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Biomedical subjects

T Amagasa

Publications and source records attributed to T Amagasa.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Dental treatment in the north area of Ishigaki Island in Okinawa].

Dental treatment and oral health care were performed on inhabitants in the north area of Ishigaki Island in Okinawa. There are no dentists in the area at present. One hundred sixty-six patients received treatment taking 528 man-days, during the period from November 9 to December 8, 2000. The area has 2 primary schools and 1 junior high school. The average DMFT of the children in the primary schools was 1.31, and in the junior high school it was 4.98. Compared with Japanese national survey data, the children in the area had a higher DMFT. Among the treatment procedures, the rate of conservative treatment was 62%, most of which was composite resin filling. Preventive measures for dental disease were offered to the inhabitants by means of topical fluoride application or oral health education. The period of this promotion was too short to perform complete dental treatment and to prevent caries and periodontal disease. It seems that primary prevention and higher dental hygiene education are needed for inhabitants in no-dentist areas, because the inhabitants do not have access to dental service easily.

Community Dentistry↗
PubMed2001

Preliminary psychologic survey of orofacial outpatients. Part 1: Predictors of anxiety or depression.

AIMS: To identify predictors for anxiety and depression in orofacial outpatients and to investigate the patients' compliance rate in taking a series of psychologic tests. METHODS: Three thousand six hundred sixty-six patients completed a battery of questionnaires. These consisted of items inquiring about sex, age, past history of disease, presence of pain, the Hospital Anxiety and Depression Scale (HADS), the Eysenck Personality Questionnaire Short Form (S-EPQ), a Japanese dental version of the McGill Pain Questionnaire (JDMPQ), a visual analog scale (VAS) of pain, pain duration, and diagnosis. After univariate analyses had determined those variables with significant differences between an over-probable group (OPG, HADS scores > or = 8) and an absent group (AG, HADS scores < 8), we estimated the odds ratios of these variables for OPG as independent variables, and every variable was adjusted between the independent variables by multiple logistic regression models. RESULTS: For anxiety, 3 variables were independently related to the OPG and considered to be meaningful: age 30 or older, neuroticism score on the S-EPQ, and selection of the JDMPQ pain expression term "sickening." For depression, 4 variables were independently related to the OPG and considered to be meaningful: age 30 or older, neuroticism and extroversion scores on the S-EPQ, and selection of the JDMPQ pain expression term "sickening." The compliance rate for the tests was under half of the patients (3,666 of 7,542 patients). CONCLUSION: Although the predictability for anxiety or depression by some baseline parameters is considered to be low, age, personality traits, and choice of certain pain expression terms are useful predictors of anxiety or depression. The improvement of the compliance rate for psychologic screening will be a future challenge for Japanese clinics managing orofacial patients.

Adult↗
PubMed2001

P53 and MDM2 co-expression in tobacco and betel chewing-associated oral squamous cell carcinomas.

Oral cancers of tobacco and betel chewers represents a unique in-vivo model to understand the genotoxic effect of tobacco and betel carcinogens on oncogenes and tumor suppressor genes. Coordinated interactions of p53 and MDM2 play an important role in regulation of critical growth control gene following exposure to DNA damaging agents. The purpose of this study is to determine if the tumor suppressor function of p53 is inactivated by mutation or other alternative mechanisms in carcinogen-induced oral squamous cell carcinoma (SCC), and to investigate the clinicopathological significance of p53 and MDM2 expression. The p53 mutation in oral SCC of tobacco and betel chewers (n=40) was detected by polymerase chain reaction - single strand conformation polymorphism (PCR-SSCP) analysis and immunohistochemistry (IHC) was done to investigate p53 and MDM2 proteins overexpression. The incidence of p53 mutation was relatively low (17.5%), but there was a high prevalence of MDM2 overexpression (72.5%). In the total of 40 cases, IHC phenotype showed p53 positive immunostaining with MDM2 positive immunostaining (p53+/MDM2+) 62.5%, p53 negative immunostaining with MDM2 negative immunostaining (p53-/MDM2-) 15%, p53 positive immunostaining with MDM2 negative immunostaining (p53+/MDM2-) 12.5%, and p53 negative immunostaining with MDM2 positive immunostaining (p53-/MDM2+) 10%. A significant correlation was found between MDM2 and p53 overexpression (p=0.0289). Moreover, p53+/MDM2+ phenotype was significantly associated with poorly differentiated tumors (p= 0.0007). These results conclude that other factors than p53 mutation is likely to be the targets of tobacco/betel carcinogens and MDM2 may play an important role in tobacco/betel chewing-related oral SCCs. Overexpression of MDM2 protein may constitute an alternative mechanism for p53 inactivation.

