Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

At least 73 records · Page 4Linked to original sources

PubMed2003

Magnetic resonance imaging analysis on the relationship between anterior disc displacement and balancing-side occlusal contact.

The purpose of this study was to evaluate the relationship between balancing-side occlusal contact patterns and the prevalence of the internal derangement of the temporomandibular joint (TMJ). Forty-one patients were used for the magnetic resonance image (MRI) analysis of TMJ and occlusal examination. Balancing-side occlusal contact patterns observed during mandibular lateral excursive movements were classified into the three following categories: group A, simultaneous balancing-side contact, group B, balancing-side contact (with clenching only) and Group C, no balancing-side contact (with or without clenching). By the occlusal examination of 57 sides, 31.6% showed group A, 8.8% showed group B and 59.6% showed group C contact. Group A could not be observed in the patient group with normal disc position. In the disc displacement group, the prevalence of group A, group B and group C were 40.9, 6.8 and 52.3%, respectively. The higher prevalence of simultaneous balancing-side contact was revealed to be associated with articular disc dislocation.

Adolescent↗

PubMed2003

Visual observation of the dynamic flow of elastomer rubber impression material between the impression tray and oral mucosa while seating the impression tray.

The purpose of this study was to inspect visually, the dynamics of the impression flow at seating of the impression tray. The effects of the relief and the escape hole of the impression tray on the impression flow were also examined. Three types of the transparent impression tray (flat tray, relief tray and escape hole tray) were prepared. Transparent silicone polymer was put on the impression tray surface. Four drops of the dark blue silicone impression material was injected into the transparent silicone polymer on the impression tray. The impression tray was seated on the model of the denture-supporting mucosa. The movement of the four drops caused by the impression flow was visually recorded with the video camera and examined. The result for the flat tray showed that the impression material moved from inside to the outside. It was also shown that the speed of the moved impression material increased as the seating of the impression tray advanced. The results for the relief tray and the escape hole tray showed the effect of the relief and the escape hole prepared to the impression tray on the speed and the direction of the flow of the impression material.

Dental Impression Materials↗

PubMed2003

Finite element analysis of the effect of the bucco-lingual position of artificial posterior teeth under occlusal force on the denture supporting bone of the edentulous patient.

To improve the quality of the complete denture prosthesis, the bucco-lingual position of the artificial posterior teeth must be determined with consideration of the shape of the maxillary and mandibular residual ridge and the relationship between them. The arrangement of posterior artificial teeth should be considered not only for the denture stability but also for the avoidance of high pressure on the supporting structures. A two-dimensional finite element method program to investigate the statics for the contour of the complete denture and the residual ridge was developed. With this program, the effect of the bucco-lingual position of the artificial posterior teeth under occlusal force on the denture supporting bone could be investigated.

Bite Force↗

PubMed2003

Galvanic skin response of oral cancer patients during speech.

Severe speech difficulty is often caused after surgery of an oral cancer. Prosthetic treatment with a removable obturator prosthesis is generally provided for such patients. Although some speech ability is recovered with prosthetic treatment, patients sometimes complain of continued dissatisfaction with their speech. However, it is difficult to evaluate the dissatisfaction. Therefore, a new method for evaluation is desirable. In this study, such a new method using the galvanic skin response as the index for the dissatisfaction of the patient was developed, and its objectivity was investigated. Eleven patients with maxillary bone defects were selected. Prior to the evaluation, improvement of speech with the removable prosthesis was confirmed using the speech intelligibility test and the visual analogue scale. The electrical resistant value at pronunciation was measured with the measuring system composed with the apparatus (galvanic skin response (GSR) measuring apparatus), the personal computer program. The changes for the electrical resistant value after pronunciation were evaluated by calculating the decrease ratio at pronunciation [(the mean electrical resistance before pronunciation - the mean electrical resistance after pronunciation)/the mean electrical resistance before pronunciation]. This decrease ratio at pronunciation was defined as the index of the speech dissatisfaction of the subject. The mean values for the decrease ratio with prosthesis were significantly smaller than the values without prosthesis (P < 0.05). From the results of this study, it is suggested that the measurement of the electrical resistance change of the skin during speech could be a new method for evaluating the speech dissatisfaction of the post-oral-cancer patient.

Female↗

PubMed2003

Plasma treatment increased shear bond strength between heat cured acrylic resin and self-curing acrylic resin.

Self-curing acrylic resin is generally used for the repair of a fractured denture base. However, re-fracture of the repaired denture base resin often occurs because of poor bonding strength between the base resin and self-curing repair resin. The effect of plasma treatment on the shear bond strength between heat cured acrylic resin and the self-cured acrylic was examined. It was revealed that plasma irradiation is effective in increasing the shear bond strength. Plasma irradiation does not cause environmental pollution, as it does not require chemicals. It is a useful method to increase adhesive strength between heat cured acrylic resin and self-curing acrylic resin.

