Nichidai koku kagaku = Nihon University journal of oral science最新文献

In order to clarify functional roles of extracellular glucosyltransferases (GTases) from S. mutans serotype c in initial stage of plaque formation, GTase-I and GTase-S were purified from culture fluids of strain PS 14. And an ability of these GTases to enhance cellular attachment of oral streptococci was investigated using 3H labeled resting cells of S. sanguis Challis and S. milleri Is 57. The results were as follows: 1) From culture fluids of strain PS 14 grown in a M 4 medium supplemented with 1% ammonium sulfate, GTase-I was purified by ammonium sulfate fractionation, CM-cellurose column chromatography and Toyopearl HW-55 gelfiltration. Also, GTase-S was purified by the method of Baba et al from the culture fluids of strain PS 14 grown in a dialyzed BHI medium. Purified GTase-I and GTase-S were almost homogeneous, and had a molecular size of 160 KDa and 145 KDa respectively (by SDS-PAGE). 2) Sucrose-dependent attachment of S. sanguis cells to experimental pellicles was markedly enhanced by the addition of crude GTase in saliva. This fact was conformed by a scanning electron microscopic observation of the attachment cells. Such enhanced attachment necessitated a long-term incubation (greater than 10 h) of the cells in the presence of sucrose, suggesting that it is correlated to de novo glucan synthesis. 3) Purified GTase-I also had an ability to enhance the cellular attachment of S. sanguis cells as well as crude GTase, while purified GTase-S didn't have. Neither crude enzyme, GTase-I nor GTase-S have an ability to enhance significantly the cellular attachment of S. milleri cells. However, S. milleri pretreated with the preparations containing GTase-S gained the ability to attach to experimental pellicles prepared from saliva supplemented with GTase-I. These results suggest that the cellular attachment system mediated by enzymatic action (s) of GTase (s) from serotype c S. mutans be present and function in the first stage of plaque formation.

Clicking sounds are one of the symptoms that appear in the temporomandibular joint dysfunction at a high rate. But they are sometimes found in healthy subjects also, so that clicking sounds are seldom recognized as an pathologic condition. Study reports on clicking sounds in the past concentrated mainly on their cause, process of their appearance and their spectral properties. These studies were, however, all based on the understanding that clicking sounds were a kind of symptom or signals that accompanied the unbalanced jaw relationship. They did not examine pathologic conditions or functional change caused by the very existence of clicking sounds. This author has been reporting on the influence of clicking sounds on hearing abilities. This time the author considered it necessary to study the cause for rise of the hearing level of the clicking subjects in relation to the unbalanced positions of their jaws. The author therefore examined the relationship between the phases of occlusal contact and hearing abilities of the clicking subjects. From the results, we obtained the following conclusions: 1. As for the frequency of appearance of clicking sounds, 28 out of the 175 healthy subjects (aged either 21 or 22) had clicking sounds on one side, accounting for 16.0%, at the hazard rate of 1%. There was no differences between the sexes and between the right and left sides. 2. Of the 37 subjects, the cases in which the centric position fall on the intercuspal position were only three among the 17 non-clicking subjects (Group I), accounting for 17.6% and none, among the 20 clicking subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

In this study, the dry skull with Multibanded appliance was employed in several tractional directions and positions for the investigation of the effects of J-hook headgear on the craniofacial complex including the palate. The traction was carried out by the tractor constructed by J-hook headgear exerting the load of 3 kg on the dry skull applied with the strain gauges. The tractor was connected to the four positions: the gingival and the incisal hooks on the archwire between the central and the lateral incisors, and onto archwire mesial to the canine and the 1 st premolar brackets. The tractional directions were five, varied from -20 degrees - (+)60 degrees to the occlusal plane at the interval of 20 degrees. The distribution of two-dimensional strain in several tractions and the effects on the craniofacial complex were investigated. The results were as follows: 1. In the right side view, the maxillary complex was not rotated when the tractional directions were set about at +40 degrees in the incisal traction, and between +40 degrees and +60 degrees in the canine and the 1 st premolar tractions. In the maxillary complex, clockwise rotation was induced by downward traction less than these angles, and the counterclockwise rotation was induced by upward traction more than these angles. 2. In the horizontal view, the degree of the curvature of the zygomatic arch tend to increase by the horizontal traction in any positions. 3. The palatine region was suggested to enlarge in the lateral direction at -20 degrees traction in any tractional positions. The enlargement gradually lessened in upward traction by the incisal traction. The palatine region between the canines was suggested to compress at +40 degrees and +60 degrees traction in the gingival hooks, and at +60 degrees traction in incisal hooks. In the canine and the 1 st premolar tractions, palatine region was suggested to enlarge in the lateral direction in any tractional directions. 4. The palatine region was suggested to compress in the backward direction in any tractional direction. The trend was not found to be different among tractional points. The maximum compression was produced in -20 degrees traction, and then gradually decreased in upward traction.

