The expressions of insulin-like growth factors, their receptors, and binding proteins are related to the mechanism regulating masseter muscle mass in the rat.

OBJECTIVE: The mechanism regulating skeletal muscle mass is unclear. The purpose of the present study was to investigate the extent to which insulin-like growth factors (IGFs), their receptors (IGFRs), and binding proteins (IGFBPs) are involved in the regulation of skeletal muscle mass. DESIGN: We measured the mRNA expression levels for IGFs, IGFRs, and IGFBPs in the rat masseter muscle hypertrophied by oral administration of clenbuterol for 3 weeks and determined the correlations between the weight of masseter muscle and the mRNA expression levels. RESULTS: The mRNA expression levels for IGF-I and II, IGFR1 and 2, and IGFBP4 and 6 showed clenbuterol-induced elevations and positive correlations with the weight of masseter muscle. That for IGFBP3 only exhibited a clenbuterol-induced decrease and a strong negative correlation with the weight of masseter muscle. The mRNA expression levels for IGFBP2 and 5 showed no significant changes between the control and clenbuterol groups, and no significant correlations. IGFBP1 mRNA was not detectable. CONCLUSION: These results suggest that IGF-I, II, IGFR1 and 2, and IGFBP3, 4 and 6 are related to the mechanism regulating masseter muscle mass in the rat.

EB3, a novel member of the EB1 family preferentially expressed in the central nervous system, binds to a CNS-specific APC homologue.

APCL, a homologue of the adenomatous polyposis coli (APC) tumor suppressor, can deplete cytoplasmic beta-catenin like APC. However, as its biological function remains unclear, we have been using a yeast two-hybrid system to search for proteins that associate with its carboxyl region. Among several cDNA clones we isolated from a fetal-brain cDNA library as candidates, six included an identical sequence with significant homology to EB1, a protein known to bind to APC. The full-length cDNA of this novel homologue of EB1, named EB3, encoded a protein of 282 amino acids with 54% identity to EB1, and it was expressed preferentially in brain tissue on Northern blots. Confocal microscopy demonstrated that exogenous EB3, like EB1, is associated with the cytoplasmic microtubule network. Moreover, in these experiments EB3 and APCL appeared together in the perinucleus and the cytoplasmic microtubule network. Since APCL is also expressed highly and specifically in the central nervous system, APCL-EB3 interaction may be specific to the CNS, possibly involving stability and/or extension of microtubules during neuritogenesis.

APCL, a central nervous system-specific homologue of adenomatous polyposis coli tumor suppressor, binds to p53-binding protein 2 and translocates it to the perinucleus.

APCL, a central nervous system-specific sequence homologue of the adenomatous polyposis coli tumor suppressor, can regulate the cytoplasmic level of beta-catenin as the adenomatous polyposis coli tumor suppressor does, but its overall biological function remains unclear. Using a yeast two-hybrid system, we attempted to isolate proteins that might associate with the unique COOH-terminus of APCL. Among 166 cDNA clones isolated from a human fetal-brain cDNA library as candidates for interaction with APCL, 32 encoded parts of p53-binding protein 2 (53BP2), a molecule that interacts with p53 and Bcl2. An in vitro binding assay indicated that the Src-homology-3 domain and the ankyrin-repeat domain of 53BP2 were both required for binding to the COOH-terminus of APCL. Confocal microscopy showed that APCL and 53BP2 proteins were localized together in the perinuclei of normal mammalian cells, but this was not the case in cells that expressed truncated APCL and 53BP2 proteins. These findings suggested that binding of the COOH-terminus of APCL to 53BP2 regulates the cytoplasmic location of 53BP2. Because 53BP2 also interacts with p53 and Bcl2 and regulates p53 function, our results suggest that APCL might be involved in the p53/Bcl2-linked pathway of cell-cycle progression and cell death.

[Clinical study on the prognosis of complete denture wearers covering 10 years. 4. Masticatory efficiency].

The purpose of this study was to estimate masticatory efficiency of complete denture wearers. The subjects were 72 patients, treated before 5-10 years at students' clinic of Tsurumi University, School of Dental Medicine. The masticatory efficiencies with peanuts and Kamaboko were calculated. Results 1. The mean masticatory efficiency with peanuts for 63 patients was 35.8%, and with Kamaboko (steamed fishpast) for 64 patients was 94.5%, in comparison with natural dentition. 2. The mean masticatory efficiency with peanuts was 124.3%, and with Kamaboko was 99.6%, for complete denture wearers. 3. Comparing the measured value of masticatory efficiency with 5 to 10 years wearing period, there was significant difference in the masticatory efficiency between peanuts and Kamaboko. 4. There was significant difference in the masticatory efficiency with peanuts between the group needed new denture and the group not needed but there was not significant difference with Kamaboko.

[Clinical evaluation of the metal-based denture using superplastic titanium alloy for upper edentulous patients].