Areca↗
PubMed2000

ASK1 inhibits interleukin-1-induced NF-kappa B activity through disruption of TRAF6-TAK1 interaction.

Apoptosis signal-regulating kinase 1 (ASK1) is a member of the MAPKKK family in the JNK and p38 mitogen-activated protein kinase cascades and critically involved in stress- and cytokine-induced apoptosis. The transcription factor nuclear factor-kappaB (NF-kappaB) is a pivotal regulator of immune and inflammatory responses and exerts anti-apoptotic roles in various cells. Here we show that ASK1 directly interacts with transforming growth factor-beta-activated kinase 1 (TAK1), another MAPKKK that has been identified as a signaling intermediate in the interleukin 1 (IL-1)-induced NF-kappaB pathway as well as the transforming growth factor-beta superfamily-induced JNK/p38 pathway. Overexpression of ASK1 inhibits IL-1-, TRAF6-, or TAK1-induced, but not NF-kappaB-inducing kinase-induced, NF-kappaB activation. ASK1 dissociates TAK1 but not NF-kappaB-inducing kinase from TRAF6. Moreover, IL-1-induced complex formation of endogenous TAK1 and TRAF6 was blocked by ASK1 overexpression. It thus appears that the inhibition of NF-kappaB by ASK1 may result at least in part from the disruption of the TRAF6.TAK1 complex formation in the IL-1 signaling pathway. These results provide a new insight in the mode of action of MAPKKK family members; two distinct MAPKKKs in the same MAP kinase cascades directly interact and exert opposite effects in another signaling pathway, NF-kappaB.

Cell Line↗
PubMed2000

Meltrin beta (ADAM19) gene: cloning, mapping, and analysis of the regulatory region.

Meltrin beta (ADAM19) is a member of the metalloprotease-disintegrin family. We report here chromosomal mapping of the mouse and rat meltrin beta genes and cloning and analysis of the mouse upstream regulatory regions. The meltrin beta transcript shows a spatially and temporally restricted expression pattern during morphogenesis, indicating that the actions of this membrane-bound protease are regulated, at least in part, at the transcriptional level. Analysis of the promoter revealed positive and negative regulatory regions upstream of the gene. The former includes a GC-box that appears to be a critical cis-element for activation of the promoter in muscle cells.

ADAM Proteins↗
PubMed2000

Radiotherapy for primary localized (stage I and II) non-Hodgkin's lymphoma of the oral cavity.

PURPOSE: To assess the role of radiation therapy in the treatment of primary localized (Stage I: 24 cases and Stage II: 13 cases) non-Hodgkin's Lymphoma (NHL) of the oral cavity. METHODS AND MATERIALS: In total, 37 patients (27 male, 10 female) with primary localized NHL of the oral cavity have been treated with radiotherapy alone (23 cases) or radiation with chemotherapy (14 cases). The age range was 29 to 86 years (median: 65). Clinical and treatment variables with potential prognostic significance for survival were evaluated by univariate and multivariate analysis. Of the 37 patients, 31 (84%) had intermediate-grade lymphomas and six (14%) had high-grade lymphomas. Four patients showed necrotic ulcer in the central portion of the hard palate. RESULTS: The 5-year actuarial survival rate for all cases was 73%. The 5-year survival rates for intermediate-grade and high-grade lymphoma were 85% and 14%, respectively. Significant prognostic factors identified by the multivariate analysis were histologic grade of malignancy (p = 0.02) and central necrotic ulcer in the tumor (p = 0.02). Chemotherapy did not improve survival (p = 0.41). CONCLUSIONS: Our analysis suggests that radiotherapy alone may be approved as the treatment for localized oral NHL with no ulceration and intermediate histology. However, patients with high-grade lymphoma and/or necrotic ulcer are difficult to cure with radiation alone and aggressive treatment should be advocated to improve survival.

