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T Amagasa

Publications and source records attributed to T Amagasa.

At least 73 records · Page 4Linked to original sources

[Electronmicroscopic study on tongue squamous cell carcinoma--radiotherapy cases].

We examined the ultrastructures of the tongue squamous cell carcinomas which received radiotherapy and compared the metastatic cases with the non-metastatic cases. The results were as follows: 1. The non-metastatic cases were clinically T1N0 or T2N0 and histologically Grade I or II of the WHO classification. Electronmicroscopic observation of these cases revealed that numerous microvilli and a small number of desmosomes were found and the cell attachment seemed to be weak. These findings were different from those of the non-metastatic cases which received surgery. 2. In the metastatic cases of which the primary lesions were controlled, microvilli were not developed and a number of desmosomes were shown as compared with those in the non-metastatic cases. However, cell atypia and dispersion of the nuclear chromatin were clearly recognized.

Adult↗

Identification and characterization of autocrine-motility-factor-like activity in oral squamous-cell-carcinoma cells.

A human oral squamous-cell-carcinoma cell line, HOC313, was found to produce a factor which stimulates cell motility in an autocrine manner. The motility factor of HOC313 cells also promoted the locomotory activity of B16 murine melanoma cells reported to be sensitive to autocrine motility factor (AMF). HOC313 cells were found to express a large amount of AMF-receptor mRNA. In addition, the cell motility activity of HOC313 cells was completely blocked by pertussis toxin, a known inhibitor of AMF activity, suggesting that the motility factor of HOC313 cells may be AMF or a closely related factor. Immunocytochemical analysis has revealed that the AMF-like factor of HOC313 cells diminishes the cell-surface expression of adhesive molecule E-cadherin. These results suggest that down-regulation of E-cadherin may be involved in the cell-motility activity induced by the AMF-like factor of HOC313 cells.

Animals↗

Molecular cloning of rat bone morphogenetic protein (BMP) type IA receptor and its expression during ectopic bone formation induced by BMP.

A cDNA for the rat bone morphogenetic protein (BMP) type IA receptor (BMPR-IA) was isolated from a dental pulp cell cDNA library. The rat BMPR-IA cDNA encodes a protein of 532 amino acids with a single transmembrane domain and a putative serine/threonine kinase domain. The overall amino acid sequence identity between the rat and human BMPR-IA was 97%. Reverse transcriptase-polymerase chain reaction analysis revealed that BMPR-IA mRNA was highly expressed in the BMP-induced bone forming tissues throughout the stages tested.

Amino Acid Sequence↗

Oral malignant melanoma in Japan.

Clinical examination was performed on 20 cases of malignant melanoma in the oral region encountered at the First Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Tokyo Medical and Dental University, during the 22-year period from 1970 to 1991. In addition, we reviewed 140 cases reported in the Japanese literature since the last major review in 1974. The results of our study revealed that the clinical course of malignant melanoma in the oral region is worse than oral squamous cell carcinoma and that treatment by radiotherapy is effective in prolonging the life of these patients. Clinically, the tumors were classified into five types: (1) pigmented nodular type; (2) nonpigmented nodular type; (3) pigmented macular type; (4) pigmented mixed type; and (5) nonpigmented mixed type. We suggest that oral malignant melanoma might be different from cutaneous malignant melanoma and that new criteria for diagnosis and therapy for oral disease should be considered.

Adult↗

Basic properties of super-elastic Ni-Ti alloy ligature wires for a new intermaxillary fixation method.

A new continuous wiring method of intermaxillary fixation with super-elastic Ni-Ti alloy ligature wires was developed to avoid the risk in postoperative emergency. Differential scanning calorimetry, three-point bending tests and fastening tests were carried out to investigate basic properties of the wires. Transformation temperatures of the Ni-Ti alloy wires were in the range suitable for exhibiting super-elasticity at body temperature. The Ni-Ti alloy wires possessed enough bending flexibility to be used in the continuous wiring method and showed great recoverable displacement in the fastening test. With use of these properties, easy removal in an emergency and uniform fixation can be attained.

Alloys↗

Aetiology of maxillofacial fracture.

The aetiological factors associated with maxillofacial fractures, and the trends in these factors over a 13 year period are reported. The First Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Tokyo Medical and Dental University, managed 695 patients with maxillofacial fractures between 1977 and 1989. The male to female ratio was 3.2:1 and the majority of patients were aged between 10 and 30 years old. Road traffic accidents and accidental falls were the main causes of fractures throughout the 13 year study period. Mandibular fractures occurred in 477 patients (68.6%). A high percentage of patients were treated by closed reduction and maxillo-mandibular fixation, or occlusal splinting.

Accidental Falls↗

Transferrin receptor in oral tumors.

