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Get PDFThe kinetic properties of tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) Na+ channels in acutely dissociated neonatal rat trigeminal ganglion neurons were studied using whole-cell and cell-attached patch-clamp recordings. The time course of TTX-R currents was slower than that of TTX-S currents. Compared with TTX-S currents, TTX-R currents had more positive half-activation and half-inactivation voltages. TTX-R currents recovered from inactivation much faster than TTX-S currents. Cell-attached patch recordings showed that the slope conductance of single TTX-S and TTX-R channels was 14.6 pS and 7.8 pS, respectively. TTX-R channels had longer open-times and more dispersed latent-times than TTX-S channels. The convolution of the first latency distribution with the open-time distribution revealed that the slower time course of TTX-R currents is due to longer open-times and more dispersed latent-times of the TTX-R channels compared with those of the TTX-S channels. These findings suggest that TTX-R Na+ channels in trigeminal ganglion neurons have similar kinetic property to brain TTX-S Na+ channels, but not to structurally homologous cardiac Na+ channels.departmental bulletin pape
Get PDFThe purpose of this study was to investigate the expression of PG mRNA in human temporomandibular joint (TMJ) disks from patients with temporomandibular disorders (TMD). Total RNA was isolated from the TMJ disks. All patients had undergone diskectomy under general anethesia. RT-PCR was performed using primers for the proteoglycans, aggrecan and decorin. On electrophoresis of a lysate of human TMJ disks, decorin was recognized in each sample. In the calcified part of the disk which we recognized visually, aggrecan was also recognized. These results suggest that TMJ disks contain decorin, and are fibrous tissue. If the disk was subjected to excessive compression in addition to tension, cells similar to chondrocytes and expression of aggrecan was induced. Calcification would be initiated in the part of the disk experiencing the increased compression.departmental bulletin pape
Get PDFThis study proposes a new method for a prognostic analysis on the course of diseases. This method aims to separate, among same disease population, several prognostic groups showing different temporal patterns in the course of the disease and evaluate the influence of prognostic factors separately for each group. To do this, we develop a new temporal distribution that we call multiple component Weibull distribution, which is given by a linear combination of Weibull distributions with different shape and scale parameters. This method is applied to the prognostic analysis of cardiac death of acute myocardial infarction (AMI) during hospitalization. The subjects are the first year study population enrolled in the 5-year prospective survey conducted by the Heart Institute, Tokyo Women's University. We separated the prognosis of AMI into two prognostic groups, one with early death of initial failure type and the other with late death of weak abrasion failure type. It was found that a prognostic factor of early death, mostly caused by cardiogenic shock or cardiac failure, was Killip classification, whereas, in the late death, mostly caused by cardiac rupture or perforation, Q type MI and age other than Killip classification were found to be influential prognostic factors.departmental bulletin pape
Get PDFTo investigate the mechanism of the glucocorticoids- induced augmentation of skin response, we have recently reported the modulatory effect of glucocorticoids on the regulation of cytokines production in keratinocytes stimulated with various chemicals in vitro through both NF-κB and AP-1 activation. Further to clarify the mechanism in the glucocorticoids-induced augmentation of cytokines production from keratinocytes, we examined the effect of glucocorticoids to keratinocytes without chemical stimulation. Glucocorticoids 10–4 M inhibited the production of IL-1α from Pam 212 cells. However, lower concentration (10–8–10–10 M) of glucocorticoids significantly enhanced the production of IL-1α by Pam 212 cells at both the protein and mRNA levels. In contrast, glucocorticoids had no effect on the production of either TNF-α, IL-6, nor GM-CSF by Pam 212 cells cultured for 6 h. Electrophoretic mobility shift assays (EMSA) revealed that 10–10–10–12 M glucocorticoids induced the NF-κB activation in Pam 212 cells, however, augmented AP-1 activation by 10–8–10–10 M of glucocorticoids was observed in Pam 212 cells. Furthermore, pyrrolidine dithiocarbamate (PDTC) partially inhibited the IL-1α production and completely inhibited NF-κB expression by Pam 212 cells. On the other hand, MAP-kinase inhibitors (PD98059, SB202190) completely abrogated not only AP-1 activation but the low concentration glucocorticoids-induced IL-1α production. These data indicated that lower concentration of glucocorticoids induced the augmentation of IL-1α production from keratinocytes mediated through the AP-1 pathway and partially through NF-κB pathway.departmental bulletin pape
Get PDFDental 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.departmental bulletin pape
Get PDFAn analysis of static occlusion including occlusal force and occlusal contact area in intercuspal position may be helpful but a dynamic analysis of occlusion should be regarded as more important for analyzing the stomatognathic system. Anthropological research has shown that the Japanese and the Mongolian populations share morphological and genetic similarities, although their dietary lives are not the same. The purpose of this study was to evaluate the relationship between environmental factors such as dietary life and stomatognathic function with a dynamic analysis of physiological tooth displacement. Ten clinically healthy subjects were recruited (mean age 24.8 ±1.0 years). The subjects were divided into two groups 1) Mongolian group: five Mongolians grown with a more or less natural texture diet and 2) Japanese group: five Japanese grown with a relatively soft diet. The displacement of the upper left first molar was measured during function using a three-dimensional tooth displacement transducer Type M-3. The tooth displacement in the Japanese group occurred mostly in an apicopalatal direction, but intruded basically parallel to the tooth axis in the Mongolian group. The stress-strain curve revealed that elastic socket deformation and viscous elements were more pronounced in the Japanese group. It was concluded that environmental factors such as dietary life could influence tooth displacement during function.departmental bulletin pape