Lectin is a common name given to a certain group of hemagglutinating proteins found primarily in plant seeds, which bind specifically to the branching sugar molecules of glycoproteins and glycolipids of the surface of the cells. The author selected 3 kinds of lectin among others. Those were concanavalin A (Con A) which specifically binds to the alpha-D-mannose, wheat germ agglutinin (WGA) which binds to N-acetyl glucosamine, and peanut agglutinin (PNA) which binds to beta-D-galactosamine. The localization of these lectins was examined in order to obtain any information on the process of the proteoglycan synthesis during the cellular differentiation in the epiphyseal cartilage-plate of the rabbit. The binding sites of Con A were determined by conjugating horse radish peroxidase as a marker in case of optical microscopic observations. For the purpose of electron microscopic observations, lectins were marked with gold colloidal particles. Most Con A was found in the rough surfaced endoplasmic reticulum, while a part of them was bound to the cis side of the Golgi apparatus. In the cellular column of the cartilage, Con A was increasingly abundant from the younger proliferating stage, through the maturing stage to the stage of hypertrophy, and diminished abruptly at the stage of provisional calcification. These observations were coincided with the degree of development of the endoplasmic reticulum during the maturation of cartilage cells. These findings suggest that alpha-D-mannose is indispensable to the initial stage of proteoglycan synthesis. WGA was observed from the cis side to the intermediate layer of Golgi apparatus, but not at the trans side of the Golgi apparatus, nor in the endoplasmic reticulum. These findings suggest that N-acetyl-glucosamine is an essential substance to the middle stage of proteoglycan synthesis. PNA was found within the nucleus and at the cis side of Golgi apparatus, but not in the endoplasmic reticulum nor in the secretion granules. This observation corroborates that beta-D-galactosamine is also essential to the middle stage of proteoglycan synthesis.

Phosphofructokinase (ATP: D-fructose 6-phosphate 1-transferase) catalyzes the phosphorylation of fructose 6-phosphate (Fru-6-P) by ATP to from fructose 1,-bisphosphate, and is considered to be the key enzyme in glycolytic pathway in liver and other tissues. In dental pulp, both aerobic and anaerobic pathways of carbohydrate metabolism are present. It was reported that oxygen consumption was parallel to the activity of dentin formation, and anaerobic pathway became predominant after the cession of calcification. Analysis of glycolytic activity in bovine dental pulp revealed that PFK was also the key enzyme in this tissue. But, the regulatory mechanism of PFK in dental pulp has not been elucidated yet. In this paper, properties and regulatory mechanism of PFK in rabbit molar teeth were examined, and the following results were obtained. 1. At nearly neutral pH, PFK activity was extremely low, and it increased with the shift of pH to more alkaline side. Maximum activity was obtained over pH 8.0. 2. At physiological pH, PFK was activated with low concentration of ATP, but was inhibited with high concentration of ATP. 3. For the recovery of PFK activity from ATP-dependent inhibition, not only Fru-6-P but also AMP and fructose 2,6-bisphosphate (Fru-2,6-P2) were necessary. 4. In rabbit dental pulp, PFK was regulated synergistically by Fru-6-P, ATP, AMP and Fru-2,6-P2, and the range of the actual PFK activity seemed to be 30 to 80% of the maximum activity. 5. PFK was activated also with inorganic phosphate. But, addition of calcium resulted in the inhibition of PFK.

