Biomedical subjects

Y Okuno

Publications and source records attributed to Y Okuno.

At least 199 records · Page 11Linked to original sources

PubMed1990

Problems of denture wearers regarding denture cleaning.

With the increase of elderly population, the number of patients who need removable prostheses increase rapidly. Denture wearers have different problems from non-denture wearers in terms of maintaining oral health. In this study, we attempted to find out specific difficulties of denture wearers with questionnaires regarding social life problems as well as oral hygiene problems. Our results indicated that most of the denture wearers considered the cleaning of denture was essential to maintain their oral health, though methods they employed showed a great deal of difference. Also denture wearers felt difficulties in cleaning their dentures when they went out.

Denture Cleansers↗

PubMed1990

Mouth guard and occlusal force distribution.

Mouth guards are effective to prevent traumatic injury in maxillofacial region during sports activities. This study was designed to find out the influence of wearing mouth guards on occlusal force distribution using an occlusal force transducer system (T-Scan system). Occlusal forces were more evenly distributed when mouth guards were in place comparing with natural dentition and with wearing conventional full arch bite planes.

Adult↗

PubMed1990

[Clinical application of T-Scan System. 2. Evaluation of soft mouth guards].

Soft mouth guards are effective to prevent traumatic injury in the maxillofacial region. In this study, we tried to find out the effect of soft mouth guards on the distribution and the magnitude of occlusal force using the T-Scan system. Ten adult subjects volunteered to exert maximum biting force wearing three different types of soft mouth guards. With the limitation of the T-scan system reported in our previous article, following results were obtained. 1) Occlusal forces were more evenly distributed with soft mouth guards than without them. 2) Softer mouth guards were more effective for occlusal force distribution. 3) Since occlusal relationship between mouth guards and mandibular arch could alter the distribution pattern a great deal, occlusion of mouth guards should be examined more carefully.

Adult↗

PubMed1990

[Mouth guard and occlusal force distribution].

Mouth guards are effective to prevent traumatic injury in maxillofacial region during sports activities. This study was conducted to investigate the influence of wearing mouth guards on occlusal force distribution with the T-scan system. With comparison to the value of average occlusal force level per occlusal point (OFL) on natural dentition and wearing conventional full arch bite plane, following results were obtained. 1) Difference of OFL within the same dental arch became smaller when mouth guards were on. 2) Statistically significant difference in OFL was not found between two mouth guards with different hardness. 3) During three seconds clenching, OFL in posterior region changed great deal at the initiation but stayed at about the same level after that.

Bite Force↗

PubMed1990

[Studies on the roentgenological differentiation between complex and simple bowel obstruction].

We studied 81 cases of organic bowel obstruction. In complex obstruction 7 cases out of 25 (28%) were diagnosed on the plain film before operation, although in simple obstruction 54 cases out of 56 (96%). But in retrospective evaluation of the plain films, we noticed that in some cases of complex obstruction, marked small bowel obstruction and ascites were seen from the onset, which were never seen in simple obstruction. We considered this finding as the key point for the roentgenological differentiation between complex and simple obstruction.

Diagnosis, Differential↗

PubMed1990

[Esophageal motility and gastric emptying in PSS patients, correlation with symptoms].

Progressive systemic sclerosis (PSS) commonly involves the esophagus. Dysphagia and heartburn are the most common esophageal symptoms. In this study we evaluated the relationship between esophageal symptoms and esophago-gastric motility. On esophageal manometry, loss of peristalsis, peristaltic contraction amplitude of distal esophagus less than 30 mmHg and decreased LES pressure were critical for esophageal symptoms. The degree of symptoms correlated to esophageal dysmotility. The gastric emptying in PSS patients was delayed, but there was no significant difference in gastric emptying between the patients with and without reflux esophagitis. Esophageal dysmotility is considered to be much responsible for the reflux esophagitis in PSS patients than gastric emptying.

Adult↗

PubMed1990

[Comparative study between film mammography and xeromammography; including specimen radiography].

We retrospectively evaluated preoperative film- and xeromammography of 23 cases with breast cancers, and compared with postoperative specimen radiography to assess tumor delineation and microcalcification detectability. In tumor detection and margin delineation, film mammography was superior to xeromammography, and in microcalcification, film mammography was equal to xeromammography. These results had a effect on the diagnosis of breast cancers.

Breast Neoplasms↗

PubMed1990

[A case of cholesteatoma extending into the medial petrous bone].

A case of facial nerve palsy caused by cholesteatoma was reported. High-resolution CT was very excellent in delineating the mass extension and bony destruction. The labyrinthine segment of facial canal was thought to be the route of spread of cholesteatoma to the medial petrous bone as this case of poor pneumatized petrous bone.

Adult↗

PubMed1989

Clinical application of measurement of glucose transport in human polymorphonuclear leukocytes.

