to increased formation of the reaction product.

Development of a compact computed tomographic apparatus for dental use.

OBJECTIVE: To describe a compact computed tomographic apparatus (Ortho-CT) for use in dental practice. METHODS: Ortho-CT is a cone-beam-type of CT apparatus consisting of a multifunctional maxillofacial imaging machine (Scanora, Soredex, Helsinki, Finland) in which the film is replaced with an X-ray imaging intensifier (Hamamatsu Photonics, Hamamatsu, Japan). The region of image reconstruction is a cylinder 32 mm in height and 38 mm in diameter and the voxel is a 0.136-mm cube. Scanning is at 85 kV and 10 mA with a 1 mm Cu filter. The scan time is 17 s comparable with that required for rotational panoramic radiography. A single scan collects 512 sets of projection data through 360 degrees and the image is reconstructed by a personal computer. The time required for image reconstruction is about 10 min. RESULTS: The resolution limit was about 2.0 lp mm-1 and the skin entrance dose 0.62 mGy. Excellent image quality was obtained with a tissue-equivalent skull phantom: roots, periodontal ligament space, lamina dura, and cancellous bone were clearly visualized. CONCLUSION: Ortho-CT provides three-dimensional images of excellent quality for dental use at a low entrance dose.

Clinical application of a new compact CT system to assess 3-D images for the preoperative treatment planning of implants in the posterior mandible A case report.

When treatment planning before placing dental implants in the posterior region of the mandible, the locations of the inferior alveolar nerve and mental foramen need to be ascertained, as they determine the bone height available and the implant length selected. The purpose of this study was to introduce the clinical application of a newly developed compact computed tomography system (Ortho-CT) to assess three-dimensional (3-D) images for the preoperative treatment planning of implants in the posterior region of the mandible. To evaluate the 3-D images, we scanned using the Ortho-CT system the mandible with a radiopaque template placed in the posterior region. The Ortho-CT images provided excellent information for evaluating the morphology of the mandible, and for showing the location of the inferior alveolar nerve, mental foramen and the relationship of the template to the bone. We consider that Ortho-CT is a useful aid to preoperative treatment planning of implant therapy in the mandible.

[Comparisons of meter reading values in 5 electronic measuring devices].

The root apex values given in the manufacturers' introductions of 5 electronic measuring devices were compared with the mean values measured by each device in the following cases: a) The tip of file was at the apical constriction in the experimental tooth model. b) The tip of file was between 0 mm and -2.0 mm from the root apex in the vital teeth and the pulpless teeth. In the experimental tooth model, when the tip of file was at the apical constriction, the mean values measured by each device except EM were lower than the root apex values given in the manufacturers' introductions of each device. In the case of the vital tooth, when the tip of file was between 0 mm and -2.0 mm from the root apex, the mean values measured by EM-S II and EM were similar to the values given in the manufacturers' introductions of these devices, but not to those obtained by the other devices. Measurements of the pulpless tooth by each device revealed mean values lower than the values given in manufacturers' introductions for the root apex.

A case of osteoporosis with bilateral defects in the mandibular processes.

We carried out a detailed total body examination of a 62-year-old woman with osteoporosis who had bilateral defects in the mandibular processes. It was inferred that the defects in both articular heads were caused by resorption of small bone fragments following fracture. The quantity of bone salt was determined by microdensitometry, and a diagnosis of osteoporosis was then established. An improved bite was obtained by treatment consisting of tooth extraction and the preparation of partial dentures.