The transferrin receptor (TfR) appears in vigorously proliferating cells. We did an immunohistochemical study of TfR in oral tissues and a quantitative analysis by flow cytometry of TfR in a cancer cell line after an anticancer drug treatment. TfR was found in the parabasal and basal layers of the normal epithelium, but rarely in benign tumors. Generally, in the malignant tumors, the poor prognostic cases showed strong staining regardless of the differentiation of the tumor. In the flow cytometric analysis, the amount of TfR decreased according to the reduction of the proliferative ability of cancer cells. These results suggest that TfR expression may be useful as a prognostic marker.

Adult↗

Oral and maxillofacial reconstruction using the free rectus abdominis myocutaneous flap. Various modifications for reconstruction sites.

The rectus abdominis myocutaneous flap consists of the skin paddle, anterior rectus sheath, rectus muscle and deep inferior epigastric artery and veins. Of these four components, the skin paddle, rectus sheath and rectus muscle could all be adjusted appropriately for reconstruction sites. Only one or two large perforators in the paraumbilical region could easily supply the large abdominal wall. The bulkiness of the rectus abdominis flap is reduced by removal of subcutaneous fat and rectus muscle. These possibilities can provide many modification of the flap for various reconstruction sites. 16 cases were reconstructed primarily and secondarily using this flap after oral and maxillofacial tumour ablation. The results of these cases indicated a very favourable and reliable vascularity. The rectus abdominis myocutaneous flap was considered to be one of the most suitable flaps for oral and maxillofacial reconstruction. Various modifications for different reconstruction sites are mainly discussed.

Adipose Tissue↗

Effects of insulin on in vitro bone formation in fetal rat parietal bone.

We examined the effects of insulin on bone formation including the mineralizing process. Twenty-day fetal rat parietal bones were cultured for 96 h on grids in a serum-free medium. For the precise assessment of bone formation, histomorphometry, with an image analyzing system, was used to measure the areas of mineralized bone and bone matrix, and the numbers of osteoblasts and osteoclasts. In order to confirm the effects of insulin on bone mineralization, the calcium content of the bone and the release of previously incorporated 45Ca into the medium were measured. Insulin, at a concentration of 10(-6) M or higher, increased the areas of mineralized bone and bone matrix, and the number of osteoblasts. Osteoclasts were seldom observed in bones on day 0 or in bones treated with insulin. In bones treated with insulin at a concentration of 10(-6) M, the calcium content of bone increased. At an insulin concentration of 10(-7) M or higher, the dry weight of decalcified bone increased. Lactate production in the medium increased dose-dependently. The inhibited release of 45Ca in bones indicated that insulin acts by increasing calcium retention. We demonstrated that insulin has an effect on bone-forming and bone-resorbing cells to enhance the bone forming process from matrix formation to mineralization.

Animals↗

Squamous cell carcinoma of the maxillary sinus and the oral part of the upper jaw. Comparison of treatment results.

The treatment results were compared in 77 patients with maxillary sinus squamous cell carcinoma (MC) and 53 patients with squamous cell carcinoma arising from the oral part of the upper jaw (OC). Both sets of patients received radiotherapy alone, or radiotherapy combined with surgery and/or chemotherapy. Computerized tomography was useful for the definition of the treatment volume. Intraarterial chemotherapy was given in 89 of 130 patients and in these patients the total radiation dose was reduced by about 10 Gy. No difference was found in the 5-year survival rate between the MC (65%) and the OC (66%) groups. The cumulative incidence of local failure was higher in MC (36%) than in OC (26%), whereas the ultimate incidence of neck node metastasis was higher in OC (43%) than in MC patients (18%). Half of the inoperable patients (9/18) were older than 80 years and had contraindications to anaesthesia and major surgery. The local recurrence rate was high in the inoperable MC patients (6/8). Contralateral sinus cancers occurred in 4 patients in the MC group.

Aged↗

[Assessment of social disability of patients suffering from chronic mental illness with the role play test].

UNLABELLED: Among the chronic mentally ill patients, disabilities invade most parts of their social functioning, and influences their long term course profoundly. It is important clinical issue to improve disability. Social skills training is assumed to be effective method to improve disability, and it has been disseminated over Japan recently. The assessment system to evaluate disabilities objectively at the viewpoint of social skills must be required to verify effects of social skills training, and to develop further effective therapeutic method. A role play test is the assessment tool for social skills through role plays under specific social conditions. It was reported to be useful as the method of functional assessment before treatment, and as the tool to evaluate effects of treatment to improve disability. PURPOSE: We created the Role Play Test (RPT) which was adapted to Japanese cultural background, and we tried to verify feasibility, reliability, and validity of the RPT. SUBJECTS: Thirty out-patients attending in the Day Hospital attached to Tokyo University Hospital. Twenty-six were schizophrenia, and 4 were other diagnoses. METHOD: Subjects were assessed with the RPT, BPRS, SANS, four rating scales for social functioning, and self-efficacy rating scale. The RPT was designed to assess components of social skills--social perception, role play behavior, and self-efficacy. Role play behaviors were recorded with video tapes for analysis of interrater reliability. The RPT is consisted of 12 scenes to evaluate social skills which are required in daily life. Statistical analyses were done with SAS (Statistical Analysis System). RESULTS: (1) The RPT was presumed to be feasible clinically, because the RPT could be practiced easily and responsibilities of both subjects and testers were not so much. (2) Interrater reliabilities assessed with ANOVA-ICC on 12 items was sufficiently high except one item. (3) Construct validity was certified through factor analysis, and criterion-related validity was certified through correlation analysis with other rating scales of social functioning. (4) Individual profile of the RPT should be useful instrument for functional analysis before social skills training. We also discussed on some hypotheses on the causal relationship between positive and negative symptoms and social skills. The RPT could be used as a tool to research causes of disabilities, and to evaluate improvement of social functioning after psycho-social intervention including social skills training, because the RPT can assess social skills quantitatively according to the cognitive-behavioral model.

