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Biomedical subjects

O Tabata

Publications and source records attributed to O Tabata.

At least 19 recordsLinked to original sources
PubMed2005

Replica multichannel polymer chips with a network of sacrificial channels sealed by adhesive printing method.

Replica microchips for capillary array electrophoresis containing 10 separation channels (50 microm width, 50 microm depth and 100 microm pitch) and a network of sacrificial channels (100 microm width and 50 microm depth) were successfully fabricated on a poly(methyl methacrylate) (PMMA) substrate by injection molding. The strategy involved development of moving mask deep X-ray lithography to fabricate an array of channels with inclined channel sidewalls. A slight inclination of channel sidewalls, which can not be fabricated by conventional deep X-ray lithography, is highly required to ensure the release of replicated polymer chips from a mold. Moreover, the sealing of molded PMMA multichannel chips with a PMMA cover film was achieved by a novel bonding technique involving adhesive printing and a network of sacrificial channels. An adhesive printing process enables us to precisely control the thickness of an adhesive layer, and a network of sacrificial channels makes it possible to remove air bubbles and an excess adhesive, which are crucial to achieving perfect sealing of replica PMMA chips with well-defined channel and injection structures. A CCD camera equipped with an image intensifier was used to simultaneously monitor electrophoretic separations in ten micro-channels with laser-induced fluorescence detection. High-speed and high-throughput separations of a 100 bp DNA ladder and phi X174 Hae III DNA restriction fragments have been demonstrated using a 10-channel PMMA chip. The current work establishes the feasibility of mass production of PMMA multichannel chips at a cost-effective basis.

Adhesives↗
PubMed2004

A comparison and validation of amorphous sensor condylar movement analysis to MRI diagnosis of anterior disc displacement.

This study compared temporomandibular joint condylar movements in a sample of six patients with clinically normal joints, with those of nine patients with joints diagnosed by magnetic resonance imaging (MRI) to have anterior disc displacement with reduction (ADD). The aim of this study was to compare and validate the use of the amorphous sensor to MRI diagnosis in condylar movement analysis. The measuring device consisted of an amorphous sensor and a small magnet. Condylar and jaw movements were recorded simultaneously over the course of 10 open-close cycles. Maximum velocity of condylar movement during the opening phase in the ADD joints was significantly higher than the normal joints. The degree of jaw opening at the turning point of condylar movement in the ADD joints was significantly larger than the normal joints. The diagnostic sensitivity and specificity of the maximum velocity of condylar movement during the opening phase was 75.0 and 75.0%, respectively, while those of the degree of jaw opening at the turning point of condylar movement were 91.7 and 91.7%, respectively. These results suggest that the analysis of condylar movement, employing the amorphous sensor may be a reliable method for diagnosis of ADD.

Adult↗
PubMed2001

The combined use of US and MR imaging for the diagnosis of masses in the parotid region.

PURPOSE: To evaluate the usefulness of the combination of the two non-invasive modalities US and MR imaging to diagnose masses in the parotid region. MATERIAL AND METHODS: The US and MR findings of 21 patients with parotid masses were analyzed retrospectively by two radiologists without any clinical or histopathological information. The specific points evaluated were location, shape, margin, internal architecture, and intensity level on both US and MR, posterior echo enhancement on US, and capsule-like lining of the tumor on MR. RESULTS: The findings concerning the shape and margin on US and MR were in fairly good agreement. Concerning the findings of the internal architecture, US could reveal the minute structures of the tumor while MR demonstrated differences in the signal intensities of histological tissue types of the various tumors. The posterior echo enhancement on US and the capsule-like lining on MR of the tumors were also useful for the diagnosis. CONCLUSION: Our results suggest that the combination of US and MR is useful for examining soft tissue masses in the parotid region to make a more accurate diagnosis, and not just differentiate malignant lesions from those which are benign.

Adolescent↗
PubMed2000

The factors related to age awareness among middle-aged and elderly Japanese.

The purpose of this article was to expand past research by examining relationships between age awareness and related factors in Japanese middle-aged and elderly people. The subjects were 1,129 participants (575 men and 554 women, aged 40 to 79 years) of the National Institute for Longevity Sciences--Longitudinal Study of Aging (NILS-LSA). They were examined with a questionnaire and interview. As a result, chronological age, self-rated health, and visual and hearing ability tend to be the related factors for awareness of aging. Comparing the demographic and physiological factors, however, major life events, difficulties and daily life experiences showed a stronger influence on age awareness. These results provide an interesting basis for the future understanding of adult development and the meaning of aging.

Adult↗
PubMed2000

Report of three cases of Alzheimer's disease with focal motor symptoms: clinical correlates of neuroimaging findings.

