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Biomedical subjects

J Kawano

Publications and source records attributed to J Kawano.

At least 73 records · Page 4Linked to original sources
PubMed1989

Characterization of rat and human steroid sulfatases.

Rat and human steroid sulfatases were purified from liver and placenta, respectively, by the same procedure. The rat and human enzymes were solubilized with Triton X-100, and purified by immunoaffinity chromatography with a monoclonal antibody showing high binding activities to both the enzymes. They were further purified by high-pressure anion-exchange chromatography to compare their structural and catalytic properties. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that both enzymes had a molecular weight of 62,000. The enzymes had similar amino acid compositions and amino-terminal amino acid sequences. Significant differences of the optimum pH, Michaelis constant and maximum velocity were observed between these enzymes. The optimum pH of each enzyme varied from 6.0 to 8.0, depending on substrates and with or without Triton X-100. In detergent-free media, steroid sulfates competitively inhibited the ability of these enzymes to hydrolyze 4-nitrophenyl sulfate. In media containing Triton X-100, on the other hand, the inhibition types of the steroid sulfates on the hydrolyzing activities of the rat and human enzymes were noncompetitive- and mixed-types, respectively.

Amino Acid Sequence↗
PubMed1989

High-performance liquid chromatographic estimation of eluates from denture base polymers.

A quantitative analytical method using high-performance liquid chromatography is developed to estimate elution profiles of dental acrylic polymers used for denture bases. The method is applied to elution studies in distilled water of resins polymerized by different representative methods. Elution properties or 'leachabilities' vary depending on polymerization conditions. Methyl methacrylate, methacrylic acid and benzoic acid are eluted from autopolymerized resins at the highest eluate concentrations and are followed by heat- and microwave-polymerized resins. These results appear to be comparable to residual amounts of the eluates in resins and their cytotoxic potencies reported.

Acrylic Resins↗
PubMed1989

A monoclonal antibody to rat liver arylsulfatase C and its application in immunohistochemistry.

We purified arylsulfatase C from rat liver microsomes and prepared a monoclonal antibody (P42C2) to the purified enzyme. By SDS-PAGE and immunoblotting analysis using P42C2, the molecular weight of the purified enzyme and of the enzyme in liver and kidney microsomes were estimated at 62,000 daltons. P42C2 caused little inhibition of arylsulfatase C activity, and was bound only slightly to liver microsomes. Localization of arylsulfatase C was studied at the light and electron microscopic level by the indirect immunoperoxidase method using P42C2. In rat liver, arylsulfatase C was detected mainly in the hepatocytes, and less frequently in endothelial cells, Kupffer's cells, and Ito's cells. In rat kidney, strong staining was observed in the straight portions of the proximal tubules. The podocytes, interstitial cells, endothelial cells, and epithelial cells of Henle's thin limbs were stained faintly. By electron microscopy, arylsulfatase C was found localized on the membranes of the endoplasmic reticulum and nuclear envelopes in these cells. These immunohistochemical findings agree with the localization demonstrated by an enzyme-histochemical method which we had previously developed.

Animals↗
PubMed1989

[Temperature change during polymerization of self-curing resin for rebasing].

Maximum temperatures, time elapsed to reach them and setting times of four kinds of self-curing resins for rebasing were measured during polymerization at 37 degrees C with attention to curing conditions which might lead to the discomfort of patients in direct rebasing. The temperatures were lower and both times were longer than those of ones for making temporary crowns. When varying thickness of the resins, the maximum temperature and the setting time significantly increased depending on an increase in the thickness, although the time elapsed to reach the maximum temperature showed no difference. All values measured were remarkably influenced by pre polymer powder/monomer ratios.

Denture Bases↗
PubMed1989

[Psychological aspects of dental students in the course of clinical prosthetics].

Cornell Medical Index (CMI), Manifest Anxiety Scale (MAS) and Yatabe-Guilford Character test (Y-G test) were carried out on 165 dental students in the course of clinical prosthetics to understand the psychological changes after study in this course. According to the Y-G profile patterns, in male students, the ratio of A, B, C, D, E and F types were 12.6, 6.7, 14.8, 63.0, 2.2 and 0.007%, and in female students, 6.9, 34.5, 17.2, 34.5 and 6.9% respectively. From the results of CMI, most of the students were stable after study in this course. Psychosomatic profile patterns of CMI before study were similar to those after in both sexes. All items of CMI were decreased in males, but some items were not decreased in females. Anxiety measured by MAS was decreased in many students but was increased in some students after study in this course. These results indicate that it is necessary to be concerned with the mental as well as physical well-being in unstable students.

Adult↗
PubMed1989

[Study on air-powder abrasive system for prosthetic clinical application. 3. Bacterial adherence to the air-powder abraded metal surface].