Adult↗
PubMed2000

Correlation between tumor consistency and cervical metastasis in tongue carcinoma.

BACKGROUND: The purpose of this study was to assess the correlation between the tumor consistency and cervical lymph node metastasis in tongue carcinoma. METHODS: Fifty-three patients with squamous cell carcinoma of the tongue were examined with an instrument capable of measuring consistency. These cases were compared in relation to TN classification, pathologic status of nodes, and consistency. RESULTS: The mean values of consistency in tongue carcinoma were 19. 7 +/- 2.9 g, 13.6 +/- 3.7 g, 27.4 +/- 4.5 g, and 21.2 +/- 6.7 g, corresponding to pathologically positive node group (PN[+]) in T1, pathologically negative node group (PN[-]) in T1, PN(+) in T2, and PN(-) in T2, respectively. Difference in consistency between PN(+) and PN(-) was significant (T1: p <.01, T2: p <.05). In the N0 patients, difference in consistency between PN(+) and PN(-) was also significant (p <.01). CONCLUSIONS: We suggest that quantitative evaluation of tumor consistency would be useful in determining whether selective neck dissections can safely be omitted in some patients.

Adult↗
PubMed2000

Human oral squamous cell carcinoma cell lines promote angiogenesis via expression of vascular endothelial growth factor and upregulation of KDR/flk-1 expression in endothelial cells.

Angiogenesis is an important phenomenon for the growth and metastasis of solid tumors. The present study examined the characterization of angiogenic factors produced by human oral squamous cell carcinoma (oral SCC) cell lines established from lymph node metastatic tumors and primary tumor in different patients. The conditioned medium of HSC3 with the strongest metastatic ability among the examined lines enhanced a tube-forming activity of bovine carotid artery endothelial (BAE) cells in collagen gel cultures. The treatment of HSC3 with anti-vascular endothelial growth factor (VEGF) antibody or anti-basic fibroblast growth factor (bFGF) antibody, either alone or in combination, attenuated the activity of urokinase-type plasminogen activator (uPA) in the endothelial cells stimulated by the conditioned medium of HSC3. In contrast, neither anti-interleukin-8 (IL-8) antibody nor anti-hepatocyte growth factor (HGF beta) antibody affected uPA activity in the endothelial cells. Among these HSC cell lines, HSC3 secreted VEGF with the highest (1.92 +/- 0.24 ng/10(6) cells/24 h) level and bFGF. The level of bFGF secreted by HSC3 was lower than that secreted by BAE cells. Other oral SCC cell lines secreted lower levels of VEGF and undetectable levels of bFGF. By reverse transcriptase-polymerase chain reaction analysis of mRNA the production of VEGF121, VEGF145, VEGF165, VEGF189, and VEGF206 in these cell lines was able to be detected. Moreover, the conditioned medium of HSC3 enhanced the tyrosine phosphorylation and expression of kinase insert domain-containing receptor (KDR/flk-1) in the endothelial cells. These results suggest that oral SCC promotes angiogenesis via expression of VEGF and upregulation of their receptor KDR/flk-1 expression in endothelial cells.

Aged↗
PubMed2000

Genetically high susceptibility to oral squamous cell carcinoma in terms of combined genotyping of CYP1A1 and GSTM1 genes.

An association of oral squamous cell carcinoma (SCC) susceptibility with an MspI restriction site polymorphism of the CYP1A1 gene and GSTM1 polymorphism were reported in our previous study (Sato M, Sato T, Izumo T, Amagasa T. Genetic polymorphism of drug-metabolizing enzymes and susceptiblility to oral cancer. Carcinogenesis 1999;20:1927-31). We report here that genetic risk for oral SCC was associated with another isoleucine-valine (Ile-Val) polymorphism, which resulted in an Ile-Val amino acid replacement in the heme-binding region of CYP1A1, and combined genotyping of CYP1A1 and GSTM1 genes in relation to the cumulative cigarette-smoking dose. The genetic polymorphisms of CYP1A1 and GSTM1 genes in oral cancer susceptibility were assessed by examining polymorphic prevalences in 142 oral SCC patients and 142 healthy controls who were individually matched to the patients with respect to sex and age (+/-1 year). Individuals with a combined genotype of Val/Val and GSTM1(-) were at an increased risk for oral SCC compared with other combined genotypes, in particular, at a low dose level of cigarette smoking.