We report clinical and neuroimaging findings for three patients suffering from Alzheimer's disease (AD) with focal motor symptoms. These patients initially showed cognitive deficits and subsequently featured myoclonus and awkward movements in the unilateral upper limb while progressing to paresis. Paresis was noted in the unilateral upper limb. All patients held the unilateral arm flexed at the wrist and elbow, closely adducted to the body and the hand fisted and pronated. No signs of cerebellar ataxia, sensory disturbance or long tract signs were observed, nor any of the initial non-cognitive behavioural changes typical of frontotemporal dementia. EEGs of these patients showed marked slowing of basic activity without epileptic discharges. MRIs showed progressive brain atrophy in the contralateral frontoparietal lobes as well as the hippocampal formation. Cases 2 and 3 featured extensive long T2 lesions on MRI. 99mTc-HMPAO-SPECT revealed blood flow hypoperfusion in the corresponding regions. The cerebellum and brain stem showed neither morphological abnormalities nor blood flow hypoperfusion. On the basis of these clinical and neuroimaging observations, the focal motor symptoms were attributed to contralateral frontoparietal cortical atrophy with or without white matter lesion.

Aged↗
PubMed1999

Detection of bone invasion by gingival carcinoma of the mandible: a comparison of intraoral and panoramic radiography and computed tomography.

OBJECTIVE: To assess the diagnostic accuracy of panoramic radiography (PR), panoramic radiography combined with intraoral radiography (PR+IR), and CT in detecting the supero-inferior extent of tumor invasion of the mandible by gingival carcinoma. METHOD: PR, PR+IR, and CT images of the mandible in 37 patients with gingival carcinoma were evaluated by five oral radiologists for the supero-inferior extent of bone invasion using ROC analysis. The mean ROC curve area (Az) of each observer for the different imaging modalities was analysed by nonparametric two-way ANOVA. P<0.05 was considered statistically significant. RESULTS: The mean Az for the detection of bone invasion were 0.88+/-0.03 for PR, 0.77+/-0.12 for PR+IR, and 0.87+/-0.03 for CT (P=0.0907). The mean Az for the detection of bone invasion beyond the alveolus was 0.89+/-0.07 for PR, 0.85+/-0.08 for PR+IR, and 0.83+/-0.06 for CT (P=0.5438). The mean Az for the detection of bone invasion beneath the mandibular canal were 0.94+/-0.04 for PR, 0.94+/-0.02 for PR+IR, and 0.91+/-0. 04 for CT (P=0.2466). No statistically significant differences were observed in Az between PR, PR+IR, and CT. CONCLUSION: We consider that PR+IR should be adopted as the initial imaging modality to determine the extent of supero-inferior invasion of the mandible in gingival carcinoma.

Analysis of Variance↗
PubMed1999

DNA analysis by microfabricated capillary electrophoresis device.

The LIGA (Lithographie Galvanoformung Abformung) process using synchrotron radiation lithography is applied to the microfabrication of capillary array electrophoresis (CAE) device. Laser-induced fluorescence detection system for the CAE device has been constructed by the modification of laser confocal fluorescence microscopy. DNA molecules were detected during migrating in the microchannels filled with polymer separation matrices under electric field to optimize the separation conditions for DNA analysis. Based on this observation, we demonstrated that microfabricated CAE device is realized the fast separation of DNA.

DNA↗
PubMed1998

Long-term outcomes of nonsurgical treatment in nonreducing anteriorly displaced disk of the temporomandibular joint.

OBJECTIVES: The aim of this study was to evaluate long-term outcomes of nonsurgical treatment in patients with persistent anterior disk displacement without reduction of the temporomandibular joint. STUDY DESIGN: Thirty-five patients were treated with occlusal splints, and 12 patients underwent additional occlusal treatments after splint treatment. These patients were evaluated clinically and radiographically. At least 2 years after the treatment, the 34 patients' symptoms were assessed with the use of a questionnaire. RESULTS: The mean maximal interincisal distance (MID) was 27.6 mm before treatment and 44.4 mm at the end of treatment (p < 0.001). Before the treatment, all 35 patients had complained of pain, and mild pain persisted in 9 patients at the end of treatment. Flattening of the condylar head and of the articular eminence increased in prevalence from 12.1% and 9.1%, respectively, before treatment to 54.5% and 51.5%, respectively, at the time of follow-up observation. At the time of the survey, the mean self-reported MID was 46.8 mm (p < 0.01). CONCLUSIONS: After the nonsurgical treatment, the clinical signs and symptoms improved significantly, although the prevalence of osteoarthrotic findings increased.

Adolescent↗
PubMed1998

Computed tomographic features of calcifying odontogenic cysts.