We performed the training for resuscitation using dental students and used a manikin for CPCR Exercise before and after the training to investigate the result obtained. The results were as follows. 1. Although cases in which too much or too little ventilation in amount was judged showed no significant changes before and after the training, those judged too much in ventilation amounted to approx. 1/5 and those judged too little were approx. 1/2 of the total subjects. This suggests that it is preferable to instruct the students to maintain sufficient ventilation when allowing them to exercise artificial breathing of CPCR. But the instruction is somewhat difficult to take because inhibition of gastric distention should be taken into account. 2. Although no changes were shown before and after the training by cases judged too deep in the depth of thoracic oppression, the number of those cases amounted to approx. 4/5 of the total subjects. Cases judged too shallow in depth of thoracic oppression, on the other hand, were significantly decreased from approx. 4/5 before training to approx. 2/3 after training, suggesting that improvement of the shallow oppression initially made is easy rather than to improve the oppression unduly deepened. Accordingly, it appears effective for students to avoid undue oppression when they are trained. 3. Thoracic oppression at a correct position was increased significantly to approx. 1/5 of the total cases, although most of the subjects were in error to choose a correct position for thoracic oppression before training.(ABSTRACT TRUNCATED AT 250 WORDS)

As an evaluation of treatment for anterior crossbite (Class I Malocclusion) in the mixed dentition, relationships were examined between the results of cluster analysis on the measured values before treatment and those on the changes caused by treatment. The following were the results of the present investigation. 1. The results of cluster analysis on the measured values before treatment were summed up into three groups; A1, A2, and A3. 1) Group A1 showing retrusion of the Maxilla and lingual version and lingual inclination of Maxillary anterior teeth. 2) Group A2 showing protrusion of the Mandible, lingual version of Maxillary anterior teeth, and lingual inclination of Mandibular anterior teeth. 3) Group A3 showing lingual version of Maxillary anterior teeth and labial version of Mandibular anterior teeth. 2. The results of cluster analysis on the changes caused by treatment were classified into three groups; V1, V2, and V3. 1) Group V1 showing labial version and labial inclination of Maxillary anterior teeth and lingual version and lingual inclination of Mandibular anterior teeth. 2) Group V2 showing protrusion of the Maxilla, labial version of Maxillary anterior teeth, and lingual version and lingual inclination of Mandibular anterior teeth. 3) Group V3 showing retrusion of the Mandible and labial version and labial inclination of Maxillary anterior teeth. 3. Relationships between Groups A1, A2, and A3 and those of V1, V2, and V3 may be summarized in the following. 1) Group A1 shows healing trend of Group V2. 2) Group A2 shows healing trend of either Group V1 or Group V3. 3) Group A3 shows healing trend of Group V1. The results shown above indicate that healing process is dependent upon many factors including a problem of mixed dentition, a problem of constructing dental arch and individual growth characteristics. Therefore, it is important for us to recognize the findings described above when treating anterior crossbite in the mixed dentition.

We postulated that high-frequency components of the occlusal sound occurring due to the characteristic vibration of teeth can be useful data for confirmation of the stability in occlusion, and studied the high-frequency components in the cases both of an experimental sliding movement and a normal occlusion. The results obtained were as follows. 1. A study on high-frequency components of the occlusal sound in an experimental sliding movement. 1) A study on wave type of the occlusal sound revealed one damped oscillation in an impact form and two in a slide form. 2) Spectrum analysis of the damped oscillation showed a similar spectrum pattern with a peak existing between 16KHz or more and 17KHz or less in both impact and slide cases. 2. A study on high-frequency components of the occlusal sound in a normal occlusion case. 1) The wave type in occlusal sound we have observed in a normal occlusion group and in a prosthetic or operative group was as follows: One damped oscillation shown in an impact form and two damped oscillation in a slide form which were the same as those shown in the case where an interference device was attached. 2) Duration of the sliding movement was short in a normal occlusion group, but was prolonged in a prosthetic or operative group. 3) The incidence of the wave type in occlusal sound was 56.7% in a prosthetic or operative group as compared to 87.8% in a normal occlusion group in an impact form. In contrast, the incidence was 43.3% in a prosthetic or operative group as compared to 12.2% in a normal occlusion group in a slide form. Such difference in the incidence between the wave types suggested that high-frequency components of occlusal sound can be an index for judgement of the stability in occlusion.