Carcinoma, Squamous Cell↗
PubMed2000

Differential diagnosis of calcium pyrophosphate dihydrate deposition of the temporomandibular joint.

Calcium pyrophosphate dihydrate (CPPD) deposition disease (pseudogout) of the temporomandibular joint (TMJ) is rare. It is characterized by the presence of crystal deposits that are birefringent under polarized light. Although these crystals are characteristically weakly birefringent, some other crystals such as those of calcium oxalate, synthetic steroids, and ethylenediaminetetraacetic acid are also birefringent. The differential diagnosis should therefore be based on a quantitative analysis of crystals or observation of the crystal structure in calcified sections. We present a case of CPPD deposition disease of the TMJ and report on the value of such an analysis to substantiate the diagnosis.

Biopsy↗
PubMed2000

4p- syndrome and 9p tetrasomy mosaicism with cleft lip and palate.

Chromosome 4p- syndrome is a multiple malformation syndrome associated with partial deletion of the short arm of chromosome 4 (4p-). It is characterized by dysmorphic features and retarded development. Cleft lip and/or palate are the major clinical manifestations. Cases of tetrasomy 9p are extremely rare; the principal clinical manifestations of this condition are characteristic craniofacial abnormalities, generalized hypotonia and severe mental retardation. We present the first case of a female infant with 4p deletion and tetrasomy 9p mosaicism, exhibiting a left-sided cleft lip, alveolus and soft palate. Karyotype analysis of lymphocytes cultured from the patient revealed that she was mosaic: 86% of the cells were 46, XX, add (4) (p15.32) and 14% were 47, XX, add (4) (p15.32), +idic (9)(q12). The G-banding pattern appeared consistent with either translocation or partial proximal deletion of 4p. In order to make a definitive cytogenetic diagnosis of isodicentric chromosome 9, fluorescence in situ hybridization (FISH) was applied. At 8 months, when the patient weighed 4.3 kg, her cleft lip was repaired. Before and after surgery there were no seizures, and the postoperative course was uneventful.

Abnormalities, Multiple↗
PubMed2000

Synovial chondromatosis of the left temporomandibular joint superficially resembling chondrosarcoma: a case report.

A 25 year-old woman was referred to the clinic complaining of pain in the left temporomandibular joint (TMJ) and trismus. According to the x-ray images, a solitary mass was observed in the anterior pouch of the lower joint cavity. The mass was removed by means of a synovectomy and a diskectomy. Upon light microscopic examination, the tissue removed showed high cellular activity. As a differential diagnosis, we had to consider the possibility of chondrosarcoma based on the histopathological features; however, since no invasive nor metastatic finding was recognized, we made a diagnosis of synovial chondromatosis despite its rare existence. Although there has been no sign of recurrence at present, we plan to carefully follow up with the patient.

Adult↗
PubMed2000

Nonrandom chromosomal imbalances in esophageal squamous cell carcinoma cell lines: possible involvement of the ATF3 and CENPF genes in the 1q32 amplicon.

Using comparative genomic hybridization (CGH), we investigated copy number aberrations in 29 esophageal squamous cell carcinoma (ESC) cell lines. All lines displayed numerous chromosome imbalances. The most frequent losses were observed on chromosome 18q (65.5%), Xp (48. 3%), 3p (44.8%), 4q (44.8%), 8p (41.4%), 11q23 - 25 (34.5%) and 4p (27.6%), whereas the most common copy number gains were noted at 8q (86.2%), 3q (82.8%), 5p (69%), 7p (69%), 20q (65.5%), 9q (55.2%), 11q (55.2%), 1q (48.3%), Xq (44.8%) and 18p (37.9%). High-level gains (HLGs) were detected at 3q26 (9 cases), 8q23 (6 cases), 5p14 - 15 (6 cases), 18p11.2 - 11.3 (6 cases), 3q27 - 28 (5 cases), 5p13 (3 cases), 7p14 - 15 (3 cases), 20q12 - 13 (3 cases), 11q13 (3 cases), 14q21 (2 cases), 20p11.2 (2 cases), 13q32 (2 case), and 1q32 (1 case). Among them, HLGs of 1q32 have been reported in other types of cancer, including glioblastoma and breast cancers. We successfully narrowed down the smallest common amplicon involving 1q-gain to the genomic segment between D1S414 and D1S2860 by fluorescence in situ hybridization (FISH). Southern and northern blot analysis clearly demonstrated that ATF3, human activating transcription factor-3 and CENPF, centromere protein F, mapped within this region, were significantly amplified and over-expressed in 1q32 amplicon.