OBJECTIVES: To describe the CT appearances of 4 cases of the calcifying odontogenic cyst (COC) with particular reference to the effect of varying the window settings. METHODS: Conventional radiographs and CT scans of 4 calcifying odontogenic cysts were analyzed with respect to the presence of an impacted tooth, root resorption and calcification. In addition, increased attenuation by desquamated keratin was examined by varying the window settings on CT. RESULTS: All lesions were located in the maxilla and on conventional radiographs, had unilocular radiolucency with a well-defined margin. Calcifications and inclusion of an impacted tooth were seen in all cases. Root resorption was observed in two cases, but was not prominent. On CT, calcification was detected at the periphery of the lesion and/or around the impacted tooth in all cases. Varying the window setting revealed an increased attenuation area due to desquamated keratin. CONCLUSIONS: Varying the window setting on CT is useful as a means of identifying both desquamated keratin and peripheral calcification in COC.

Adolescent↗
PubMed1998

Electrolytes in erythrocytes of patients with depressive disorders.

The concentrations of calcium, sodium, potassium and magnesium in the erythrocytes of patients were measured in the active and remission phases of depressive disorders. Twelve patients in the active phase and 19 patients in remission with major depression were studied and compared with 20 age-matched healthy controls. Patients with major depression in both active and remission phases showed significantly lower calcium concentrations in the erythrocytes compared with controls, although no significant differences in sodium, potassium or magnesium concentrations were found among the three groups. In addition, no differences were found in the electrolyte concentrations between the active and remission phases in the same patients. This calcium concentration had no relationship to the age, gender, or medication drugs of the subjects. Low calcium concentrations were found in the erythrocytes of depressed patients, which may be a relevant marker for depression.

Adult↗
PubMed1998

Range of motion of the temporomandibular joint in rheumatoid arthritis: relationship to the severity of disease.

The purpose of this study was to determine the frequency and nature of temporomandibular joint (TMJ) involvement in rheumatoid arthritis (RA) patients with symptoms in this joint, and to investigate the relationship of symptoms to the C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and Steinbrocker stage. Clinical examination of the range of motion of the TMJ was performed in 218 RA patients. In addition, correlations between the maximal mouth opening and the severity of RA were studied. Restriction in opening the mouth (defined as < or = 30 mm movement in the central incisor region from the fully occluded to maximally open positions) was observed in 12.8% of the RA patients (28/218). The CRP, ESR and Steinbrocker stage were all correlated with maximal opening (p < 0.05). There was a positive correlation between the severity of RA and the range of motion of the jaw.

Adult↗
PubMed1997

Reliability of ultrasonography and sialography in the diagnosis of Sjögren's syndrome.

OBJECTIVE: The purpose of this study was to evaluate quantitatively observer performance with ultrasonography and sialography in the diagnosis of parotid gland involvement of Sjögren's syndrome. STUDY DESIGN: Sixty-four parotid gland sialograms and 65 ultrasonograms were prepared for observer performance experiments. They included both modalities in 24 Sjögren's syndrome and 19 nonspecific parotitis cases, 21 normal parotid gland sialograms, and 22 normal ultrasonograms in healthy volunteers. The images were randomly sequenced and presented to five observers who were asked to describe several findings and finally to determine the imaging diagnosis by ranking the abnormal features and the diagnosis on a five-point-rating scale. Observer performance was evaluated on the basis of the reliability of findings interpreted and the diagnostic accuracy of each modality from observers' rating scores. RESULTS: The diagnostic accuracy of sialography was very high, nearly perfect. The diagnostic accuracy of ultrasonography was lower than that of sialography, resulting from the lower incidence of characteristic findings in the disease groups and lower sensitivity on ultrasonography. In the differentiation of Sjögren's syndrome from the normal, however, the diagnostic accuracy of ultrasonography increased to 80% for all cases, and up to nearly 90% in the advanced sialographic stages. CONCLUSION: Ultrasonography is useful for the diagnosis of Sjögren's syndrome in the advanced stages. Taking the noninvasiveness of this technique into account we recommend first applying ultrasonography to the diagnosis of Sjögren's syndrome and performing sialography when no positive findings are detected on ultrasonography.

Analysis of Variance↗
PubMed1997

Morphologic analysis of odontogenic cysts with computed tomography.