The enamel caries establishes when at least a part of enamel dissolves by the action of cariogenic bacteria which produce insoluble glucan and lactic acid. The experimental caries should be prepared at the condition which simulates the natural environment. The author made 1 mm thick sections from 29 teeth extracted for convenience of orthodontic reason. The surface was covered except the "window" which will be exposed to the acid milieu. The samples were immersed for 4 to 120 days in the gelatin added lactate buffer of pH 4.5, pH 5.0, and pH 5.5. Ground sections were made after the experiment. The structure of the experimental incipient caries was described after Darling (1963); surface layer, body of the lesion, dark zone, and translucent zone. When the section was immersed for shorter period in the buffer of pH 4.5, the lesion was made up only two layers, namely, the surface layer and the body of the lesion. This type of lesion will be called Type I, hereafter. When the action of acid was more intense, only one layer, the body of the lesion remained after the dissolution of the surface layer. This type of lesion will be called Type II. The lesion which provided with all 4 layers will be called as Type III, and the lesion which was made up of 3 layers which remained after dissolved surface layer, will be called as Type IV. Both Type III and Type IV were established after immersing for longer period in pH 5.5, although they could be observed in groups which immersed in lower pH. Of the samples examined, a few example showed a five-layered structure; the surface layer, the first body of lesion, the first dark zone, the second body of lesion, the second dark zone, and the translucent zone. This phenomenon suggests that the speed of caries development was not uniform throughout the experiment. The relationship between the depth of the lesion, and the pH and the duration of acid action was studied. In the pH 5.0 group, the development of caries lesion was temporarily arrested between 30 and 60 days. This phenomenon would be an explanation to the formation of five-layered lesion.

Effects of Exercise Tolerance on young healthy adults were studied. The results obtained were as follows. The subjects selected were non-smoking 100 volunteers aged 20 to 25 years old, without anamnesis in respiratory and circulatory systems. Exercise was conducted in an amount 3 times (test 1) or 4 times (test 2) of that in a going up and down test stipulated in the Master two step method. The results were subjected to determine changes in heart rate (HR) and ST, QT time, QT ratio and QX/QT immediately after and 5 minutes after tolerance, using ECG taken prior to the tolerance as a control. 1. Changes in each determination 1) Heart rate (HR) (HR before tolerance: 100%) Hardly any change was observed in test 1. But test 2 showed a marked increase in HR, that is 201.8% and 150.1% immediately after and 5 minutes after tolerance respectively. 2) ST change Test 2 showed ST changes of 0.4mm and 0.1mm immediately after and 5 minutes after tolerance respectively. 3) QT time and QT ratio Test 2 showed QT time of 0.29 sec. and 0.34 sec. immediately after and 5 minutes after tolerance respectively. The ratio tended to decrease as exercise tolerance increases, that is 0.92 and 0.98 in test 1 and 0.77 and 0.93 in test 2 immediately after and 5 minutes after tolerance respectively. 4) QX/QT Test 1 showed QX/QT of 0.48 and 0.49 immediately after and 5 minutes after tolerance respectively. Test 2 showed QX/QT of 0.44 and 0.47 immediately after and 5 minutes after tolerance respectively in ST change. 2. Correlation between HR and each determination HR was significantly correlated with ST changing, that is in test 2 r = -0.410 (p less than 0.01) immediately after tolerance (p less than 0.01). HR was significantly correlated with QT ratio, that is in test 1, r = -0.629, r = -0.653 and r = -0.553 control, immediately after and 5 minutes after tolerance respectively, and in test 2 r = -0.712, r = -0.708 and r = -0.785 control, immediately after and 5 minutes after tolerance respectively (p less than 0.01). 3. Correlation between HR-changing and ST-changing rate. Primary formula, that is, ST = -0.379 + 0.0174x (HR) was obtained in r = 0.672 (p less than 0.01), suggesting that ST-changing rate decreases as HR increases.(ABSTRACT TRUNCATED AT 400 WORDS)