Get PDF(Object) Endovascular treatment with Guglielmi detachable coil has been developed as a less invasive treatment for cerebral aneurysm. The aim of this study is to clarify the mechanism of the preventive effect of coil embolization. (Method) Two aneurysm models were employed. One was a T-shaped bifurcation tube with a spherical dome made of glass, which was used for the measurement of pressure and visualization of flow pattern. The other model was a T-shaped glass tube with a spherical elastic silicone dome, which was used for the measurement of aneurismal wall displacement due to pulsation of flow. (Result) 1, Guglielmi detachable coil caused no change in intra-aneurismal fluid pressure. 2, Coil insertion obstructed and slowed intra-aneurismal flow. This flow stagnation in the aneurysm might promote thrombus formation. 3, With increase in numbers of coils anchored at the intra-aneurismal wall, the displacement of the wall was considerably depressed. This suggests that coil insertion decreases the stress on the aneurismal wall. (Conclusion) 1, Coil insertion depresses the pulsatile aneurysm wall movement, and diminishes the stress of the aneurysm wall. 2, Coil insertion obstructs intra-aneurismal flow and facilitates thrombus formation in the aneurysm. These two factors may operate synergistically to prevent aneurysm rupture.departmental bulletin pape
Get PDFThe purpose of this study was to investigate the effect on the vibratory characteristics of a cast hollow obturator prosthesis retainer when varying its bulb height. Bulb parts with high (H), middle (M), and low (L) lateral walls were prepared. A Vibration Generator was used to excite the three obturators, while a Laser-Doppler Vibrometer was employed to detect the vibrations at specified measurement points. The frequency response functions of each obturator were recorded on an FFT analyzer to enable their modal shapes to be identified. In addition, transient response simulations were carried out and the decay rate (DR) and the maximum amplitude (MA) of the rest and clasp parts of each obturator were obtained. These were statistically analyzed by ANOVA and Fisher's PLSD test (p < 0.01). The modal shapes were almost the same in all obturators. Significant differences were found in DR in all pairs among the three obturator prostheses, with the DR of the L type being the highest. On the other hand, there were no significant differences in MA. We conclude that the L type is preferable from the standpoint of its vibratory characteristics.departmental bulletin pape
Get PDFIt has been recognized that mandibular movements evoke head movements during jaw tapping. However there have been only a few studies that investigated the aspects of head movements during mastication. The objective of this study was to demonstrate the hypothesis that the head moves actively in mastication in order to achieve effective destruction of a food bolus. Head and mandibular movements during gum, gummi candies and kelp chewing among nine adult volunteers have been recorded as time series data with a three-dimensional motion capture system and the vertical components of the movements have been analyzed. To focus on occlusal phase of mastication, the following parameters have been examined: time lag of the head movements at the beginning of occlusal phase, perpendicular velocity of the head at the beginning of the phase of occlusion, and average velocity of the head during occlusal phase. The results showed that the head moved downward in mastication and the velocity of the head movements increased in the order of gum, gummi candies and kelp chewing. There is a possibility that the elasticity of a food bolus affects the activity of head movements, and the kinetic energy was increased to achieve effective destruction of a food bolus.departmental bulletin pape
Get PDFBiochemical modulation of 5-fluorouracil (5-FU) has been verified the evidence of significant improvement of survival and quality of life in patients with advanced colorectal carcinoma. We investigated the therapeutic and adverse drug reaction of intensive chemotherapy using cis-platin (CDDP), 5-FU and dl-leucovorin (LV) (PFL-therapy), which may be producing dual biochemical modulation effect of 5-FU for advanced colorectal carcinoma. Administration schedule was 13 mg/m2 of CDDP, 300 mg/m2 of 5-FU, and 30 mg/body of dl-LV for 5 consecutive days. This regimen was repeated at 3-week intervals in hospital. Sixteen patients were enrolled in this study, most of whom had a history of previous chemotherapy as adjuvant treatment, and the response rate was 25%, with four patients having "partial response" and eight "no change". In respect to performance status, 46% of patients who completed the protocol were markedly improved in spite of their poor performance status before treatment. Moreover, when patients were classified into two groups based on changes of the serum level of CEA, "responder in CEA level" showed better prognosis than "non-responder in CEA level". Major toxicifies were nausea, hyperglycemia and neutropenia. Three patients experienced Grade 4 hematological side effect, but these complications resolved quickly in all patients except for one patient. PFL-therapy is effective for advanced colorectal cancer with large tumor burden and showed the same prognostic result as the American and European trials in spite of smaller number of treatment cycles and a history of previous chemotherapy. We will be able to demonstrate the usefulness of this regimen for Japanese patients with advanced colorectal cancers after adding new cases to the present report.departmental bulletin pape