The purpose of this study was to evaluate clinically superplastic titanium alloy for maxillary complete denture. The subjects that were the 30 patients with upper edentulous ridges were selected from Tsurumi University Dental Hospital. 17 patients were maxillary and mandibular edentulous, the other patients were only maxillary edentulous. Each of metal base was made of 90 Ti-6 Al-4 V alloy by Sankin Dental Co.. The portion of a resin was used of PMMA resin with 4-META (4-methacryloxyethyl trimellitic anhydride). At the time of inserting the denture and one month after, the dentures were clinically observed about the retentive force and the adhesive condition on finish line. At the same time, the patients were examined oral mucose and inquired of the feeling relating to wear new denture. Furthermore each weight of new dentures was compared with each of old dentures. The results were as following: 1. The width and depth of the palate were measured previously on posterior palatal sealed area. The mean value of the depth was 8.8 +/- 1.8 mm and the mean value of the width was 44.9 +/- 2.7 mm. 2. The retentive force of new dentures was clinically adequate enough to achievement of function without two cases. 3. The adhesive condition on the finish line was adequate in all cases. 4. The mean weight value of the new denture was 20.1 +/- 3.9 g. 5. 2 of 30 patients were finded the slightly redness without pain on the middle palatal mucose. 6. The feelings of patients relating to wear were as following: 1) Lighter than old denture. 2) More extensive tongue space.(ABSTRACT TRUNCATED AT 250 WORDS)

[Solvent power of new denture cleaner for denture calculus and the influence of this cleaner on the denture materials].

In order to chemically remove the calculus adhering to a denture, new denture cleaner was prepared on an experimental basis. The principal ingredient of this solution was a chilating agent which contained the phosphoric acid. This study consisted of the fundamental and the clinical examinations of this solution the purpose of which was to test the solvent power of this solution on the calculus and to evaluate its influence on the denture materials and its effectiveness in clinical practice. 1. the fundamental study 1) method (1) The test for the solvent power of this solution. The powder of tricalcium phosphate (T.C.P. powder: Wakohjunyaku Co.) was substituted for the calculus adhering to a denture. (1) The influence of the solution temperature on the solvent power. The T.C.P. powder was dissolved at 20 degrees C, 30 degrees C, 40 degrees C, 50 degrees C and 60 degrees C temperature in 10 g of the solution within 10 minutes and the amount of dissolved powder was weighted. The time was measured with a stop watch (Seiko Co.) until 0.5 g of T.C.P. powder had been dissolved in 10 g of the solution. (2) The effect of using it with an ultrasonic cleaner. The time to dissolve 0.1 g of T.C.P. powder in 10 g of this solution was compared with that of the 15% EDTA solution. The measurement was repeated 5 times and the arithmetic mean of the 5 sample values was calculated in order to show the experimental results. The room temperature was 19 +/- 2 degrees C, the humidity was 56 +/- 3%. (2) The influence of this solution on the denture materials. (1) resin specimen. In order to test the transverse strength, transverse deflection, Young's modulus and Knoop hardness, resin specimens were processed in the manner specified in I.S.O. 1567. The data were compared the resin specimens steeped in this solution and with the control sample that was steeped in water. The specimens were immersed up to 24 hours. Furthermore the existence of tarnish was observed with a 40 times microscope. (2) metal specimen. In order to test the corrosion, metal specimens were produced according to the manner of a corrosion test. The metal specimens were held vertically and the end immersed to 20 mm in this solution for 24 hours and 120 hours each. After steeping, each specimen was measured for loss in weight. The data were calculated as the loss in weight per hour (mg/cm) and the depth of corrosion per year (mm/yr).(ABSTRACT TRUNCATED AT 400 WORDS)

[Development of a new system for measuring the mean film thickness of the white silicone on the fitness test of the denture base].

A new system is developed for measuring the mean film thickness of the white silicone on the fitness test of the denture base. This system is based on analysing the B/W film density replaced from the thickness of the silicone. The detective feature of this system is as follows: 1. An adequate correlation between the logarithm of the thickness of the white silicone and the logarithm of the B/W film density was estimated from the results of experimental values. 2. With use of the computer assembled into the system, it is capable to quickly process data. 3. Compared with the conventional method, the proper suggestion was gotten to the clinical data. 4. The system is available to use of investigating the bite force and the mean film thickness of the white silicone.

[Clinical study on the prognosis of complete denture wearers covering 10 years. 3. Fitness test of the complete denture base].

The purpose of this study was to estimate the clinical condition of complete denture wearers. 72 patients came to our Dental Hospital according to our recall. The examination consisted of a questionnaire and clinical examinations. For objective evaluation, the fitness test of lower complete denture base was taken place and was classified into four groups by the thickness of the white-silicone film (A-zone 0-30 microns, B-zone 30-70 microns, C-zone 70-130 microns, D-zone 130 microns-). Results 1. The average ratio of four groups of the white-silicone film were A-zone 9.3%, B-zone 35.8%, C-zone 24.5% and D-zone 30.4%. 2. The fitness of anterior portion was ill fit in comparison with posterior portion. 3. There was statistically significant difference between the fitness of lower complete denture and dentist's judgment diagnosed as ill fit denture. 4. There was significant difference between the fitness test and the patients who complained about loose fit of the denture.