Transport of the non-metabolizable hexose analogue 3-O-methyl-D-glucose (3OMG) was measured at 37 degrees C, pH 7.4, in human polymorphonuclear leukocytes (PMNLs) obtained from 15 ml of fresh venous blood. In the study, 0.05 mM of 3OMG was equilibrated with a half-time of about 10 s, and the rate constant was 0.074/s in PMNLs from a healthy subject (male, 38 years). The coefficient of variation of values assayed on different days was about 7% and the intra-assay variation was about 2%. The transport rate did not differ between the two sexes or between subjects of different ages (23-63 years), but was significantly higher in 23 patients with non-insulin-dependent diabetes than in 29 normal controls (13.3 +/- 3.7 vs. 10.4 +/- 2.5 fl/cell.s, mean +/- SD). In conclusion, the measurement of transport of 3OMG in PMNLs may be useful for the study of glucose transport in clinical investigations.

3-O-Methylglucose↗

PubMed1989

Incidence of subacute sclerosing panencephalitis following measles and measles vaccination in Japan.

The Japanese Committee for the National Registry of Subacute Sclerosing Panencephalitis (SSPE) confirmed that 215 cases of SSPE occurred in the 20 years from 1966 to 1985, as discovered in the 10-year surveillance from April 1976 through March 1986. The annual incidence in recent years has been between 10 and 23 cases. Among cases with a certain history of measles illness or measles vaccination, 184 (90.2%) had a history of measles illness without receiving measles vaccine. There were 11 probable measles vaccine-associated cases (5.4%), three (1.5%) being vaccinated with a combined use of killed and live vaccine and eight (3.9%) with further attenuated live vaccine. There were nine cases (4.4%) without a history of either measles illness or measles vaccination. Intervals between measles illness and the onset of SSPE varied from 1 to 16 years (mean, 7.0 years). The periods following measles vaccination with further attenuated live vaccine were 2 to 11 years (mean, 4.6 years). Annual incidence rates of SSPE per million cases of measles ranged between 6.1 and 40.9 (mean, 16.1) in the 10 measles epidemic years 1968-1977, and those following vaccination with further attenuated live vaccine were zero in most years and at the highest 3.08 (mean, 0.9) per million doses of distributed vaccine.

Adolescent↗

PubMed1989

Detection of dengue 4 virus core protein in the nucleus. I. A monoclonal antibody to dengue 4 virus reacts with the antigen in the nucleus and cytoplasm.

A mouse monoclonal antibody (MAb) to dengue 4 (DEN-4) virus reacted with the antigen in the nucleus as well as in the cytoplasm of DEN-4-infected mammalian and mosquito cells, as demonstrated by the peroxidase-antiperoxidase staining method. The intranuclear antigen appeared to accumulate at the nucleoli, forming spots, whereas the cytoplasmic antigen appeared to be localized mainly in large perinuclear foci in the infected cells. The MAb-reactive antigen was produced in the presence of actinomycin D, which caused the accumulation in the nucleus to be altered to a dispersed pattern. Radioimmunoprecipitation analysis of [35S]methionine-labelled purified virions and Western blot analysis of the antigens prepared from the infected mammalian and mosquito cells showed that the MAb was directed against the DEN-4 virus core protein (Mr 15.5K). These results indicated that the DEN-4 virus core protein was partially transported, soon after its synthesis in the cytoplasm, into the nucleus and accumulated at the nucleoli.

Aedes↗

PubMed1989

A case of dengue hemorrhagic fever in a Japanese child.

A 6-year-old Japanese girl contracted a febrile illness with hemorrhagic manifestations when she traveled in Indonesia. A remarkable decrease in the numbers of platelets and white blood cells was observed in her acute-phase blood specimens. Her father, who accompanied her, showed dengue fever-like symptoms at almost the same time as her illness. It was determined by serological tests that they were infected with dengue virus type 1. Moreover, she showed a secondary antibody response to the flavivirus due to the pre-existing antibody to Japanese encephalitis virus. This is the first confirmed case of dengue hemorrhagic fever (DHF) in Japanese people.

Child↗

PubMed1989

[Percutaneous recording of gastric electrical activity (electrogastrography): its technique and analysis].

In 1922, Alvarez made some electrical recordings from cutaneous electrodes, but the method has not been widely adopted. It has been caused by the technical difficulties in recording, and in extracting consistent information from the recording. Therefore in an effort to improve the ability to routinely obtain a recording of the gastric electrical activity, using cutaneous electrodes (electrogastrography, EGG), we have investigated different electrodes placement and bipolar recording techniques. We studied 10 healthy asymptomatic volunteers. Frequency and power product have been used to help interpret the potential change. We found significant frequency component at approximately 3 cycle/min. Recordings from the upper part of epigastrium were better than those from the lower part of epigastrium. This suggests that these recordings are taken from electrical activity of the stomach. We found the good placement of cutaneous electrodes and good recording techniques.