PURPOSE: The purpose of this study was to analyze the effects of lesion site and epithelial keratinization on the morphologic characteristics of odontogenic cysts and clarify determinate factors for cyst morphology. MATERIAL AND METHODS: Computed tomographic images of 92 odontogenic cysts were analyzed: 31 primordial, 31 dentigerous and 30 radicular. Thirty-four cysts were located in the maxilla (6 primordial, 10 dentigerous, and 18 radicular) and 58 in the mandible (25 primordial, 21 dentigerous, and 12 radicular). Histologically, 31 cysts showed epithelial keratinization (18 primordial and 13 dentigerous). No keratinization was seen in radicular cysts. The morphologic features of cysts were assessed by measuring long length parallel to dental arch and short length vertical to it and calculating the long/short ratio. In addition, the computed tomography pattern of the cyst was classified into unilocular, lobulated, and multilocular patterns. Appearance of the sclerotic rim and surrounding cortex were classified into three and four patterns respectively to evaluate the developmental features of the cyst. RESULTS: As a whole, the long length of the primordial cysts was statistically larger than the other two cyst groups and resulted in a larger long/short ratio. Statistical differences of CT pattern were also seen among cyst groups. There was no preference in any cyst group for the appearance of the sclerotic rim and cortex. There were statistical differences between maxilla and mandible in short axis and long/short ratio. The maxillary cysts generally showed round shapes irrespective of their histologic characteristics. A multilocular pattern was more frequent in the keratinized group of mandibular primordial cysts. In dentigerous cysts, a multilocular pattern was seen only in the keratinized group and the long/short ratio was statistically larger; cyst shape was elliptical along the long axis. CONCLUSION: Our results demonstrated morphologic differences of odontogenic cysts caused by lesion site and keratinization. The dentigerous cyst with predominant keratinization should be included in the primordial cyst (odontogenic keratocyst) group.

Adult↗
PubMed1996

[Development of scales of relationships between grandchildren in adolescence and grandparents].

The purposes of this study are (1) to make scales of relationships between grandchildren in adolescence and grandparents, and (2) to clarify functions of grandparents perceived by grandchildren and functions of grandchildren perceived by grandparents. Subjects were 517 students in junior high schools, high schools and universities (mean of age: 17 years old), and 107 elderly persons at home (mean of age: 73 years old). As a result, factorial validity and reliability of the scales were confirmed. We found the functions of "daily emotional support", "acceptance of existence", "time perspectives", and "succession of generations" in both the grandchildren scale and the grandparents scale. Additionally we identified the function of "instrumental informational support" in the grandparents scale. The fact that the functions of "time perspectives", and "succession of generations" were found in two groups suggested the facilitation of mutual development between the generations. In addition, the function of "acceptance of existence" suggested possibilities of genuinely supportive relationships.

Adolescent↗
PubMed1993

Stafne's bone cavity. Classification based on outline and content determined by computed tomography.

Fifteen cases (16 concavities) of the so-called "Stafne's bone cavity" were investigated with the use of computed tomography. The sizes, bony outlines, and contents were analyzed on axial images. In all cases, computed tomography clearly demonstrated the concavities on the lingual surface of the mandible. There were no empty concavities. The bony outlines and contents were divided into three types. The concavities with a portion of submandibular gland as a content were larger than those with other contents. Four of six concavities not extending to the buccal cortical plate were filled solely with fat tissue, whereas all concavities with expansion of the buccal cortical plate contained submandibular gland.

Adipose Tissue↗
PubMed1993

The significance of posterior open bite after anterior repositioning splint therapy for anteriorly displaced disk of the temporomandibular joint.

Spontaneous posterior open bite was observed in 15 patients after the application of anterior repositioning splints in the treatment of anteriorly displaced disk. Recapture of the disk after treatment was clinically diagnosed in five patients. Arthrography performed on 10 patients with open bite revealed a completely recaptured disk in four patients, an anteriorly displaced disk without reduction in four patients, and an anteriorly displaced disk with reduction in two patients. This suggests that recapture of the disk in the correct position at mouth closing should be a major cause of the posterior open bite in patients who have a relatively short duration of locking and successful mandibular manipulation. Although the cause of posterior open bite with the persistently displaced disk is still unclear, an increase in the posterosuperior joint space by the posterior open bite appears to eventually produce favorable effects to joints with anteriorly displaced disks.

Adolescent↗
PubMed1993

Analysis of maxillary sinusitis using computed tomography.

Odontogenic maxillary sinusitis can be defined as sinusitis induced by a dental lesion. We examined the CT findings of 68 patients with maxillary sinusitis in order to differentiate between inflammation of sinus origin and inflammation of dental origin. Maxillary sinusitis was classified into four types according to clinical symptoms, history and conventional radiographic findings: type 1, simple sinusitis; type 2, odontogenic sinusitis; type 3, mixed sinusitis; type 4, slight sinus abnormality with a dental lesion. The relationship between the type of maxillary sinusitis and CT findings was analysed. Type 1 sinusitis exhibited severe pathological changes in both mucosa and bone which often extended into the nasal cavity and other paranasal sinuses. Type 2 sinusitis exhibited localized pathology on the unilateral antral floor. Type 3 sinusitis exhibited severe pathology characteristic of type 1 combined with type 2 sinusitis. Type 4 sinusitis could be differentiated by the CT findings into type 1 or type 2 sinusitis. The classification of sinusitis in this manner has implications for treatment planning, and CT should therefore be performed when conventional radiography does not provide sufficient information.

Female↗