Activating Transcription Factor 3↗
PubMed2000

A case of false median cleft of upper lip with IV-A holoprosencephaly that underwent cheiloplasty at 2.5 years of age.

Holoprosencephaly results from the incomplete development of midline structures within the cerebrum and encompasses a series of abnormalities of mid-facial development. Here, we report a case of male holoprosencephaly associated with false median cleft of upper lip. This patient belonged clinically to the DeMyer's group IV holoprosencephaly, semilobar type. An infant with this type of holoprosencephaly has been thought to die generally within 1 to 2 years after birth and to rarely benefit from an operation. In this case, the patient had cheiloplasty at the age of 2.5 years at the request of his parents and he lives currently, being 3 years and 2 months old.

Child, Preschool↗
PubMed2000

Non-invasive densitometric and histomorphometric study of the regenerated bone in the distraction gap in rabbits.

The long period of external fixation after the completion of distraction, which is necessary to obtain enough strength for resisting without fixation is a significant disadvantage of distraction osteogenesis. The purpose of this study is to understand the mechanical property of the regenerated bone and try to find an appropriate timing for safely removing the fixation device. An external fixation device was applied to the right tibia in rabbits and transverse osteotomy was performed just below the tibio-fibula junction. The tibiae were lengthened 7.2 mm at 0.72 mm a day for 10 days after surgery. A bone mineral density (BMD) and stress strain index (SSI) analyzed by peripheral quantitative computed tomography showed a significant increase on day 40, but returned to the control level at day 64 after the completion of distraction. Therefore, the newly formed bone between the host cortical bone seemed to be enough to resist the mechanical stress on day 40 during the consolidation period in this study. The present results suggested the possibility of removing the fixation device during the period when the BMD and SSI showed a significantly high level during the consolidation period.

Absorptiometry, Photon↗
PubMed1999

The role of recombinant human bone morphogenetic protein-2 in PLGA capsules at an extraskeletal site of the rat.

Bone morphogenetic protein-2 (BMP-2) is a member of the transforming growth factor-beta (TGF-beta) superfamily and has strong bone-inductive activity in vivo. To examine the role of BMP-2 in an extraskeletal site of rat using a controlled release system of peptides, we encapsulated the recombinant human BMP-2 (rhBMP-2) with poly(DL-lactide-co-glycolide) (PLGA) and implanted the rhBMP-2/PLGA capsules in the subcutaneous area of rats. Upon histochemical examination, it was found that bone-inducing cells having alkaline phosphatase (ALP) activity appeared around the capsules by the suitably released rhBMP-2. In addition, the temporal histological examination showed that direct bone formation without cartilage occurred in the process of this ectopic bone induction. These data indicate that the role of rhBMP-2 in the extraskeletal site of rats is to induce the differentiation of mesenchymal cells into the osteoblasts.

Alkaline Phosphatase↗
PubMed1999

Caspase-3 activation during the process of apoptosis induced by a vacuolar type H(+)-ATPase inhibitor.

Concanamycin A, a specific inhibitor of vacuolar type H(+)-ATPases, induced DNA fragmentation in B cell hybridoma HS-72 cells. Immunoblot analysis revealed that the exposure of concanamycin A to HS-72 cells induced the cleavage of retinoblastoma protein (Rb) and poly(ADP-ribose) polymerase (PARP). The cytosol from concanamycin A-treated HS-72 cells induced DNA fragmentation in nuclei from untreated cells in a cell-free system. This fragmentation was suppressed by a specific inhibitor of caspase-3. The cytosol induced Rb proteolysis in vitro, which was inhibited by a caspase-3 inhibitor. These findings indicate that caspase-3 induces DNA fragmentation and cleavage of Rb and PARP during the process of apoptosis induced by concanamycin A.

Animals↗