The purpose of this study is to investigate the relation between the metal surface texture and bacterial adherence. The surface of Au-Ag-Pd alloy was treated with or without air-powder abrasion. Seven standard strains and two clinical isolates were used. The alloys were mixed with [6-3H]-thimidine labelled bacteria. The radioactivity was measured with a scintilation counter. Streptococcus sanguis and clinical isolated Bacteroides gingivalis were adhered in a larger amount to the air-powder abraded alloy surface than to nonabraded alloy surface. These results indicated that careful consideration is needed for application of air-powder abrasive system on metal crown with secondary caries and periodontal disease.

Bacterial Adhesion↗
PubMed1989

[Studies on oral sensation in patients with implant denture. 3. Ability of interdental dimension discrimination].

Interdental dimension discrimination (IDD) ability in 11 patients with implant dentures was compared with that in 10 normal dentate subjects and bridge wearers. Using a 3.0 mm diameter wire as a reference, minimum perception difference between reference wire and test wires were measured at first molar region. In discrimination of thicker wires from reference wire, IDD ability was highest in normal dentate subjects followed by bridge wearers. It was lowest in implant denture wearers. In discrimination of thinner wires from reference wire. IDD ability was highest in bridge wearers followed by normal dentate subjects. It was lowest in implant denture wearers. A so-called "directional specificity", namely, higher IDD ability between thinner wires and reference wire than between thicker wires and reference wire, was recognized in normal dentate subjects and bridge wearers. However, there was no demonstrable directional specificity in implant denture wearers. On analyzing IDD ability in individual patients of implant denture wearers. IDD of both thicker and thinner wires from reference wire were approximately the same in 3 of the patients as those in normal dentate subjects and bridge wearers. In 7 patients, IDD ability of either thicker or thinner wires from reference wire was lower compared to the two other groups. In remaining patient, IDD of both thicker and thinners wire was impaired.

Dental Implants↗
PubMed1989

[Basic studies on cutting of composite resin cores].

Filler contents, Knoop hardness, characteristics of cutting and surface texture of eight commercial composite resin cores were investigated. Two posterior composite resins and two silver alloys were used as controls. No differences were found in filler contents and Knoop hardness between the composite resin cores and posterior composite resins. In the composite resins, Knoop hardness was correlated to the filler content. The characteristics of cutting with a diamond point varied largely among materials. The composite resin cores were divided by deterioration of the characteristics of cutting into two groups. The degree of surface roughness of composite resins polished with a finishing diamond point was larger than that of the silver alloys. SEM examination revealed little differences in the composite resin surfaces cut with a diamond point but large differences in surfaces polished with a finishing diamond.

Composite Resins↗
PubMed1989

[Changes in chewing rhythm during repetitive series of mastication in normal adults as a function of time elapsed and the four basic taste stimuli].

Surface EMG activities in the masseter muscle were recorded from 8 healthy men with normal permanent dentition during habitual chewing of a small cube of synthetic cellulose sponge which had absorbed distilled water. Three parameters of chewing rhythm, viz., cycle time, duration, and interval, were shown as the respective averages of 40 measurements of the EMG traces of a masticatory series of 42 consecutive chewing strokes. Twenty-five recording sessions, in each of which the above masticatory series were repeated 10 times in a day with a 5 minutes' recess between each series, were performed on a subject during continuous 25 days. The amount of scatter in the distribution of 25 cycle time values was great at the 1st masticatory series, gradually decreased to reach a node relatively free from the dispersion at the 5th series, and then gradually increased from the 6th to 10th series. The same phenomenon was observed in all 8 subjects, although there was a small difference among them in the number of the series where the node was apparent. The average of 5 cycle time values was used to compare in the same subject the effect of chewing the cellulose sponge which had absorbed one of the 4 basic taste solutions with the effect of chewing that which had absorbed distilled water. The average value while chewing the sponge which had absorbed 1 M saccharose was significantly lower in the subjects who obtained a relatively large average value during distilled water sponge-chewing, whereas it was significantly greater in those who obtained a relatively small average value while chewing the sponge which had absorbed distilled water. The other 3 taste stimuli induced a significant increase in the average value in most subjects.

Adult↗
PubMed1989

[Antibacterial actions of denture base resin on oral bacteria].

Antibacterial action of various denture base resins on thirteen species of bacteria were studied in vitro. Antibacterial effect of 5% tannin-fluoride preparation, 5% tannic acid and 5% chlorhexidine added to resins on these thirteen bacterial species were also investigated using heat-curing denture base resins. Fresh microwave-curing resin and pour-type resin each showed an antibacterial action on one bacterial strain. Fresh self-curing resins had antibacterial actions on several bacterial strains. However, after storage in water at 37 degrees C for one week, antibacterial action of microwave-curing and pour-type resin were diminished and self-curing resins partially lost their antibacterial actions. Denture base resin containing tannin-fluoride preparation or tannic acid showed an antibacterial effect on one bacterial strain. On the other hand, denture base resin containing chlorhexidine had an antibacterial action on eleven bacterial strains. However, color and mechanical properties of the drug-containing resins were not satisfactory.