Adolescent↗

Reconsideration of the bilaminar zone in the retrodiskal area of the temporomandibular joint.

The fibrous connection of the diskal attachment to the condyle and to the surrounding structures, and of the retrodiskal area was investigated histologically. Sections, obtained from six temporomandibular joints with the condyle protruded, were mainly observed. Most of the collagen fibers that compose the posterior band were attached to the condylar poles and to those vicinities behind them, and no diskal attachment was found to the posterior aspect of the condyle. Elastin-rich fibers that originate from the petrotympanic fissure were attached to the disk at the medial end. These fibers had many branches that compose a part of the retrodiskal area and were very wavy in spite of the protruded position of the disk-condyle complex. No other fibers directly connected the disk with the posterior wall of the fossa. Therefore we concluded that there were no upper and the lower strata as termed by Rees.

Adult↗

Maxillofacial fractures in children.

A clinico-statistical and long-term follow-up study was performed on 81 pediatric fractures seen during the 14 years between 1977 and 1990. Of all maxillofacial fractures, the incidence of pediatric fractures was 14.7%. The ratio of boys to girls was 2.1:1, and the highest incidence involved boys over 13 years of age. Fractures of the upper alveolar bone and mandible were common. Conservative therapy, such as maxillomandibular fixation using orthodontic brackets was usually performed and was found to be successful. The long-term follow-up study revealed that 5 out of 21 patients with alveolar fractures complained of malocclusion and it is suggested that a longer duration of intramaxillary fixation and long-term follow-up might be needed for alveolar fractures in children.

Adolescent↗

Computed tomography and ultrasonography in submandibular tumours.

The value of computed tomography (CT) and ultrasound (US) for assessing submandibular tumours has been assessed. Thirty-five patients with 23 benign submandibular gland tumours and 12 malignant tumours have been investigated. In 33/35 patients, 18 plain CT (PCT), 19 CT sialography (CTS), and eight intravenous contrast-enhanced CT (CECT) procedures were performed. PCT did not allow clear delineation of 78% of the lesions, due to the similar density of the tumour and normal submandibular gland parenchyma. The tumours were easily recognized as low-echogenic or low-density masses by US, CTS and CECT. Benign lesions were usually sharply demarcated and had smooth borders on US, CTS and CECT. In addition, lobulation was often recognized in pleomorphic adenomas. Malignant tumours were poorly defined with irregular borders in 11/12 cases on US, CTS and CECT. CECT was superior to PCT and CTS in providing images of the tumour and its involvement of adjacent structures. It was concluded that US is the most useful primary examination method for submandibular tumours, while CECT provides the best evaluation of extension to the surrounding structures and/or adjacent lymph nodes. CTS seems to be unnecessary, if a submandibular tumour can be visualized by US and CECT.

Adenoma, Pleomorphic↗

[Clinical study of maxillofacial fractures sustained during sports and games].

We performed a clinico-statistical study of the maxillofacial fracture due to sports during the period of 15 years between 1977 and 1991. Eighty-nine patients were seen with injuries resulting from 21 different sports. The incidence of the fracture was most common in rugby, followed by ski, baseball and soccer. Males were shown to be more prone to maxillofacial fracture than females (5.4:1) and the highest incidence of injuries involved the 20-29 age group followed by the 10-19 age group. The major parts of the fracture were the mandible and the alveolar process. Conservative therapy such as maxillomandibular fixation was usually performed and the clinical course was good. It was suggested that the prevention of the sports-related fracture and the time of returning to sports after the fracture will require further study.

Adolescent↗

Ultrasonic diagnosis of oral and neck malignant lymphoma.

A series of 14 patients with nodal and extranodal non-Hodgkin's lymphoma of the oral and neck region was analyzed by ultrasonogram evaluation. Eight nodal lymphomas and six extranodal lymphomas commonly exhibited almost completely similar ultrasonographic findings, specifically, clear delineation of the boundary echo and a homogeneous, weak internal echo, the so-called pseudo-liquid-like images. The results derived from our study suggest that ultrasonic diagnosis is also helpful in evaluating patients with lymphoma during the initial diagnosis and initial treatment like other diagnostic imaging modalities.

Adult↗