Acrylic Resins↗

PubMed2003

Taenia solium taeniasis/cysticercosis in Papua, Indonesia in 2001: detection of human worm carriers.

A preliminary study to detect human worm carriers of Taenia solium in Papua (Irian Jaya), Indonesia was carried out using stool examinations for the detection of copro-antigens and adult proglottids after chemotherapy, and confirmation by mitochondrial DNA analysis using expelled proglottids and metacestodes developed in NOD/Shi-scid mice from eggs of expelled proglottids. Approximately 8.6% of the local population in Kama (5/58), 1 km from the local capital city centre, Wamena, were confirmed to harbour adult T. solium using these techniques.

Adolescent↗

PubMed2003

A proton-pump inhibitor, rabeprazole, improves ventilatory function in patients with asthma associated with gastroesophageal reflux.

BACKGROUND: Treatment of gastroesophageal reflux (GER) with proton-pump inhibitors (PPI) improves symptoms of asthma in some patients. However, the effects of a PPI on ventilatory function are still controversial. In this study, we measured ventilatory function in asthma patients treated with a PPI in order to identify those in whom a therapeutic effect on asthma can be expected from the acid suppression. METHODS: From a cohort of 114 consecutive patients with bronchial asthma, 53 patients agreed to participate in the study and were treated with rabeprazole 20mg daily for 8 weeks during an asymptomatic, stable period with no exacerbations of their asthma. Of the 53 patients, 22 were diagnosed as GER on the basis of the QUEST questionnaire and endoscopic examination. The patients were monitored for improvement in ventilatory function. RESULTS: Four patients dropped out because of adverse drug reactions. All the patients with GER noted an improvement in reflux symptoms with PPI treatment. An improvement of more than 20% in peak expiratory flow (PEF) was observed in 8 of 21 GER patients but in none of the non-GER patients. Factors predictive of improvement in PEF with rabeprazole therapy were the QUEST score (odds ratio: 1.47, 95% CI: 1.06-2.04, P = 0.022) and steroid-dependency of asthma (odds ratio: 0.01, 95% CI: 0.001-0.31, P = 0.008). CONCLUSIONS: Treatment with rabeprazole is expected to ameliorate asthma in non-steroid-dependent patients who have symptomatic GER defined by the QUEST score.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2003

Decreased computed tomographic lung density during exacerbation of asthma.

Recently, it was shown that both mean lung density (MLD) and the relative lung area with an attenuation of <-950 HU (RA950) are related to severity of asthma in nonsmoking asthmatics. The aim of the present study was to examine whether reduced computed tomography (CT) lung density during exacerbation could change after treatment. A cross-sectional study was performed to compare CT lung density in 30 stable asthmatics, 30 unstable asthmatics and 25 control subjects. In order to investigate longitudinally the effect of treatment on decreased CT lung density, 17 asthmatics with an exacerbation were followed at the initiation of treatment and 2 months after relief. The MLD was significantly lower and the RA950 significantly higher in unstable asthmatics than in controls and stable asthmatics. Both MLD and RA950 changed significantly with administration of systemic glucocorticoid therapy. The changes in forced expiratory volume in one second correlated significantly with those in both MLD and RA950. The changes in residual volume also correlated significantly with those in both MLD and RA950. It was concluded that decreased computed tomographic lung density during an asthma exacerbation is at least partially reversible, and changes in mean lung density and the relative lung area with a radiation attenuation of <-950 HU are related to the change in forced expiratory volume in one second and residual volume.

Adult↗

PubMed2003

Invasive ductal carcinoma of the mammary gland in a mare.

A 21-year-old thoroughbred mare had a 35 x 14 x 10 cm mass involving the mammary gland. Metastases were found in the kidneys, lungs, skeletal muscles, and regional lymph nodes. Histopathologic examination of the tumor revealed a ductal solid carcinoma with extensive intraductal and intralobular involvement and focal infiltration of the adjacent stroma. The intralobular neoplasms were divided into irregularly shaped islands and sheets of polygonal and spindle-shaped epithelial cells by thick or thin fibrous connective tissue bundles. The neoplastic cells had a small or moderate amount of cytoplasm that stained faintly with eosin and round or oval hyperchromatic nuclei. Immunohistochemically, the neoplastic cells were strongly positive for Lu-5, weakly positive for AE1/AE3, vimentin, and glial fibrillary acidic protein, and negative for cytokeratin 8, cytokeratin 14, alpha-smooth muscle actin, calponin, and S100. The neoplasm was diagnosed as an invasive ductal carcinoma of the mammary gland with multiple metastases.