Bacteria↗
PubMed1989

Comparative bond strengths of plastic teeth to microwave-curing, heat-curing and 4-META containing denture base resins.

Bond strength of hardened plastic teeth or acrylic resin teeth to microwave-curing, conventional heat-curing and 4-META-containing denture base resins were comparatively investigated in this study. Effects of grinding and monomer coating of the tooth ridge lap were also studied. Bond strength of plastic denture teeth to microwave-curing denture base resin was slightly higher than the other two resins. With all denture base resins used, an increased bond strength was obtained with hardened plastic teeth by treatment of tooth ridge lap but not with acrylic resin teeth. However, scattering of the bond strength was reduced by treatment of tooth ridge lap in acrylic resin teeth specimens. With hardened plastic teeth specimens, fracture in the base resin was increased by monomer coating. With acrylic resin teeth specimens, no specific fracture patterns were demonstrated by treatment of tooth ridge lap. Fracture occurred mostly in the acrylic resin teeth. These results suggest that bond strength of both denture teeth to microwave-curing or 4-META-containing denture base resin was increased or solidified by grinding or monomer coating of tooth ridge lap.

Acrylic Resins↗
PubMed1989

Abrasion resistance of microwave-curing denture base resin.

This study was designed to test the abrasion resistance of microwave-curing denture base resin. We also studies the effects of surface smoothing treatment on abrasion resistance. Test resin was allowed to polymerize, and then buff polished or treated by surface smoothing. Knoop hardness was measured both prior to and following surface treatment. Then, the test material was subjected to brushing using a newly developed toothbrushing machine. Volume and surface roughness of the material were measured before and after brushing, and the surface structure of the material was examined with SEM. Microwave-curing denture base resin is equal in Knoop hardness and abrasion resistance to its conventional heat-curing counterpart, although it is smoother at the surface. The resin improved both in hardness and abrasion resistance when it underwent surface smoothing treatment regardless of whether it was heat-cured or microwave-cured. As was evident from SEM observations that both types of resins suffered superficial chipping following severe brushing, which is in accordance with our previous clinical findings.

Acrylic Resins↗
PubMed1989

[Clinical observation of bruxism-induced wear facets and the influence of wear facets on masticatory function].

The wear facets produced 10 years ago were compared with the present ones in a 35-year old patient with bruxism. The electromyographic data of 10 years ago were also compared with the current data. Current mandibular kinesiograph data were also measured. The total area of the present wear facets was increased approximately 2.3 times those of 10 years ago in the upper teeth, and approximately 2 times in the lower teeth. However, the number of current wear facets of the upper and lower teeth was reduced, compared to that of 10 years ago. The Gothic arch tracing revealed a difference of about 1 mm between the centric occlusion and the centric relation. The patient had a unilateral balanced occlusion and a grinder-type chewing pattern. The free-way space, was in a normal range, approximately 2 mm. The raw electromyographs during sponge chewing 10 years ago differed from the present findings, although the chewing rhythm was the same.

Adult↗
PubMed1989

[Relation of surface texture of fine finishing diamond point for composite resin and polished surface of composite resin].

Distribution of diamond grain size of seven fine finishing diamond points was measured by a digital image analyzer. Also influence of diamond grain size of fine finishing diamond points on finished surface of two types of visible light cured composite resins (semihybrid type and submicron filler type) were investigated. Diamond grain size was almost from 10 to 100 microns 2 in area. Diamond grain size was closely related to the surface roughness of semihybrid type composite resin, although it was not related to that of submicron filler type composite resin. Surface roughness of a submicron filler type composite resin finished at a low speed was less than that at a high speed. Grain size of diamond point and revolution speed may play an important role in surface texture of composite resin.

Composite Resins↗
PubMed1989

[Results of surgical treatment in patients aged 80 years and over].

Surgical treatments were performed in 31 patients over 80-year-old with lung cancer. Men were 25 and women were 6, the eldest patient was 92-year-old male. Pneumonectomy was carried out in 3, lobectomy in 19, carinal resection in 1, Segmentectomy in 4, and partial resection of lung in 2. Histologies of resected specimen in 31 included 11 epidermoid carcinoma, 15 adenocarcinoma and 5 other cell types. There was no patients died within 30 days postoperatively. The cumulative 5 year-survival rate was 53.9%.

Adenocarcinoma↗