Action Potentials↗

PubMed1989

[Effect of bite plane on electromyographic activity of masticatory muscles. 1. Muscle activity during tapping movement].

The purpose of this study is to examine the influence of the insertion of bite plane on masticatory muscle activity during tapping movement, and find out useful parameters for examination and diagnosis of stomatognathic dysfunction. The subjects in this study were twenty normal subjects with intact dentition and no signs of mandibular dysfunction as the control group, and twelve subjects with unilateral temporomandibular joint pain during jaw opening or closing movement as the patient group. Electromyographic activity in the bilateral anterior temporal and masseter muscles and mandibular movement using the Mandibular Kinesiograph were recorded simultaneously during tapping movement. The usefulness of the 61 items used in this study was evaluated. The results were summarized as follows: 1. In the patient group, a significant correlation between the jaw opening degree during tapping movement and the maximal jaw opening one without pain was recognized. 2. The total muscle activity in the patient group decreased significantly by the insertion of the bite plane. 3. Many subjects of the patient group showed a significant difference between the right and left activity of each muscle. 4. A significant difference between the two groups was found in the duration of muscle activity before and after Silent period, those coefficients of variation and the difference between those durations of the right and left muscle activity. This study suggests that the above factors are very useful parameters for examination and diagnosis of temporomandibular joint dysfunction.

Humans↗

PubMed1989

[Simulation of bone resorption in denture patients using finite element analysis. 1. Application of optimization method].

The purpose of this study was to simulate the process of bone resorption under removable denture bases. Two dimensional finite element models were prepared for the frontal section of a maxillary complete denture with its supporting mucosa and bone in the first molar region. Simulations were performed with the optimization program which could proportionally move the nodal points according to the stress level difference between the actual and the reference stress level. By exerting loads on occlusal table of the model, the bone resorption progressed in the similar manner to reported clinical observations. The location and magnitude of the resorption were highly related to the location and direction of the loads.

Alveolar Bone Loss↗

PubMed1989

Cutaneous branches from the dorsal rami of the cervical nerves, with emphasis on their positional relations to the semispinalis cervicis.

The courses of the cutaneous branches arising from the dorsal rami of the cervical and the upper thoracic nerves were examined on 61 sides in 31 human adults, and their positional relations to the semispinalis cervicis muscle were particularly noted. Absence of the cutaneous branch from the dorsal rami of the lower cervical nerves was observed in 60 of the 61 cases; and in the one remaining case, all the cervical nerves except C1 gave off a cutaneous branch. A difference in course of the cutaneous branches was clearly observed between those from the upper cervical and the upper thoracic segments. That is, those of the former passed superficial to the semispinalis cervicis, whereas those of the latter were situated deep to it. The absence of cutaneous branches of the lower cervical segments could be classified into two types: continuous absence and alternate absence. In the former, which was observed in 53 cases (87%), cutaneous branches were absent in continuous segments. In the latter, which was observed in 7 cases (11%), they were absent in alternate segments. Dermatome problems are discussed on the basis of the present results. Keegan-Garrett's chart could be supported in the one exceptional case only.

Cervical Plexus↗

PubMed1989

[Inference engines of expert systems for designing removable partial dentures].

The expert system for designing removable partial dentures has a great potentiality for clinical and educational use. The system sorts out several solutions for clinical problems with the aid of logic and data bases stored in the memory bank. The most important part of this system is the inference engine. Production system and frame system are often used as the inference engine. The purpose of this report was to compare different types of inference engine in practical situations. Following conclusion were obtained. 1) Since each type of inference engine has its own advantages and disadvantages, one has to select most suitable one for the purpose of the system. 2) One must select the inference engine type which will help potential user's understanding.

Denture Design↗

PubMed1989

[Clinical application of T-scan System. 1. Sensitivity and reproducibility and its application].

Analyzing occlusal contacts is significant for establishing the occlusal scheme as well as for the diagnosis on dysfunction of stomatognathic system. We tested a new occlusal contact analyzing device (T-Scan: Tekscan Inc. Boston, U.S.A.) for its sensitivity and reproducibility in relation to its clinical application. Following results were obtained. 1) As the modeling of dental arch of this system was not always correct, much care should be needed for identifying the contact location. 2) The minimum amount of load needed for displaying each five step occlusal force increased linear fashion (step 1: 250 g and step 5: 1750 g) when the sensor was vertically pressed on the intersection of force sensitive line. The minimum amount of force changed with the loading condition such as area and direction. Distortion of the sensor could lead the measurement error. 3) Since the time measurement data by this system were shorter than actual length of time and were measured over about 250 g load, light and early occlusal contacts could not be detected.

Dental Arch↗