Animals↗

PubMed2003

Immunohistochemical evaluation of a malignant intestinal carcinoid in a dog.

An intestinal carcinoid with multiple metastases was identified in a 5-year-old male Shih Tzu with a clinical history of anemia, fatigue, anorexia, vomiting, intermittent diarrhea, intestinal bleeding, and progressive emaciation. There was a yellowish-white mass 15 mm in diameter in the anterior jejunum and white nodules consistent with metastases in many organs. Histopathologically, the mass consisted of neoplastic cells arranged in lobules, trabeculae, or closely interdigitating islands of cells. Neoplastic cells were generally polygonal with round hyperchromatic nuclei, modest amounts of eosinophilic cytoplasm, and eosinophilic cytoplasmic granules. Mitoses were common. Rosette formations of tumor cells were apparent in metastatic tumors. Immunohistochemically, tumor cells stained positive for cytokeratin 13, synaptophysin, protein gene product 9.5, neuron-specific enolase, chromogranin A, calcitonin gene-related peptide, serotonin (5-HT), and Leu-7. Serum 5-HT concentrations for this dog were increased 10-fold compared with those of normal dogs. All findings were consistent with a diagnosis of a malignant intestinal carcinoid.

Animals↗

PubMed2003

Experimental transmission of abnormal prion protein (PrPsc) in the small intestinal epithelial cells of neonatal mice.

Using an immunohistochemical method, we attempted to detect the transmission of abnormal prion protein (PrPsc) to the enterocytes of the small intestine of neonatal mice by oral exposure with sheep brain affected by scrapie. Five 1-day-old neonatal mice were exposed by oral inoculation to the homogenized brain of a scrapie-affected sheep. In the small intestine of all mice 1 hour after inoculation, immunoreactivity with antinormal prion protein (PrPc) antibody was seen in the cytoplasm of villus enterocytes. This finding suggests transmission of abnormal PrPsc into the cytoplasm of enterocytes. In control mice treated with normal sheep brain, no PrPc signal was seen in enterocytes of the small intestine. Immunopositivity for neurofilament protein and glial fibrillary acidic protein was seen in the cytoplasm of enterocytes of mice inoculated with scrapie and normal sheep brain. This suggests that the enterocytes of neonatal mice can absorb PrPsc and other macromolecular proteins of the sheep brain affected by scrapie and may be more important than previously thought as a pathway for PrPsc transmission in neonatal animals.

Animals↗

PubMed2003

[Emergency pleuropneumonectomy via anterior approach to treat chronic hemorrhagic empyema due to massive hemoptysis].

A 67-year-old man with a history of surgical resection of the superior lobe of the left lung and thoracoplasty due to pulmonary tuberculosis occurring approximately 40 years previously, was admitted to the hospital due to recurrent hemoptysis. X-ray films and computed tomography (CT) scans of the chest showed the left thoracic cavity to be filled with empyema, compressing the inferior lobe downward. Since three unsuccessful attempts were made at bronchial artery embolization for hemostasis, yielding hemoptysis of approximately 1,000 ml, emergency surgery was performed. To prevent massive intra-operative hemoptysis, the left pulmonary artery was blocked by median sternotomy. A transverse incision was then made, and thus pleuropneumonectomy could be safely performed. Since it allows early blocking of blood vessels surrounding the hilum of the lung and the main bronchus, anterior approach is useful in treating hemorrhagic empyema and wet pleurisy with internal fistula.

Aged↗

PubMed2002

Characterization of the portal signal in a nonsteady hyperglycemic state in conscious dogs.

To characterize the "portal signal" in a nonsteady hyperglycemic state, the kinetic relationship between net hepatic glucose balance (NHGB) and either hepatic glucose load (HGL) or plasma insulin level was determined during glucose infusion using a catheter technique in 36 conscious dogs. Glucose was infused intraportally (Po group) and peripherally (Pe group) at 39, 56, and 83 micromol x kg(-1) x min(-1) over 2 h. There was a linear relationship between mean NHGB and either mean HGL or plasma insulin levels at each rate in either delivery (HGL: Po r = 0.99, Pe r = 0.95; insulin: Po r = 99, Pe r = 0.79). The threshold levels for net hepatic glucose uptake were 3.8 and 11.7 mmol/l for plasma glucose and 65 and 392 pmol/l for plasma insulin, respectively. The slope of the regression line against the abscissa was four times larger in portal than in peripheral delivery (HGL: Po 0.20 vs. Pe 0.05, P < 0.05; insulin: Po 0.19 vs. Pe 0.04, P < 0.05). These results suggest that the portal signal overrules the threshold of glucose for hepatic uptake by increasing hepatic extraction rate in a nonsteady hyperglycemic state.

Animals↗

PubMed2002